[vsnet-alert 8817] URGENT= NSV 18024 Spectra an photometry needed

[Sebastian Otero]

Another NSV 19448-like system??

And also in the Southern sky in the constellation Vela.
NSV 18024 = HD 74771 is in outburst.
Position: 08 44 34.05 -37 57 52.5 (2000.0)

URGENT=  outbursts last only a little bit more than 2 weeks for this one and 
it started 5 days ago.
We have less than 12 days to do something.

This star was found to be another peculiar object back in August while 
checking the NSV catalogue against ASAS-3 data.
It is classified as a G8-K0 star (G8IV/VCNIII in some sources).

Check out the current outburst in ASAS-3 data:
http://www.astrouw.edu.pl/cgi-asas/asas_lc/084434-3757.9

The quasi-period this time was near 490 days but as in the case of NSV 
19448, the current outburst came up early: 290 days after the last one.
Hipparcos caught 3 events and ASAS has now caught 4. Seven outbursts to 
speak of then and all of them are very similar
lasting around 17 days and with a very symmetric shape. Small scatter, the 
extreme infrared brightness that the mira should have to affect the results 
at tha 8th mag. level in V, and the narrowness of the brightenings almost 
exclude the background mira possibility again. Maybe a CV then?
Amplitude is between 0.1 and 0.2 mag. and the star goes from its quiescent 
V= 8.13 level up to 7.95 - 8.0.

Cheers,
Sebastian.