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HDE 269006

paw
paw's picture
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Joined: 2010-08-07

I still get 9.0 vis. Problem somewhere?

Alan (paw)

LMC V0733 brightening
Sebastian Otero
Sebastian Otero's picture
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Joined: 2010-09-19

Hi, Alan,

We don't how how long this brightening was (or is). According to the compiled V-photometry of the star, the SDOR phases develope slowly:
http://www.aavso.org/vsx/docs/235103/133/HD269006_history.gif
http://www.aavso.org/vsx/docs/235103/133/HD269006_recent.gif

But this event is huge, the star is by far the brightest star in the LMC now.
Does someone know of any other star that has been this bright excepting SN 1987A?

I wouldn't expect the star to fade so quickly to 9.0 but who knows.

It is interesting to note that -as always happens with SDOR phases-, the star moves to the right in the H-R diagram when it gets bright, so it gets redder (luminosity remains constant but the radiation peak gets closer to the visual wavelength).
At minimum it is a B2.5 supergiant with a B-V around 0.02 while these excursions to the red side of the H-R had taken it to the F0 spectral type (B-V 0.45) in 2009 and now it is reported to have an early G spectral type. The latest B-V from AAVSO data was +0.66, right at the beginning of this rapid brightening. So it is very likely that the star is even redder than 0.7 now. I don't think it is a color problem but the emission lines in its spectrum may be playing a role here: I find my eta Car estimates slightly fainter than V due to this reason.

We'll definitely know when more observations (of all kinds) are reported.

Cheers,
Sebastian

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484