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SAO/NASA ADS Astronomy Abstract Service

Title:              Minor Planet Observations [H49 ATU Astronomical 
                    Observatory, Russellville]
Authors:            Robertson, J. W.; Ahrns, M. J.
Publication:        Minor Planet Circular 61176, 5 (2007)
Publication Date:   11/2007
Origin:             MPC
Bibliographic Code: 2007MPC..61176...5R

Abstract

Not Available

Title:              Late-Type Near-Contact Eclipsing Binary [HH97] FS 
                    Aur-79
Authors:            Austin, S. J.; Robertson, J. W.; Tycner, C.;
                    Campbell, T.; Honeycutt, R. K.
Affiliation:        AA(Department of Physics and Astronomy, University 
                    of Central Arkansas, Conway, AR 72035, USA; 
                    ), AB(Department of Physical Sciences, Arkansas Tech University, Russellville, AR 72801-2222, USA; ), AC(US Naval Observatory, Flagstaff Station, Flagstaff, AZ 86001-8521, USA; ), AD(Whispering Pines Observatory, Harrison, AR 72601, USA; ), AE(Department of Astronomy, Indiana University, Bloomington, IN 47405, USA; ) 

Publication:        The Astronomical Journal, Volume 133, Issue 5, pp. 
                    1934-1946. (AJ Homepage)
Publication Date:   05/2007
Origin:             UCP
AJ Keywords:        Stars: Binaries: Close, Stars: Binaries: Eclipsing, 
                    Stars: Binaries: Spectroscopic, Stars: Late-Type
Abstract Copyright: (c) 2007: The American Astronomical Society
DOI:                10.1086/512614
Bibliographic Code: 2007AJ....133.1934A

Abstract

The secondary photometric standard star number 79 for the FS Aur field (Henden & Honeycutt 1997), designated as [HH97] FS Aur-79 (GSC 1874-399), is a short-period (0.2508 days) eclipsing binary whose light curve is a combination of the β Lyr and BY Dra type variables. High signal-to-noise ratio multicolor photometry was obtained using the US Naval Observatory 1 m telescope. These light curves show asymmetry at quadrature phases (the O'Connell effect), which can be modeled with the presence of starspots. A low-resolution spectrum obtained with the 3.5 m Wisconsin-Indiana-Yale-NOAO telescope at orbital phase 0.76 is consistent with a spectral type of dK7e and dM3e. A radial velocity curve for the primary star was constructed using 24 high-resolution spectra from the 9.2 m Hobby-Eberly Telescope. Spectra show Hα and Hβ in emission confirming chromospheric activity and possibly the presence of circumstellar material. Binary star models that simultaneously fit the U, B, V, R, and radial velocity curves are those with a primary star of mass 0.59+/-0.02 M_solar, temperature 4100+/-25 K, and mean radius 0.67 R_solar, just filling its Roche lobe, and a secondary star of mass 0.31+/-0.09 M_solar, temperature 3425+/-25 K, and mean radius 0.48 R_solar, just within its Roche lobe. An inclination angle of 83^deg+/-2^deg with a center-of-mass separation of 1.62 R_solar is also derived. Starspots, expected for a rotation period of less than 1 day, had to be included in the modeling to fit the O'Connell effect.

Title:              A Photometric and Spectroscopic Study of the 
                    Cataclysmic Variable ST LMi during 2005-2006
Authors:            Kafka, S.; Howell, S. B.; Honeycutt, R. K.;
                    Robertson, J. W.
Affiliation:        AA(Cerro Tololo Inter-American Observatory, NOAO, La 
                    Serena, Chile ; Visiting Astronomer, Kitt Peak 
                    National Observatory, National Optical Astronomy 
                    Observatory ), AB(Visiting Astronomer, Kitt Peak 
                    National Observatory, National Optical Astronomy 
                    Observatory ; WIYN Observatory and NOAO, Tucson, AZ 
                    85719, USA ), AC(Visiting Astronomer, Kitt Peak 
                    National Observatory, National Optical Astronomy 
                    Observatory ; Astronomy Department, Indiana 
                    University, Bloomington, IN 47405, USA ), 
                    AD(Visiting Astronomer, Kitt Peak National 
                    Observatory, National Optical Astronomy Observatory 
                    ; Department of Physical Sciences, Arkansas 
                    Technical University, Russellville, AR 72801-2222, 
                    USA)
Publication:        The Astronomical Journal, Volume 133, Issue 4, pp. 
                    1645-1657 (2007). (AJ Homepage)
Publication Date:   04/2007
Origin:             IOP
DOI:                10.1086/511785
Bibliographic Code: 2007AJ....133.1645K

Abstract

We present orbit-resolved spectroscopic and photometric observations of the polar ST LMi during its recent low and high states. In the low-state spectra, we report the presence of blue and red satellites in the Hα emission line; the velocities and visibility of the satellites vary with phase. This behavior is similar to emission-line profile variations recently reported in the low state of AM Her, which were interpreted as being due to magnetically confined gas motions in large loops near the secondary. Our low-state spectroscopy of ST LMi is discussed in terms of extreme chromospheric activity on the secondary star. Concurrent photometry indicates that occasional low-level accretion may be present, as well as cool regions on the secondary near the inner Lagrangian point, L1. Furthermore, we report a new "extreme low state" of the system at V ~ 18.5 mag. Our orbital high-state spectroscopy reveals changes in the emission-line profiles with orbital phases that are similar to those reported by earlier high-state studies. The complicated emission-line profiles generally consist of two main components. The first has radial velocity variations identical to that of the major emission Hα component seen in the low state. The second is an additional redshifted component appearing at the phases of maximum visibility of the accreting column of the white dwarf; it is interpreted as being due to infall velocities on the accreting magnetic pole of the white dwarf. At the opposite phases, an extended blue emission wing appears on the emission-line profiles. We confirm the presence of a broad absorption feature near 6275 Å, which has been previously identified as a Zeeman σ^- absorption component of Hα. This feature appears at just those phases when the accretion pole region is most directly visible and most nearly face-on to the observer.

Based on observations obtained with the Mayall 4 m telescope at Kitt Peak National Observatory, a division of the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.

Title:              Obtaining An MPC Observatory Code For Arkansas Tech 
                    University
Authors:            Ahrns, Jason; Robertson, J. W.
Affiliation:        AA(Arkansas Tech University), AB(Arkansas Tech 
                    University)
Publication:        2007 AAS/AAPT Joint Meeting, American Astronomical 
                    Society Meeting 209, #25.11; Bulletin of the 
                    American Astronomical Society, Vol. 38, p.935
Publication Date:   12/2006
Origin:             AAS
Abstract Copyright: (c) 2006: American Astronomical Society
Bibliographic Code: 2006AAS...209.2511A

Abstract

We report on our experiences in obtaining an official Minor Planet Center observatory code for the Arkansas Tech University Astronomical Observatory. Information is presented on the equipment and techniques used to provide the MPC with accurate coordinates of minor planets using a small campus observatory with undergraduate students resulting in a successful designation of H49 for the ATU observatory by the MPC.

Title:              A 2006 Spectroscopic Study of ST LMi
Authors:            Honeycutt, R. K.; Kafka, S.; Howell, S. B.;
                    Robertson, J. W.
Affiliation:        AA(Indiana Univ), AB(CTIO/NOAO, Chile), 
                    AC(WIYN/NOAO), AD(Arkansas Tech Univ.)
Publication:        2007 AAS/AAPT Joint Meeting, American Astronomical 
                    Society Meeting 209, #09.16; Bulletin of the 
                    American Astronomical Society, Vol. 38, p.909
Publication Date:   12/2006
Origin:             AAS
Abstract Copyright: (c) 2006: American Astronomical Society
Bibliographic Code: 2006AAS...209.0916H

Abstract

Orbit-resolved spectroscopic and photometric observations of the magnetic cataclysmic variable ST LMi were obtained at several epochs during the high state and during its recent low state. In the low state the H-alpha line is triple-peaked. The satellite components are attributed to gas motions near the secondary star, likely due to extreme chromospheric activity. We compare these activity signatures with similar structures in AM Her. In the high state the H-alpha profile is complex, having two main components plus an extended blue wing at some orbital phases, similar to previously-reported high-state behavior in this system.

Title:              Low-State Photometry of AM Her during 2005-06
Authors:            Robertson, Jeff W.; Kafka, S.; Honeycutt, K.;
                    Campbell, T.
Affiliation:        AA(Arkansas Tech University), AB(CTIO/NOAO, Chile), 
                    AC(Indiana University), AD(Whispering Pines 
                    Observatory)
Publication:        2007 AAS/AAPT Joint Meeting, American Astronomical 
                    Society Meeting 209, #09.08; Bulletin of the 
                    American Astronomical Society, Vol. 38, p.908
Publication Date:   12/2006
Origin:             AAS
Abstract Copyright: (c) 2006: American Astronomical Society
Bibliographic Code: 2006AAS...209.0908R

Abstract

We report on observations of the magnetic polar cataclysmic variable AM Her during its low-state. Photometry during 2005-06 reveal events that might be related to activity on the secondary star.

Title:              Minor Planet Observations [H49 ATU Astronomical 
                    Observatory, Russellville]
Authors:            Robertson, J. W.; Ahrns, M. J.
Publication:        Minor Planet Circular 57128, 13 (2006)
Publication Date:   07/2006
Origin:             MPC
Bibliographic Code: 2006MPC..57128..13R

Abstract

Not Available

Title:              The RXTE, ROSAT, IUE, EUVE, Optical Campaign 
                    Covering the 45-Day Supercycle of V1159 Orionis
Authors:            Szkody, P.; Honeycutt, K.; Robertson, J.;
                    Silber, A.; Hoard, D. W.; Pastwick, L.;
                    Hubeny, I.; Cannizzo, J.; Liller, W.;
                    Zissell, R.; Walker, G.; La Dous, C.; Drew, J.
Affiliation:        AA(University of Washington, Seattle), AB(Indiana 
                    University, Bloomington), AC(Indiana University, 
                    Bloomington), AD(University of Washington, Seattle), 
                    AE(University of Washington, Seattle), AF(University 
                    of Washington, Seattle), AG(NASA, Goddard Space 
                    Flight Center), AH(NASA, Goddard Space Flight 
                    Center), AJ(Mount Holyoke College, South Hadley, 
                    MA), AL(Sternwarte Sonneberg), AM(Imperial College, 
                    London)
Publication:        The Journal of the American Association of Variable 
                    Star Observers, Vol. 35, No. 1, p. 135
Publication Date:   06/2006
Origin:             AAVSO
Abstract Copyright: (c)2006: American Association of Variable Star 
                    Observers
Bibliographic Code: 2006JAVSO..35..135S

Abstract

A comprehensive data set covering the superoutburst and 8 outbursts of the 45-day supercycle of the dwarf nova V1159 Ori was obtained in Feb-Mar 1996. The use of RXTE, ROSAT, IUE, and EUVE satellites, combined with ground-based optical photometry and spectroscopy, provided a broad picture of the accretion disk at different states. Results include an inverse correlation of the X-ray with the UV/optical fluxes, an outflowing wind during all outbursts, and large changes in the disk spectrum on time scales of less than a day. These results are compared to other dwarf novae and general theories of dwarf nova outbursts.

Title:              New Pulsating Variable Discovered In The 
                    Constellation Andromeda
Authors:            Robertson, J. W.
Affiliation:        Arkansas Tech University
Publication:        Journal of the Arkansas Academy of Science Volume 
                    59, p.210-213
Publication Date:   04/2006
Origin:             AUTHOR
Keywords:           RRc pulsating variable
Bibliographic Code: 2006JAsAS..59L.210R

Abstract

A new pulsating variable star, [HH95] HV And-7, is found near the cataclysmic variable HV And, which is a part of the Indiana University RoboScope observing program (Honeycutt and Turner, 1992). A finding chart generated with Aladin software (Bonnarel et.al., 2000) is shown in Figure 1. Its coordinates are (J2000) 00°40'46.23" +43°23'57.9". This star was initially calibrated as a secondary photometric standard star with V=15.277 and B-V=0.281 for the field of HV And (Henden & Honeycutt, 1995), but it suspiciously had the largest standard deviation of the group of standards (stdev = 0.14). Its variability detailed here means that it can not be used as a photometric standard.

Title:              Low-State Flaring Events in AM Herculis
Authors:            Kafka, S.; Robertson, J.; Honeycutt, R. K.;
                    Howell, S. B.
Affiliation:        AA(Astronomy Department, Indiana University, 319 
                    Swain Hall West, Bloomington, IN 47405; 
                    , .), AB(Department of Physical Sciences, Arkansas Tech University, 1701 North Boulder Avenue, Russellville, AR 72801-2222 .), AC(Astronomy Department, Indiana University, 319 Swain Hall West, Bloomington, IN 47405; , .), AD(WIYN Observatory and NOAO, P.O. Box 26732, 9!
 50 North Cherry Avenue, Tucson, AZ 85719; .) 

Publication:        The Astronomical Journal, Volume 129, Issue 5, pp. 
                    2411-2419. (AJ Homepage)
Publication Date:   05/2005
Origin:             UCP
AJ Keywords:        Stars: Novae, Cataclysmic Variables, Stars: 
                    Individual: Constellation Name: AM Herculis
Abstract Copyright: (c) 2005: The American Astronomical Society
DOI:                10.1086/429133
Bibliographic Code: 2005AJ....129.2411K

Abstract

A photometric monitoring campaign has been conducted in order to investigate the character and origin of flaring events occasionally seen in the long-term low-state light curve of the polar prototype AM Her. Four telescopes employed during 2004 May-July revealed that the events have typical duty cycles of 2%-35%, amplitudes of 0.2-0.6 mag, and typical durations of 15-90 minutes. A striking concentration of the 2004 events appears near inferior and superior conjunction of the secondary star. Interestingly, in the long-term RoboScope-monitored light curve (1990-2003), similar events are uniformly distributed in phase. AM Her's accretion geometry and the nature of its low states allow for two likely origins for the observed events, namely, residual accretion during low states and activity (flares) on the secondary star. Considering that AM Her is likely a one-pole accretor in the low states, the former requires irregular mass transfer from the secondary, resulting in random accretion bursts, with cyclotron beaming concentrating the flares into two phase intervals. On the other hand, considering the stability of the magnetic poles, this cannot address the random distribution of the events during the long-term light curve. Drifting active regions on the secondary star could explain the random distribution of the events; however, coincidence must be invoked to explain their occurrence at the observed phases of orbital conjunction. A combination of the two ideas is also discussed, in which stellar activity on the secondary star induces random accretion bursts, with cyclotron beaming then concentrating the flares into two phase intervals.

Title:              A Photometric Study of the Low States of AM Her
Authors:            Robertson, J. W.; Kafka, S.; Honeycutt, R. K.;
                    Howell, S. B.
Affiliation:        AA(Arkansas Tech University), AB(Indiana 
                    University), AC(Indiana University), AD(WIYN/NOAO)
Publication:        American Astronomical Society Meeting 205, #19.03; 
                    Bulletin of the American Astronomical Society, Vol. 
                    36, p.1371
Publication Date:   12/2004
Origin:             AAS
Abstract Copyright: (c) 2004: American Astronomical Society
Bibliographic Code: 2004AAS...205.1903R

Abstract

We present a photometric study of the low states of AM Her. Long-term (RoboScope) and continuous monitoring reveal flaring events with amplitudes of 0.2-0.6 magnitude and durations of 15-90 minutes. These events, which appear to be frequent during the latest low state (2004 February - present), can be due to either residual accretion or activity (flares) on the secondary star. The advantages and drawbacks of both mechanisms are discussed in terms of what is known about the magnetic accretion geometry and low-state behavior of AM Her.

Title:              Rapid Oscillations in Cataclysmic Variables. XVI. DW 
                    Cancri
Authors:            Patterson, Joseph; Thorstensen, John R.;
                    Vanmunster, Tonny; Fried, Robert E.;
                    Martin, Brian; Campbell, Tut; Robertson, Jeff;
                    Kemp, Jonathan; Messier, David; Armstrong, Eve
Affiliation:        AA(Department of Astronomy, Columbia University, 550 
                    West 120th Street, New York, NY 10027; 
                    , .), AB(Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755; .), AC(Center for Backyard Astrophysics (Belgium), Walhostraat 1A, B-3401 Landen, Belgium; .), AD(Center for Backyard Astrophysics (Flagstaff), Braeside Observatory, Post Office Box 906, Flagstaff, AZ 86002; .), AE(Department of Physics, King's University College, 9125 50th Street, Edmonton, AB T5H 2M1, Canada; .), AF(Department of Physical Science, Arkansas Tech University, 1701 North Boulder Avenue, Russellville, AR 72801; , .), AG(Department of Physical Science, Arkansas Tech University, 1701 North Boulder Avenue, Russellville, AR 72801; , .), AH!
 (Joint A
stronomy Centre, University Park, 660 North Aòhōkū Place, Hilo, HI 96720; .; Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027; , .), AI(Center for Backyard Astrophysics (Norwich), 35 Sergeants Way, Lisbon, CT 06351; .), AJ(Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027; , .) 

Publication:        The Publications of the Astronomical Society of the 
                    Pacific, Volume 116, Issue 820, pp. 516-526. (PASP 
                    Homepage)
Publication Date:   06/2004
Origin:             UCP
PASP Keywords:      Accretion, Accretion Disks, Stars: Binaries: Close, 
                    Stars: Novae, Cataclysmic Variables, stars: 
                    individual (DW Cancri)
Abstract Copyright: (c) 2004: The Astronomical Society of the Pacific
DOI:                10.1086/421034
Bibliographic Code: 2004PASP..116..516P

Abstract

We report photometry and spectroscopy of the nova-like variable DW Cancri. The spectra show the usual broad H and He emission lines, with an excitation and continuum slope characteristic of a moderately high accretion rate. A radial-velocity search yields strong detections at two periods, 86.1015(3) minutes and 38.58377(6) minutes. We interpret these as respectively the orbital period P_orb of the binary, and the spin period P_spin of a magnetic white dwarf. The light curve also shows the spin period, plus an additional strong signal at 69.9133(10) minutes, which coincides with the difference frequency 1/P_spin-1/P_orb. These periods are stable over the 1 year baseline of measurement. This triply-periodic structure mimics the behavior of several well-credentialed members of the ``DQ Herculis'' (intermediate polar) class of cataclysmic variables. DQ Her membership is also suggested by the mysteriously strong sideband signal (at ν_spin-ν_orb), attesting to a strong pulsed flux at X-ray/EUV/UV wavelengths. DW Cnc is a new member of this class, and would be an excellent target for extended observation at these wavelengths.

Title:              An Eclipsing Near Contact Short Period Binary in the 
                    Field of FS Aur
Authors:            Robertson, J. W.; Austin, S. J.; Campbell, T.;
                    Hoskins, J.
Publication:        Information Bulletin on Variable Stars, 5536, 1. 
                    (IBVS Homepage)
Publication Date:   06/2004
Origin:             IBVS
Objects:            FS Aur
Keywords:           photometry
Abstract Copyright: Copyright: Konkoly Observatory, 2004
Comment:            5536-t1
Bibliographic Code: 2004IBVS.5536....1R

Abstract

This report discusses a new eclipsing binary near FS Aur.

Title:              New Eclipsing Contact Binary System in Auriga
Authors:            Austin, S. J.; Robertson, J. W.; Justice, C.;
                    Campbell, R. T.; Hoskins, J.
Affiliation:        AA(University of Central Arkansas), AB(Arkansas Tech 
                    University), AC(Arkansas Tech University), 
                    AD(Whispering Pines Observatory), AE(Nubbin Ridge 
                    Observatory)
Publication:        American Astronomical Society Meeting 204, #05.10; 
                    Bulletin of the American Astronomical Society, Vol. 
                    36, p.741
Publication Date:   05/2004
Origin:             AAS
Abstract Copyright: (c) 2004: American Astronomical Society
Bibliographic Code: 2004AAS...204.0510A

Abstract

We present data on a newly discovered eclipsing binary system. The serendipitous discovery of this variable star was made by J.W. Robertson analyzing inhomogeneous ensemble photometry of stars in the field of the cataclysmic variable FS Aurigae from Indiana University RoboScope data. We obtained differential time-series BVR photometry during 2003 of this field variable using an ensemble of telescopes including the university observatories at ATU, UCA and joint ventures with amateur observatories in the state of Arkansas (Whispering Pines Observatory and Nubbin Ridge Observatory).

The orbital period of this eclipsing system is 0.2508 days. The B-V light curve indicates colors of 1.2 around quadrature, to nearly 1.4 at primary eclipse. Binary star light curve models that best fit the BVR differential photometry suggest that the system is a contact binary overfilling the inner Roche Lobe by 12%, a primary component with a temperature of 4350K, a secondary component with a temperature of 3500K, a mass ratio of 0.37, and an inclination of 83 degrees. We present BVR light curves, an ephemeris, and best fit model parameters for the physical characteristics of this new eclipsing binary system.

Title:              Systematics of Superhumps in the Short Supercycle SU 
                    UMa Dwarf Nova V1159 Ori
Authors:            Pitts, M. A.; Robertson, J. W.; Honeycutt, R. K.
Affiliation:        AA(Indiana Univ. and Ohio State Univ.), AB(Arkansas 
                    Tech Univ.), AC(Indiana University)
Publication:        American Astronomical Society, 201st AAS Meeting, 
                    #40.11; Bulletin of the American Astronomical 
                    Society, Vol. 34, p.1163
Publication Date:   12/2002
Origin:             AAS
Abstract Copyright: (c) 2002: American Astronomical Society
Bibliographic Code: 2002AAS...201.4011P

Abstract

Lightcurves of the cataclysmic variable V1159 Orionis have been analyzied to study the outbursts, superoutbursts, and superhumps in this SU Uma-type dwarf nova. The data are merged from RoboScope observations over 7 years plus 3 years of CCD measures from amateur astronomers. The outbursts occur at an interval of ~4 days, with superoutbursts each 44.5 days. At times we find superhumps at all superoutburst phases, as well as a double-peaked structure within the star's ~0.06 day oscillations. These oscillations are often damped during the peaks of the normal outbursts, and a general strengthening occurs during superoutburst, peaking near the end of the superoutburst. This work was done as part of a summer REU program at Indiana University.

Title:              The 2001 Superoutburst of WZ Sagittae
Authors:            Patterson, Joseph; Masi, Gianluca;
                    Richmond, Michael W.; Martin, Brian;
                    Beshore, Edward; Skillman, David R.;
                    Kemp, Jonathan; Vanmunster, Tonny; Rea, Robert;
                    Allen, William; Davis, Stacey; Davis, Tracy;
                    Henden, Arne A.; Starkey, Donn; Foote, Jerry;
                    Oksanen, Arto; Cook, Lewis M.;
                    Fried, Robert E.; Husar, Dieter; Novák, Rudolf;
                    Campbell, Tut; Robertson, Jeff; Krajci, Thomas;
                    Pavlenko, Elena; Mirabal, Nestor;
                    Niarchos, Panos G.; Brettman, Orville; Walker, Stan
Affiliation:        AA(Department of Astronomy, Columbia University, 550 
                    West 120th Street, New York, NY 10027; 
                    , .), AB(Center for Backyard Astrophysics (Italy), Via Madonna de Loco, 47, 03023 Ceccano FR, Italy; .), AC(Rochester Institute of Technology, Department of Physics, 85 Lomb Memorial Drive, Rochester, NY 14623; , , .), AD(King's University College, Department of Physics, 9125 50th Street, Edmonton, AB T5H 2M1, Canada; .), AE(Center for Backyard Astrophysics (Colorado), 14795 East Coachman Drive, Colorado Springs, CO 80908; .), AF(Center for Backyard Astrophysics (East), 9517 Washington Avenue, Laurel, MD 20723; .), AG(Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027; , .; Joint Astronomy Centre, University Park, 660 North A`ohōkū Place, Hilo, HI 96720; .; Visiting Astronomer, Cerro Tololo Interamerican Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc. (AURA), under cooperative agreement with the National Science Foundation.), AH(Center for Backyard Astrophysics (Belgium), Walhostraat 1A, B-3401 Landen, Belgium; .), AI(Center for Backyard Astrophysics (Nelson), 8 Regent Lane, Richmond, Nelson, New Zealand; .), AJ(Center for Backyard Astrophysics (Blenheim), 83 Vintage Lane, RD 3, Blenheim, New Zealand; .), AK(Rochester Institute of Technology, Department of Physics, 85 Lomb Memorial Drive, Rochester, NY 14623; , , .), AL(Rochester Institute of Technology, Department of Physics, 85 Lomb Memorial Drive, Rochester, NY 14623; , , .), AM(United States Naval Observatory, Flagstaff Station, P.O. Box 1149, Flagstaff, AZ 86002; .), AN(Center for Backyard Astrophysics (Indiana), 2507 County Road 60, Auburn, IN 46706; .), AO(Center for Backyard Astrophysics (Utah), 4175 East Red Cliffs Drive, Kanab, UT 84741; .), AP(Center for Backyard Astrophysics (Finland), Vertaalantie 449, Nyrölä, Finland; .), AQ(Center for Backyard Astrophysics (Concord), 1730 Helix Court, Concord, CA 94518; .), AR(Center for Backyard Astrophysics (Flagstaff), Braeside Observatory, P.O. Box 906, Flagstaff, AZ 86002; .), AS(Center for Backyard Astrophysics (Hamburg), Himmelsmoor 18, D-22397 Hamburg-Duvenstedt, Germany; .), AT(Nicholas Copernicus Observatory, Kravi Hora 2, Brno 616 00, Czech Republic; .), AU(Arkansas Tech Univer!
 sity, De
partment of Physical Science, 1701 North Boulder Avenue, Russellville, AR 72801; , .), AV(Arkansas Tech University, Department of Physical Science, 1701 North Boulder Avenue, Russellville, AR 72801; , .), AW(Center for Backyard Astrophysics (New Mexico), 1688 Cross Bow Circle, Clovis, NM 88101; .), AX(Crimean Astrophysical Obse!
 rvatory, P/O Nauchny, 334413 Crimea, Ukraine; .), AY(Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027; , .), AZ(University of Athens, Department of Astrophysics, Astronomy, and Mechanics, Panepistimipolis, GR-157 84, Zografos, Athens, Greece; .), BA(Center for Backyard Astrophysics (Huntley), 13915 Hemmingsen Road, Huntley, IL 60142; .) 

Publication:        The Publications of the Astronomical Society of the 
                    Pacific, Volume 114, Issue 797, pp. 721-747. (PASP 
                    Homepage)
Publication Date:   07/2002
Origin:             UCP
PASP Keywords:      accretion, accretion disks, Stars: Binaries: Close, 
                    Stars: Novae, Cataclysmic Variables, Stars: 
                    Individual: Constellation Name: WZ Sagittae
Abstract Copyright: (c) 2002: The Astronomical Society of the Pacific
Bibliographic Code: 2002PASP..114..721P

Abstract

We report the results of a worldwide campaign to observe WZ Sagittae during its 2001 superoutburst. After a 23 yr slumber at V=15.5, the star rose within 2 days to a peak brightness of 8.2, and showed a main eruption lasting 25 days. The return to quiescence was punctuated by 12 small eruptions, of ~1 mag amplitude and 2 day recurrence time; these ``echo outbursts'' are of uncertain origin, but somewhat resemble the normal outbursts of dwarf novae. After 52 days, the star began a slow decline to quiescence. Periodic waves in the light curve closely followed the pattern seen in the 1978 superoutburst: a strong orbital signal dominated the first 12 days, followed by a powerful common superhump at 0.05721(5) day, 0.92(8)% longer than P_orb. The latter endured for at least 90 days, although probably mutating into a ``late'' superhump with a slightly longer mean period [0.05736(5) day]. The superhump appeared to follow familiar rules for such phenomena in dwarf novae, with components given by linear combinations of two basic frequencies: the orbital frequency ω_o and an unseen low frequency Ω, believed to represent the accretion disk's apsidal precession. Long time series reveal an intricate fine structure, with ~20 incommensurate frequencies. Essentially all components occurred at a frequency nω_o-mΩ, with m=1, ..., n. But during its first week, the common superhump showed primary components at nω_o-Ω, for n=1, 2, 3, 4, 5, 6, 7, 8, 9 (i.e., m=1 consistently); a month later, the dominant power shifted to components with m=n-1. This may arise from a shift in the disk's spiral-arm pattern, likely to be the underlying cause of superhumps. The great majority of frequency components are redshifted from the harmonics of ω_o, consistent with the hypothesis of apsidal advance (prograde precession). But a component at 35.42 cycles day^-1 suggests the possibility of a retrograde precession at a different rate, probably N=0.13+/-0.02 cycles day^-1. The eclipses permit measuring the location and brightness of the mass-transfer hot spot. The disk must be very eccentric and nearly as large as the white dwarf's Roche lobe. The hot-spot luminosity exceeds its quiescent value by a factor of up to 60. This indicates that enhanced mass transfer from the secondary plays a major role in the eruption.

Title:              Long-Term Optical and X-Ray Observations of the Old 
                    Novae DI Lacertae and V841 Ophiuchi
Authors:            Hoard, D. W.; Szkody, Paula; Honeycutt, R. K.;
                    Robertson, Jeff; Desai, Vandana; Hillwig, T.
Affiliation:        AA(Cerro Tololo Inter-American Observatory, Casilla 
                    603, La Serena, Chile; 
                    ), AB(Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 ), AC(Astronomy Department, Indiana University, Swain Hall West 319, Bloomington, IN 47505; ), AD(Department of Physical Sciences, Arkansas Technical University, Russellville, AR 72801-2222 ), AE(Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 ), AF(Astronomy Department, Indiana University, Swain Hall West 319, Bloomington, IN 47505; ) 

Publication:        The Publications of the Astronomical Society of the 
                    Pacific, Volume 112, Issue 778, pp. 1595-1606. 
                    (PASP Homepage)
Publication Date:   12/2000
Origin:             UCP
PASP Keywords:      accretion, accretion disks, Stars: Novae, 
                    Cataclysmic Variables, stars: individual (DI 
                    Lacertae), stars: individual (V841 Ophiuchi)
Abstract Copyright: (c) 2000: The Astronomical Society of the Pacific
Bibliographic Code: 2000PASP..112.1595H

Abstract

We present an analysis of ground-based optical photometry and spectroscopy and Rossi X-Ray Timing Explorer X-ray observations of the old novae DI Lacertae and V841 Ophiuchi. Our optical photometry data (obtained with the automated photometry telescope RoboScope) comprise an almost decade-long light curve for each star, while the contemporaneous spectroscopy and X-ray observations repeatedly sampled each nova during separate intervals of ~45-55 days in length. The long-term optical light curves of both novae reveal quasi-periodic variability on typical timescales of ~30-50 days with amplitudes of ΔV~0.4-0.8 mag. V841 Oph also displays a long-term, sinusoidal modulation of its optical light on a timescale of 3.5-5 yr. The optical spectra of these novae display quite different characteristics from each other, with DI Lac showing narrow Balmer emission cores situated in broad absorption troughs while V841 Oph exhibits strong single-peaked Balmer, He I, and He II emission lines. We find little change between spectra obtained during different optical brightness states. The X-ray count rates for both novae were very low (<~1.5 counts s^-1), and there was no reliable correlation between X-ray and optical brightness. The combined X-ray spectrum of DI Lac is best fit by a bremsstrahlung emission model (with kT~4 keV and N_H<1.8×10²² cm^-3) the X-ray spectrum of V841 Oph is too weak to allow model fitting. We discuss the possible origin of variability in these old novae in terms of magnetic activity on the secondary star, dwarf nova type disk instabilities, and the ``hibernation'' scenario for cataclysmic variable stars. Based on observations with the Apache Point Observatory 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium, and on observations with the WIYN Observatory 3.5 m telescope, which is jointly operated by the University of Wisconsin, Indiana University, Yale University, and the National Optical Astronomy Observatories.

Title:              Supercycle Superoutburst Timings
Authors:            Robertson, J. W.; Honeycutt, R. K.
Affiliation:        AA(Arkansas Tech University), AB(Indiana University)
Publication:        American Astronomical Society, 197th AAS Meeting, 
                    #85.10; Bulletin of the American Astronomical 
                    Society, Vol. 32, p.1549
Publication Date:   12/2000
Origin:             AAS
Abstract Copyright: (c) 2000: American Astronomical Society
Bibliographic Code: 2000AAS...197.8510R

Abstract

The ability to establish the time of maximum light is important for many different types of variable stars. We present a method for accurately timing superoutbursts in SU UMa-type cataclysmic variables. The shape of superoutbursts in SU UMa stars are very uniform for any individual star (although widely varying from star to star). Their also exists a smooth linear decline after maximum light that lasts several days. By observing a star during this period, only two observations separated by hours to days are required to make a linear fit, enabling accurate timings to be obtained without regard to maximum light of the superoutburst itself.

Title:              Intensive monitoring of OJ 287
Authors:            Pursimo, T.; Takalo, L. O.; Sillanpää, A.;
                    Kidger, M.; Lehto, H. J.; Heidt, J.;
                    Charles, P. A.; Aller, H.; Aller, M.;
                    Beckmann, V.; Benítez, E.; Bock, H.;
                    Boltwood, P.; Borgeest, U.; de Diego, J. A.;
                    De Francesco, G.; Dietrich, M.;
                    Dultzin-Hacyan, D.; Efimov, Y.; Fiorucci, M.;
                    Ghisellini, G.; González-Pérez, N.; Hanski, M.;
                    Heinämäki, P.; Honeycutt, R. K.; Hughes, P.;
                    Karlamaa, K.; Katajainen, S.; Knee, L. B. G.;
                    Kurtanidze, O. M.; Kümmel, M.; Kühl, D.;
                    Lainela, M.; Lanteri, L.; Linde, J. V.;
                    Lähteenmäki, A.; Maesano, M.; Mahoney, T.;
                    Marchenko, S.; Marscher, A.; Massaro, E.;
                    Montagni, F.; Nesci, R.; Nikolashvili, M.;
                    Nilsson, K.; Nurmi, P.; Pietilä, H.;
                    Poyner, G.; Raiteri, C. M.; Rekola, R.;
                    Richter, G. M.; Riehokainen, A.;
                    Robertson, J. W.; Rodríguez-Espinoza, J.-M.;
                    Sadun, A.; Shakhovskoy, N.; Schramm, K. J.;
                    Schramm, T.; Sobrito, G.; Teerikorpi, P.;
                    Teräsranta, H.; Tornikoski, M.; Tosti, G.;
                    Turner, G. W.; Valtaoja, E.; Valtonen, M.;
                    Villata, M.; Wagner, S. J.; Webb, J.;
                    Weneit, W.; Wiren, S.
Affiliation:        AA( Tuorla Observatory, Tuorla, FIN-21500 Piikkiö, 
                    Finland), AB( Tuorla Observatory, Tuorla, FIN-21500 
                    Piikkiö, Finland), AC( Tuorla Observatory, Tuorla, 
                    FIN-21500 Piikkiö, Finland), AD(Instituto de 
                    Astrofísica de Canarias, E-38200 La Laguna, 
                    Tenerife, Spain), AE( Tuorla Observatory, Tuorla, 
                    FIN-21500 Piikkiö, Finland; Department of Physics, 
                    Turku University, FIN-20014, Finland), 
                    AF(Landessternwarte Heidelberg, Königstuhl, D-69117 
                    Heidelberg, Germany), AG(University of Oxford, Dept. 
                    of Astrophysics, Nuclear & Astrophysics laboratory, 
                    Keble Road, Oxford, OX1 3RH, UK), AH(University of 
                    Michigan, Physics and Astronomy, 817 Dennison 
                    Building, Ann Arbor, MI 48109, U.S.A.), 
                    AI(University of Michigan, Physics and Astronomy, 
                    817 Dennison Building, Ann Arbor, MI 48109, U.S.A.), 
                    AJ(Hamburger Sternwarte, Hamburg Universität, 
                    Gojensbergweg 112, D-21029 Hamburg 80, Germany), 
                    AK(Instituto de Astronomia-UNAM, Apto. Postal 
                    70-264, 04510, Mexico, D.F. Mexico), 
                    AL(Landessternwarte Heidelberg, Königstuhl, D-69117 
                    Heidelberg, Germany), AM(1655 main St. Stittsville, 
                    Ont K2S 1N6, Canada), AN(Hamburger Sternwarte, 
                    Hamburg Universität, Gojensbergweg 112, D-21029 
                    Hamburg 80, Germany), AO(Instituto de 
                    Astronomia-UNAM, Apto. Postal 70-264, 04510, Mexico, 
                    D.F. Mexico), AP(Osservatorio Astronomico di Torino, 
                    Strada Osservatorio 20, I-10025 Pino Torinese, 
                    Italy), AQ(Landessternwarte Heidelberg, Königstuhl, 
                    D-69117 Heidelberg, Germany), AR(Instituto de 
                    Astronomia-UNAM, Apto. Postal 70-264, 04510, Mexico, 
                    D.F. Mexico), AS(Crimean Astrophysical Observatory, 
                    P/O Nauchny, 98409 Crimea, Ukraine, Isaak Newton 
                    Institute of Chile, Crimean Branch), AT(Osservatorio 
                    Astronomica, Universitá di Perugia, I-06100 Perugia, 
                    Italy), AU(Osservatorio Astronomico di Brera, Via 
                    Bianchi 46, I-23807 Merate, Italy), AV(Instituto de 
                    Astrofísica de Canarias, E-38200 La Laguna, 
                    Tenerife, Spain), AW( Tuorla Observatory, Tuorla, 
                    FIN-21500 Piikkiö, Finland), AX( Tuorla Observatory, 
                    Tuorla, FIN-21500 Piikkiö, Finland), AY(Department 
                    of Astronomy, Indiana University, Swain West 319, 
                    Bloomington, IN 47405, U.S.A.), AZ(University of 
                    Michigan, Physics and Astronomy, 817 Dennison 
                    Building, Ann Arbor, MI 48109, U.S.A.), BA(Metsähovi 
                    Radio Observatory, Metsähovintie 114, FIN-02450 
                    Kylmälä, Finland), BB( Tuorla Observatory, Tuorla, 
                    FIN-21500 Piikkiö, Finland), BC(National Research 
                    Council Canada, Herzberg Institute of Astrophysics, 
                    Dominion Radio Astrophysical Observatory, P.O. Box 
                    248, Penticton, BC, Canada V2A 6K3, Canada), 
                    BD(Astrophysicalisches Institute Potsdam An der 
                    Sternwaret 16, D-14482 Potsdam, Germany), 
                    BE(Department of Physics, Florida International 
                    University, University Park, Miami, FL 33199, 
                    U.S.A.), BF(Landessternwarte Heidelberg, Königstuhl, 
                    D-69117 Heidelberg, Germany), BG(Hamburger 
                    Sternwarte, Hamburg Universität, Gojensbergweg 112, 
                    D-21029 Hamburg 80, Germany), BH( Tuorla 
                    Observatory, Tuorla, FIN-21500 Piikkiö, Finland; 
                    Department of Physics, Turku University, FIN-20014, 
                    Finland), BI(Osservatorio Astronomico di Torino, 
                    Strada Osservatorio 20, I-10025 Pino Torinese, 
                    Italy), BJ(Hamburger Sternwarte, Hamburg 
                    Universität, Gojensbergweg 112, D-21029 Hamburg 80, 
                    Germany), BK(Metsähovi Radio Observatory, 
                    Metsähovintie 114, FIN-02450 Kylmälä, Finland), 
                    BL(Instituto Astronomico, Universita di Roma ``La 
                    Sapienza'', via G.M. Lancisi, 29, I-00161 Roma, 
                    Italy), BM(Instituto de Astrofísica de Canarias, 
                    E-38200 La Laguna, Tenerife, Spain), BN(Astronomical 
                    Institute of St. Petersburg State University, 198904 
                    St. Petersburg, Russia), BO(Department of Astronomy, 
                    Boston University, 725 Commonwealth Ave. Boston, MA 
                    02215, U.S.A.), BP(Instituto Astronomico, Universita 
                    di Roma ``La Sapienza'', via G.M. Lancisi, 29, 
                    I-00161 Roma, Italy), BQ(Instituto Astronomico, 
                    Universita di Roma ``La Sapienza'', via G.M. 
                    Lancisi, 29, I-00161 Roma, Italy), BR(Instituto 
                    Astronomico, Universita di Roma ``La Sapienza'', via 
                    G.M. Lancisi, 29, I-00161 Roma, Italy), 
                    BS(Abastumani Observatory, 38762 Abastumani, 
                    Republic of Georgia), BT( Tuorla Observatory, 
                    Tuorla, FIN-21500 Piikkiö, Finland), BU( Tuorla 
                    Observatory, Tuorla, FIN-21500 Piikkiö, Finland), 
                    BV( Tuorla Observatory, Tuorla, FIN-21500 Piikkiö, 
                    Finland), BW(The Astronomer Organization, 
                    Birmingham, UK), BX(Osservatorio Astronomico di 
                    Torino, Strada Osservatorio 20, I-10025 Pino 
                    Torinese, Italy), BY( Tuorla Observatory, Tuorla, 
                    FIN-21500 Piikkiö, Finland), BZ(Astrophysicalisches 
                    Institute Potsdam An der Sternwaret 16, D-14482 
                    Potsdam, Germany), CA(Tuorla Observatory, Tuorla, 
                    FIN-21500 Piikkiö, Finland), CB(Department of 
                    Astronomy, Indiana University, Swain West 319, 
                    Bloomington, IN 47405, U.S.A.), CC(Instituto de 
                    Astrofísica de Canarias, E-38200 La Laguna, 
                    Tenerife, Spain), CD(University of Colorado at 
                    Denver, P.O. Box 173364, Denver, CO 80217-3364, 
                    U.S.A.), CE(Crimean Astrophysical Observatory, P/O 
                    Nauchny, 98409 Crimea, Ukraine, Isaak Newton 
                    Institute of Chile, Crimean Branch), CF(Hamburger 
                    Sternwarte, Hamburg Universität, Gojensbergweg 112, 
                    D-21029 Hamburg 80, Germany), CG(Hamburger 
                    Sternwarte, Hamburg Universität, Gojensbergweg 112, 
                    D-21029 Hamburg 80, Germany), CH(Osservatorio 
                    Astronomico di Torino, Strada Osservatorio 20, 
                    I-10025 Pino Torinese, Italy), CI(Tuorla 
                    Observatory, Tuorla, FIN-21500 Piikkiö, Finland), 
                    CJ(Metsähovi Radio Observatory, Metsähovintie 114, 
                    FIN-02450 Kylmälä, Finland), CK(Metsähovi Radio 
                    Observatory, Metsähovintie 114, FIN-02450 Kylmälä, 
                    Finland), CL(Osservatorio Astronomica, Universitá di 
                    Perugia, I-06100 Perugia, Italy), CM(Department of 
                    Astronomy, Indiana University, Swain West 319, 
                    Bloomington, IN 47405, U.S.A.), CN( Tuorla 
                    Observatory, Tuorla, FIN-21500 Piikkiö, Finland; 
                    Department of Physics, Turku University, FIN-20014, 
                    Finland), CO( Tuorla Observatory, Tuorla, FIN-21500 
                    Piikkiö, Finland; Department of Physics, Turku 
                    University, FIN-20014, Finland), CP(Osservatorio 
                    Astronomico di Torino, Strada Osservatorio 20, 
                    I-10025 Pino Torinese, Italy), CQ(Landessternwarte 
                    Heidelberg, Königstuhl, D-69117 Heidelberg, 
                    Germany), CR(Department of Physics, Florida 
                    International University, University Park, Miami, FL 
                    33199, U.S.A.), CS(Hamburger Sternwarte, Hamburg 
                    Universität, Gojensbergweg 112, D-21029 Hamburg 80, 
                    Germany), CT( Tuorla Observatory, Tuorla, FIN-21500 
                    Piikkiö, Finland; Metsähovi Radio Observatory, 
                    Metsähovintie 114, FIN-02450 Kylmälä, Finland)
Publication:        Astronomy and Astrophysics Supplement, v.146, 
                    p.141-155 (A&AS Homepage)
Publication Date:   10/2000
Origin:             A&AS
A&A Keywords:       BL LAC OBJECTS, OJ 287, PHOTOMETRY
Bibliographic Code: 2000A&AS..146..141P

Abstract

We present intensive optical, infrared, and radio monitoring observations of the BL Lac object OJ 287, taken between the years 1993-1998. Two large optical outbursts were detected at the predicted times in November 1994 and December 1995. The detection of these outbursts supports the binary black hole model for OJ 287. Optical and radio polarisation observations show large variability in the degree of polarisation and position angle, very similar to those observed during the 1983/84 outburst in OJ 287. The polarisation position angles show very similar behaviour during these observations, indicating that, at least, the magnetic field orientations in radio and optical bands are related in OJ 287. Optical and infrared light curves show continuous variability in time scales ranging from tens of minutes to years. In the radio bands we have observed some of the lowest ever measured flux levels. During the first optical outburst in November 1994 the observed radio flux was very low, but during the second optical outburst radio bands also showed high flux levels. This is a puzzling observation, which can hopefully be used for discriminating between different outburst models. On top of the large outbursts OJ 287 has displayed flaring activity in time scales from days to weeks and shorter time scale flickering. Based partly on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway and Sweden in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrofísica de Canarias. Based partly on observations collected at the German-Spanish Astronomical Center, Calar Alto, operated by the Max-Planck-Institute für Astronomie, Heidelberg, jointly with the Spanish National Commission for Astronomy. Based partly on observations carried out at Observatorio Astronomico National, San Pedro Martir, Baja California, Mexico. Based partly on observations made with the IAC-80 Telescope and the Carlos Sánchez Telescope operated on the island of Tenerife by the Instituto de Astrofísica de Canarias at the Spanish Observatorio del Teide.

Title:              Post-Common-Envelope Binary Stars and the 
                    Precataclysmic Binary PG 1114+187
Authors:            Hillwig, Todd C.; Honeycutt, R. Kent;
                    Robertson, Jeff W.
Affiliation:        AA(Department of Astronomy, Swain Hall West 319, 
                    Indiana University, Bloomington, IN 47405; 
                    , ), AB(Department of Astronomy, Swain Hall West 319, Indiana University, Bloomington, IN 47405; , ), AC(Department of Physical Sciences, Arkansas Tech University, Russellville, AR 72801-2222 ) 

Publication:        The Astronomical Journal, Volume 120, Issue 2, pp. 
                    1113-1119. (AJ Homepage)
Publication Date:   08/2000
Origin:             UCP
AJ Keywords:        Stars: Binaries: Close, stars: individual (PG 
                    1114+187)
Abstract Copyright: (c) 2000: The American Astronomical Society
DOI:                10.1086/301479
Bibliographic Code: 2000AJ....120.1113H

Abstract

We present orbit-resolved spectroscopy and orbit-sampled photometry of the binary system PG 1114+187. Both photometry and radial velocity studies reveal a period P=1.75992 days, which is taken to be the orbital period of the binary. Strong modulation of emission-line strength with the same period is also present. A preliminary mass ratio, M₂/M₁~0.7, is found from primary- and secondary-star radial velocity amplitudes. No evidence is seen for either an accretion disk or mass transfer, leading to the conclusion that PG 1114+187 is not a cataclysmic variable (CV) but is in a pre-CV state, before the initiation of mass transfer. The short orbital period also leads to the conclusion that the system passed through a common-envelope phase at some time in the past. The current list of known post-common-envelope and precataclysmic binary stars is also reviewed and the general properties of this class of star are discussed.

Title:              Reconnaissance of Suspected Old Novae
Authors:            Robertson, Jeff W.; Honeycutt, R. K.;
                    Hillwig, T.; Jurcevic, J. S.; Henden, A. A.
Affiliation:        AA(Department of Physical Sciences, Arkansas Tech 
                    University, Russellville, AR 72801-2222 
                    ), AB(Department of Astronomy, Swain West 319, Indiana University, Bloomington, IN 47405; ), AC(Department of Astronomy, Swain West 319, Indiana University, Bloomington, IN 47405; ), AD(Department of Astronomy, RLM 15.308, University of Texas, Austin, TX 78712; ), AE(US Naval Observatory, Flagstaff Station, P.O. Box 1149, Flagstaff, AZ 86002; ) 

Publication:        The Astronomical Journal, Volume 119, Issue 3, pp. 
                    1365-1374. (AJ Homepage)
Publication Date:   03/2000
Origin:             UCP
AJ Keywords:        STARS: NOVAE, CATACLYSMIC VARIABLES
Abstract Copyright: (c) 2000: The American Astronomical Society
DOI:                10.1086/301250
Bibliographic Code: 2000AJ....119.1365R

Abstract

Several of the ``blank fields'' in the novae atlas by Duerbeck were imaged at the WIYN 3.5 m telescope during technical engineering and commissioning activities in 1994-1995. Several old novae have been recovered utilizing CCD photometry. Multiobject spectroscopy with the Hydra/MOS instrumentation at WIYN was also used on random stars in the fields to search for a cataclysmic variable. The old novae candidates identified include SV Ari, V465 Cyg, SS LMi, V2104 Oph, GR Ori, V529 Ori, UW Per, and UW Tri.

Title:              Reconnaissance of Suspected Old Novae
Authors:            Robertson, J. W.; Honeycutt, R. K.; Henden, A. H.
Affiliation:        AA(Arkansas Tech University), AB(Indiana 
                    University), AC(U.S. Naval Observatory)
Publication:        American Astronomical Society Meeting 194, #115.04
Publication Date:   09/1999
Origin:             AAS
Abstract Copyright: (c) 1999: American Astronomical Society
Bibliographic Code: 1999AAS...19411504R

Abstract

Several of the ``blank fields'' in the novae atlas by Duerbeck (1987) were imaged at the WIYN 3.5-m telescope during technical engineering and commissioning activites in 1994-95. Several old novae have been recovered utilizing CCD photometry. Multi-object spectroscopy with the Hydra/MOS instrumentation at WIYN was also used on stars in the fields to search for the spectroscopic signatures of cataclysmic variables. The old novae candidates identified include SV Ari, V465 Cyg, SS LMi, V2104 Oph, GR Ori, V529 Ori, UW Per, and UW Tri.

Title:              The 65 Day Period in 3C 66A during Bright State
Authors:            Lainela, M.; Takalo, L. O.; Sillanpää, A.;
                    Pursimo, T.; Nilsson, K.; Katajainen, S.;
                    Tosti, G.; Fiorucci, M.; Luciani, M.;
                    Villata, M.; Raiteri, C. M.; de Francesco, G.;
                    Sobrito, G.; Benítez, E.; Dultzin-Hacyan, D.;
                    de Diego, J. A.; Turner, G. W.;
                    Robertson, J. W.; Honeycutt, R. K.
Publication:        The Astrophysical Journal, Volume 521, Issue 2, pp. 
                    561-564. (ApJ Homepage)
Publication Date:   08/1999
Origin:             APJ
ApJ Keywords:       GALAXIES: ACTIVE, GALAXIES: INDIVIDUAL (3C 66A), 
                    GALAXIES: PHOTOMETRY
Abstract Copyright: (c) 1999: The American Astronomical Society
DOI:                10.1086/307599
Bibliographic Code: 1999ApJ...521..561L

Abstract

Historically, 3C 66A has been considered a relative quiescent blazar. For that reason, 3C 66A was selected as a comparison source for OJ 287 in the OJ-94 project. However, after more detailed observation it turns out that the variability of 3C 66A itself is very interesting. We have analyzed the entire project data set of 3C 66A from fall of 1993 to spring of 1998 by using structure function analysis, Deeming periodograms, Scargle periodograms, and the folded light curves. Here we present the first preliminary evidence for the 65 day period in 3C 66A observed during the bright state. Our analysis indicates that this period is slowly slowing down. We will also discuss the possible physical mechanism producing the observed periodicity.

Title:              RXTE, ROSAT, EUVE, IUE, and Optical Observations 
                    through the 45 Day Supercycle of V1159 Orionis
Authors:            Szkody, Paula; Linnell, A.; Honeycutt, Kent;
                    Robertson, Jeff; Silber, Andrew; Hoard, D. W.;
                    Pastwick, L.; Desai, V.; Hubeny, Ivan;
                    Cannizzo, John; Liller, William;
                    Zissell, Ronald; Walker, Gary
Publication:        The Astrophysical Journal, Volume 521, Issue 1, pp. 
                    362-375. (ApJ Homepage)
Publication Date:   08/1999
Origin:             APJ
ApJ Keywords:       STARS: NOVAE, CATACLYSMIC VARIABLES, STARS: 
                    INDIVIDUAL: CONSTELLATION NAME: V1159 ORIONIS, 
                    ULTRAVIOLET: STARS, X-RAYS: STARS
Abstract Copyright: (c) 1999: The American Astronomical Society
DOI:                10.1086/307550
Bibliographic Code: 1999ApJ...521..362S

Abstract

A complete 45 day supercycle of the cataclysmic variable V1159 Ori comprising a superoutburst and eight normal outbursts was observed. Coverage included ground-based optical observations as well as observations with RXTE for 38 days, ROSAT for 34 days, IUE for 27 days, and Extreme Ultraviolet Explorer (EUVE) for 10 days. The resulting light curves reveal that the optical and UV light variations are inversely correlated with the RXTE and ROSAT fluxes, with the largest change in intensity occurring in the ROSAT bandpass. There is no evidence for a strong EUV/soft X-ray component during outburst. An outflowing wind is evident from the C IV line profile during each brief outburst as well as the superoutburst. The transitions from outburst states of the disk to quiescent states take place on timescales of hours. Accretion disk models can fit the UV line and continuum energy distributions near outburst only if the disk radial temperature profile is modified from the standard case to produce a hotter distribution in the outer annuli. The high mass transfer rate, the hot disk distribution, and the similarity of outbursts and superoutbursts argue for outside-in outbursts in this system.

Title:              Multiyear Photometry and a Spectroscopic Orbital 
                    Period Search for the VY SCULPTORIS Type Cataclysmic 
                    Variable V794 Aquilae
Authors:            Honeycutt, R. K.; Robertson, J. W.
Affiliation:        AA(Department of Astronomy, Indiana University, 
                    Swain Hall West, Bloomington, IN 47405; 
                    , ), AB(Department of Astronomy, Indiana University, Swain Hall West, Bloomington, IN 47405; , ) 

Publication:        The Astronomical Journal, Volume 116, Issue 4, pp. 
                    1961-1965. (AJ Homepage)
Publication Date:   10/1998
Origin:             AJ
AJ Keywords:        STARS: NOVAE, CATACLYSMIC VARIABLES, STARS: 
                    INDIVIDUAL: CONSTELLATION NAME: V794 AQUILAE
DOI:                10.1086/300539
Bibliographic Code: 1998AJ....116.1961H

Abstract

Continued photometry of the nova-like cataclysmic variable (CV) V794 Aql shows that the unusual repetitive, slow, deep declines that were reported earlier for 1990-1992 have persisted now for over 6 years. The slow declines and rapid rises are shown to have relatively consistent shapes. This continued behavior presents some potential problems for the model of Honeycutt, Cannizzo, & Robertson, in which the ``sawtooth''-shaped light curve was considered to be an accretion disk instability initiated as M dropped from the nova-like regime. Alternative mechanisms are briefly explored and are argued to also encounter difficulties in accounting for the light curve. A radial velocity study of V794 Aql yields a best period of 0.1533 days (3.68 hr). Periods of 0.1336 and 0.1787 days are considerably less likely but cannot be ruled out from the data at hand. These periods are in the expected range for VY Sculptoris type nova-like CVs.

Title:              Medium-resolution echelle spectrograph design
Authors:            Honeycutt, R. K.; Robertson, Jeff W.; Pier, Jeff R.
Affiliation:        AA(Indiana Univ.), AB(U.S. Naval Observatory)
Publication:        Proc. SPIE Vol. 3355, p. 696-702, Optical 
                    Astronomical Instrumentation, Sandro D'Odorico; Ed. 
                    (SPIE Homepage)
Publication Date:   07/1998
Origin:             SPIE
Abstract Copyright: (c) 1998 SPIE--The International Society for Optical 
                    Engineering. Downloading of the abstract is 
                    permitted for personal use only.
Bibliographic Code: 1998SPIE.3355..696H

Abstract

Time-resolved spectroscopic studies of relatively faint stars that vary on many time scales, such as interacting binary stars, benefit from a particular combination of wide wavelength coverage, medium spectral resolution, and high efficiency. We describe two similar fiber-fed echelle spectrograph designs that address this need, with an emphasis on eventual use for automated, unattended spectroscopy. The coverage is approximately 385 - 850 nm in about 25 echelle orders or approximately 350 - 500 nm in about 16 orders, each with a resolution of about 5000. Cross dispersion is supplied by two prisms in series and the collimator is an off-axis paraboloid. One of the designs incorporates white pupil optics to minimize camera vignetting in the red echelle orders.

Title:              Are Z Camelopardalis-Type Dwarf Novae Brighter at 
                    Standstill?
Authors:            Honeycutt, R. K.; Robertson, J. W.;
                    Turner, G. W.; Mattei, J. A.
Affiliation:        AA(Astronomy Department, Indiana University, Swain 
                    Hall West, Bloomington, IN 47405; 
                    , , ), AB(Astronomy Department, Indiana University, Swain Hall West, Bloomington, IN 47405; , , ), AC(Astronomy Department, Indiana University, Swai!
 n Hall West, Bloomington, IN 47405; , , ), AD(American Association of Variable Star Observers, 25 Birch Street, Cambridge, MA 02138-1205 ) 

Publication:        The Publications of the Astronomical Society of the 
                    Pacific, Volume 110, Issue 748, pp. 676-688. (PASP 
                    Homepage)
Publication Date:   06/1998
Origin:             PASP
PASP Keywords:      STARS: NOVAE, CATACLYSMIC VARIABLES, STARS: 
                    INDIVIDUAL: CONSTELLATION NAME: Z CAMELOPARDALIS, 
                    STARS: INDIVIDUAL (AH HERCULIS), STARS: INDIVIDUAL 
                    (HX PEGASI), STARS: INDIVIDUAL (SY CANCERI), STARS: 
                    INDIVIDUAL: CONSTELLATION NAME: RX ANDROMEDAE
Bibliographic Code: 1998PASP..110..676H

Abstract

Average V-band brightnesses over multiple outbursting and standstill intervals are computed for the light curves of five Z Cam-type dwarf novae: RX And, Z Cam, SY Cnc, AH Her, and HX Peg. Both CCD photometry from RoboScope and AAVSO visual estimates are used in the analysis, with consistent results from the two databases for the stars in common. In four of the five stars, the standstills are as bright as or brighter than the mean V-band brightness during outbursting intervals. This is consistent with Z Cam stars being near the upper stability boundary in M for operation of the thermal limit cycle that is thought to be responsible for dwarf nova outbursts. However, the unusual standstills or hesitations observed in SY Cnc are sometimes fainter than the mean brightness during outbursting intervals. From several well-observed examples we describe the light curves of Z Cam stars as they enter standstill. During this characteristic damped oscillation the amplitude decreases with a timescale approximately equal to the mean outburst recurrence interval, and the period of the oscillation decreases with P&d2 ~=-0.4 as standstill is approached. The exits from standstill usually change abruptly into outbursting mode by emerging from standstill into a decline from outburst.

Title:              Unusual ``Stunted'' Outbursts in Old Novae and 
                    Nova-Like Cataclysmic Variables
Authors:            Honeycutt, R. K.; Robertson, J. W.; Turner, G. W.
Affiliation:        AA(Department of Astronomy, Indiana University, 
                    Swain Hall West, Bloomington, IN 47405; 
                    , , ), AB(Department of Astronomy, Indiana University, Swain Hall West, Bloomington, IN 47405; , , ), AC(Department of Astronomy, Indiana University!
 , Swain Hall West, Bloomington, IN 47405; , , ) 

Publication:        The Astronomical Journal, Volume 115, Issue 6, pp. 
                    2527-2538. (AJ Homepage)
Publication Date:   06/1998
Origin:             AJ
AJ Keywords:        STARS: NOVAE, CATACLYSMIC VARIABLES, STARS: 
                    INDIVIDUAL: CONSTELLATION NAME: UU AQUARII, STARS: 
                    INDIVIDUAL (Q CYGNI, CP LACERTAE), STARS: 
                    INDIVIDUAL: CONSTELLATION NAME: X SERPENTIS, STARS: 
                    INDIVIDUAL: CONSTELLATION NAME: RW SEXTANTIS
Abstract Copyright: The American Astronomical Society
DOI:                10.1086/300381
Bibliographic Code: 1998AJ....115.2527H

Abstract

Outbursts averaging 0.6 mag in amplitude and 10 days in width are described in five old novae and nova-like cataclysmic variables: UU Aqr, Q Cyg, CP Lac, X Ser, and RW Sex. These stars are thought to be high mass transfer rate systems for which the accretion disk is expected to be stable against the thermal instability responsible for dwarf nova outbursts. The widths and spacings of these events are similar to those of dwarf nova eruptions, but the amplitudes are significantly smaller, or ``stunted.'' The outbursts are sometimes accompanied by dips. These dips have amplitudes that are similar to the outbursts' but have shapes that scatter significantly more than the shapes of the outbursts. The outbursts and dips sometimes occur as pairs and are sometimes isolated. We are not able at this time to determine a single common mechanism for this behavior, or even to conclude that some mechanisms are preferred. Rather, we characterize these phenomena with regard to outburst shapes and frequency of occurrence and explore a range of possible causes, including truncated disks, mass transfer modulations, and Z Camelopardalis type behavior. Arguments are assembled for and against such possible mechanisms, and key observations are suggested. It appears unlikely that accretion disk instabilities are the single common cause of these phenomena, and we are left with either a combination of accretion disk and mass transfer events or a situation in which mass transfer events are somehow responsible for all these varied behaviors.

Title:              Spectroscopic and Photometric Analysis of the