V576 Carinae April 21, 2008

Michael Sallman brought this variable to the attention of the AAVSO during a recent Chatroom discussion (if you haven't tried AAVSO Chat, you should. It is one of the easiest ways to talk to the Director, and there are often interesting astronomy topics). V576 Car (AUID 000-BFQ-470) is located at:

08:19:15.71 -60:10:00.6 (J2000) (proper motion 136mas/yr in RA and -22mas/yr in Dec, so moving pretty rapidly to the east)

A paper by Couch, Lloyd Evans and Sarre 2003MNRAS.346..153C indicate that this star is an infrared source (IRAS 08182-6000), and at the time of the paper, had been increasing in brightness for over a decade. They classified it as a post-AGB star surrounded by cool dust. The ASAS light curve supports a continued brightness increase:

http://www.astrouw.edu.pl/cgi-asas/asas_variable/081916-6010.0, asas3, 0.0, 2000.0000, 370, 270

where it is shown that the star has increased from V=11.8 to its current V=10.2 in about 7 years. This is reminiscent of FG Sge, which also consistently increased in brightness during its fast evolution through the upper part of the Hertzsprung-Russell Diagram.

Laszlo Kiss and Arne Henden would like to initiate a monitoring campaign for this object at all wavelengths. No time series to look for quasi-periodic oscillations have been acquired; no recent spectra are available; no obvious non-photographic deep image is available. We would suggest that a couple of observers do some time series photometry, but everyone keep it on their observing program, observing it nightly at in at least V-band; use the full UBVRI set if possible. Those with spectroscopic capability should acquire a spectra about once/week.

Thanks to Mati Morel, a chart with comparison/sequence stars is available through VSP. Arne

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