S Doradus, anybody?

[bojan]

Anybody watching this?

*********************************** ****
AAVSO Special Notice #205

Rapid fading in the luminous blue variable S Doradus
April 15, 2010

Noel D. Richardson and Douglas R. Gies (Georgia State University)
announced on 2010 April 14 (Astronomer's Telegram #2560) that S Doradus
is currently fading in optical brightness, while its hydrogen Balmer
line (H-alpha) brightness is increasing. The V-band magnitude of S Dor
(as measured by ASAS-3; Pojmanski, G., 2002, AcA 52, 397) has been
declining for more than a thousand days. The star began a more rapid
decline earlier this year, and is now fainter than V=9.5. BVRI
photometry by G. Di Scala (Sydney, NSW, Australia) shows that the star
was at V=9.83 on 2010 March 08.4535 (JD 2455263.9535), and the most
recent visual observation (A. Plummer, Linden, NSW, Australia) put the
star at m(vis)=9.9 on April 08.4215 (JD 2455294.9215). Observations of
S Dor are encouraged to follow this current event.

S Dor is the class prototype for the luminous blue variables,
supermassive stars that exhibit irregular photometric variability, and
are experiencing substantial mass loss. All observations of S Dor --
both visual estimates and CCD photometry -- will be important for
studying the current event. Intensive CCD time-series observations are
not critically needed, but nightly photometry will be very useful.


S Dor is located in the Large Magellanic Cloud, at the following (J2000)
coordinates:

RA: 05 18 14.35 , Dec: -69 15 01.1


Charts for S Dor may be plotted using AAVSO VSP:

http://www.aavso.org/observing/charts/vsp/index.html?pickname=S%20Dor


Please promptly report all observations to the AAVSO using the name
"S DOR".


This AAVSO Special Notice was prepared by Dr. Matthew Templeton

[Rob_K]

Thanks Bojan! Funnily enough, I've started photographically monitoring a star quite close to S Dor, and it managed to scrape in on some of my shots. Can't tell anything from these as presented, but position might be useful for anyone wanting to have a go. Main image is from shot of LMC taken 8 April at 55mm in Canon 400D, insets at right are crops from two images taken at 200mm.

Needs care, because there is a very close star that would have increasing influence at this scale as S Dor dims off. One for long fl monitoring.

Are you going to watch it?

Cheers -

Rob

[Terry B]

I've only been imaging R71 regularly but will start on S Dor as well as they are only a few degrees apart.

[bojan]

I was just starting modification of my EQ6 (used for MTO 1000mm), and EQ3 is good for only 200mm FL. However, I will give it a try..