MACHO 311.37557.169-- A southern hemisphere VY Scl star

Fri, 09/27/2019 - 13:20

Hello obervers,

I am asking for V-band observations of the southern hemisphere variable star MACHO 311.37557.169, which we believe to be a VY Scl star (RA 18 18 41.7, DEC -23 56 21.1)

We already have an XMM-Newton observation of the object, as well as an archival optical spectrum and the long term MACHO survey light curves. The paper, to be published in Astronomische Nachrichten, is almost finished but the referee has asked for optical observations to obtain the following:

* Flickering on ~15 minute timescales characteristic to these sources,

* Orbital and/or hump modulation on timescales of a few hours

 

The source is about 16th magnitude, so within reach for 30-40cm scopes at 60s exposures. We would need two to three half nights of observations. Naturally, you will be listed as a coauthor on the paper.

 

Thanks,

Hauke.

 

 

 

finding charts:

https://imgur.com/M9ioE2j

https://imgur.com/p0iPjiV