CV News

Special Notice #381: HST/COS observations of SDSS J100658.40+233724.4

March 5, 2014: HST/COS are being scheduled for the U Gem-type dwarf nova SDSS J100658.40+233724.4, the 40th and final target of the major CV observing campaign organized in 2012 by Drs. Boris Gaensicke, Joseph Patterson, Arne Henden, and 13 other astronomers (see AAVSO Alert Notice 471 and note below). A precise time will be announced later, but the scheduled HST observing window is:

SDSS J100658.40+233724.4  2014 Mar. 20 or 21 UT (to be determined)

Please observe SDSS J100658.40+233724.4 closely through the end of March. AAVSO observations show SDSS J100658.40+233724.4, usually around 18.3 V at minimum, can be as faint as magnitude 20.02 V (LSTA, S. Littlefair, Sheffield, England) and as bright as 15.662 V at maximum (GFB, W. Goff, Sutter Creek, CA).

Coordinates (2000.0):
SDSS J100658.40+233724.4   R.A. 10 06 58.42  Dec. +23 37 24.6

Charts may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp).

Please report observations as soon as possible to the AAVSO International Database using the name SDSS J100658.40+233724.4. If an outburst is detected, please report observations immediately. Many thanks!

Details of the HST/COS CV campaign and specific observing instructions may be found in AAVSO Alert Notice 471 (http://www.aavso.org/aavso-alert-notice-471). Related AAVSO Special Notices may be found via the Observing Campaigns page (http://www.aavso.org/observing-campaigns). AAVSO Special Notice #371(http://www.aavso.org/aavso-special-notice-371) is the most recent one that pertains to the campaign.

AAVSO observers have played a crucial role in this campaign from the beginning, and good coverage of this last target is equally important. Thank you for your valuable contributions!

This AAVSO Special Notice was compiled by Elizabeth O. Waagen.

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CV Zoo

Prime CV specimens-

U Gem

This variable is the typical star of its class and was the first to be discovered. J.R. Hind, an English astronomer in charge of a private observatory in Regents Park, found a previously unlisted star in the constellation Gemini to be nearly 9th magnitude on December 15, 1855.

SS Cyg

Since its discovery in 1896 by Louisa D. Wells of the Harvard College Observatory, SS Cygni has undoubtedly been one of the most observed variable stars in the night sky.

SU UMa

Discovered in 1908 by L. Ceraski of Moscow, the variable SU Ursae Majoris is the prototype for variables belonging to this subtype of dwarf novae.

Z Cam

Z Camelopardalis is the prototype star of a subclass of dwarf nova-type cataclysmic variables especially known for their random standstills.

WZ Sge

WZ Sge - the prototype of the WZ Sge subclass of dwarf nova cataclysmic variables - went into a rare outburst on July 23, 2001, captivating the attention of amateur and professional astronomers around the globe.

AM Her

The exotic star AM Herculis is the namesake of the “AM Her stars” or “polars”, a unique class of cataclysmic variables in which the magnetic field of the primary star (white dwarf) completely dominates the accretion flow of the system.







Some other interesting beasts-

RX And

Since its discovery in 1905, RX And has undergone nearly every type of behavior seen in the dwarf novae, creating one of the more interesting light curves among the CVs.

IP Peg

IP Pegasi is an eclipsing binary system with a long orbital period (3.80 hours) that shows evidence of spiral arms in its accretion disc.

RS Oph

Over a century of observations shows that this recurrent nova has undergone 6 recorded outbursts: 1898, 1933, 1958, 1967, 1985 and the most recent one in 2006.

T Pyx

This star is way overdue for an outburst and when it happens, some people think it is going to be a big one.

VW Hyi

VW Hyi is one of the most popular dwarf novae in the southern skies.

GK Per

Once GK Per's magnetic nature was discovered, it was classified based on the strength of the white dwarf's magnetic field into the cataclysmic variable subtype, intermediate polar or DQ Her star.