CVNET

Cataclysmic Variables Network

ACTIVITY AT A GLANCE

Last updated 07:38 UT on 21 October 2021

(All objects mentioned this section are in the International Variable Star Index; additionally, VSX links have been given for selected cataclysmic variables)

'Activity at a Glance' is gleaned from observations reported to AAVSO MyNewsFlash, BAAVSS-Alert, CVnet-Outburst, VSObs-share and VSNET-outburst. We sincerely thank all the observers who contribute timely observations and reports of activity to these email lists.


New outbursts and unusual activity reported in the last 72 hours

YYYYMMDD


20211020

1RXS J063214.8+253620 #


Current superoutbursts (since ...)
SDSS J203501.46-001946.1 :* (20210927, UGSU:)
MASTER OT J055845.55+391533.4 * (20210923, UGSU)
ASASSN-16og : (20210921, UGSU)
LL And #* (20210912, UGWZ)
ASASSN-19ax
:* (20210910, UGSU:)
MASTER OT J055845.55+391533.4 (20210909, UGSU)
NY Her (20210828, UGSU)
V493 Lyr : (20210828, UG)
V1024 Per (20210827, UGSU)
GV Psc (20210827, UGSU)
OT J215818.5+241925 * (20210827, UGSU)
SDSS J172102.48+273301.2 #* (20210826, AM CVn star)
ASASSN-21nv :# (20210727, UGWZ:)

V627 Peg #* (20210715, UGWZ)

Z Cam-type dwarf novae at standstill
Z Cam ends long 1,051 day standstill on 20210828 (started on 20181012)


# indicates a noteworthy or unusual activity

: indicates confirmation required
*
indicates time-resolved photometry required











CV News

LL Andromedae

From BAAVSS-Alert, 16 September 2021


The large amplitude dwarf nova, LL And, was reported to be in outburst by the undersigned at magnitude 12.8 (CCD, clear filter) on September 14.902.

Subsequent time series photometry by Tamas Tordai, the Kyoto University team and the Director has revealed small humps in the light curve, but these do not appear to be related to the orbital period (Porb = 79 mins). It is anticipated that full blown superhumps may appear in the next few days. Follow up observations, both time series photometry and individual data points, are therefore urgently requested. Spectroscopy is also welcome, especially considering that the object is so bright – a spectrum taken on the first night by Robin Leadbeater, showing H-Balmer lines in absorption, is presented on the BAA Forum: https://britastro.org/node/26220

LL And is a member of the WZ Sge family of dwarf novae which show large amplitude outbursts at very long intervals. In quiescence, LL And is mag 20, so its amplitude is ca. 7 magnitudes. LL And was seen in outburst in December 1993, and the last confirmed outburst occurred in December 2008. One other outburst was observed in June 2004.

LL And is conveniently located at RA 00 41 51.47 DEC +26 37 21.1 (J2000.0) and is visible all night. An AAVSO chart, which can readily be scaled and orientated for convenience, can be downloaded here: https://app.aavso.org/vsp/chart/?east=right&fov=30.0&scale=E&star=LL+And&orientation=visual&maglimit=16.5&resolution=150&P=on&north=down&Z=on&type=chart

Please submit observations to the VSS photometry or spectroscopy database. Keep an eye on the BAA Forum for further developments of this unfolding story.

Jeremy Shears

Director, Variable Star Section


AAVSO Alert Notice 754

Monitoring requsted for 15 VY Scl CV's in support of HST observations.

14 September 2021


AAVSO Alert Notice 753

Monitoring requested for seven intermediate polars

23 August 2021


RECENT PAPERS ON CVs

For new papers on CV's see arxiv.org astro-ph


Updated 19 August 2021



The 2019 outburst of the 2005 classical nova V1047 Cen: a record breaking dwarf nova outburst or a new phenomenon?

E. Aydi, K. V. Sokolovsky, J. S. Bright, E. Tremou, M. M. Nyamai, A. Evans, J. Strader, L. Chomiuk, G. Myers, F-J. Hambsch, K. L. Page, D. A. H. Buckley, C. E. Woodward, F. M. Walter, P. Mróz, P. J. Vallely, T. R. Geballe, D. P. K. Banerjee, R. D. Gehrz, R. P. Fender, M. Gromadzki, A. Kawash, C. Knigge, K. Mukai, U. Munari, M. Orio, V. A. R. M. Ribeiro, J. L. Sokoloski, S. Starrfield, A. Udalski, P. A. Woudt


MGAB-V859 and ZTF18abgjsdg: ER UMa-type dwarf novae showing standstills

Taichi Kato, Naoto Kojiguchi (Kyoto U)


The role of complex ionized absorber in the soft X-ray spectra of Intermediate Polars

Nazma Islam, Koji Mukai


The Detailed Light Curve Evolution of V1674 Her (Nova Her 2021)

R. M. Quimby, A. W. Shafter, H. Corbett


The intermediate polar cataclysmic variable GK Persei 120 years after the nova explosion: a first dynamical mass study

A. Álvarez-Hernández (1,2), M. A. P. Torres (1,2), P. Rodríguez-Gil (1,2), T. Shahbaz (1,2), G. C. Anupama (3), K. D. Gazeas (4), M. Pavana (3,5), A. Raj (6), P. Hakala (7), G. Stone (8), S. Gomez (9), P. G. Jonker (10,11), J.-J. Ren (12), G. Cannizzaro (10,11), I. Pastor-Marazuela (13,14), W. Goff (15), J. M. Corral-Santana (16), R. Sabo (17) ((1) Instituto de Astrofísica de Canarias, (2) Departamento de Astrofísica, Universidad de La Laguna, (3) Indian Institute of Astrophysics, (4) Section of Astrophysics, Astronomy and Mechanics, Department of Physics, National and Kapodistrian University of Athens, (5) Department of Physics, Pondicherry University, (6) Dept. of Physics & Astrophysics, University Road, University Enclave, (7) Finnish Centre for Astronomy with ESO (FINCA), Quantum, University of Turku, (8) First Light Observatory Systems, (9) Center for Astrophysics | Harvard & Smithsonian, (10) SRON, Netherlands Institute for Space Research, (11) Department of Astrophysics / IMAPP, Radboud University, (12) CAS Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, (13) Anton Pannekoek Institute, University of Amsterdam, (14) ASTRON, the Netherlands Institute for Radio Astronomy, (15) American Association of Variable Star Observers, (16) European Southern Observatory, (17) American Association of Variable Star Observers)





CV artwork courtesy Darren Baskill