Epsilon Aurigae

Take a look at this poster that was presented at the most recent AAS meeting: "Long-Term Optical and Near-Infrared Spectroscopic Monitoring of epsilon Aurigea During the 2009-11 Eclipse"  Our data are even used in one of the figures!!

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     Now that the eclipse of 2009-2011 has ended, we can begin to reflect on the discoveries and realizations made possible by the new data.  To see where we are going, let's reflect on some more of the story leading up to the present.Read more

Check out a new light curve we have posted that contains all your data submitted since the start of the campaign!

As 2011 dwindles down to a close, so does any spectroscopic evidence for the eclipse.  Photometrically, the star returned to its 'normal' out of eclipse variations during late summer, featuring +/- 0.05 mag quasi-periodic fluctuations.

It's been a trail of discovery during 2009-2011, and study of the results will go on for years, but during the next few months, reviewing and updating early statements and claims seems appropriate.

Epsilon Aurigae has fascinated astronomers for parts of three centuries -- so far. The NASA Astrophysical Database Service keeps track of publications related to stars like this one. For the period prior to 1930, 23 papers are on record; for 1930-1960, 54 papers appeared, for 1961-1990 there were 200 papers, reflecting the explosion of interest surrounding the 1983 eclipse (with 173 of those during 1981-1990); more recently (1991-2011) there have been many dozens of papers, thus far.Read more

Greetings.  Winter is nigh, and epsilon Aurigae is fast becoming part of the evening sky, making observing easy - except for the cold conditions.
While the photometric eclipse ended this summer, there remain spectroscopic traces of material from the disk still between us and the F star.  These remnants can be seen in the H-alpha and sodium D lines, as well as in the neutral potassium line far in the red.
Large telescope observations are continuing, and so should your visual and photometric reports.  Remote and robotic observations during November include:
CHARA+MIRC interferometric imaging (Nov.2nd);
MIRAC4 mid-IR spectroscopy (Nov.5th)
Spitzer IRAC near-IR photometry (Nov.17th)
IRTF/SpeX near-IR spectroscopy (Nov.27th)
and more in December.
In the coming weeks, I'll detail some of the recent findings, but you can read results of SpeX data newly published in the Astronomical Journal, at weblink:Read more

Robin Leadbeater, Three Hills Observatory in northern Britain, has assembled a master list of quite a few spectra obtained during the epsilon Aurigae campaign, many with direct access available.  For details see:
http://www.threehillsobservatory.co.uk/epsaur_spectra.htm
We are encouraging Robin and all the contributors to work up summaries of their results for the JAAVSO special issue on epsilon Aurigae, scheduled for early next year.
Meanwhile, do have a look at zeta Aur eclipsing during November - see Brian's blog entry and my comment thereupon.

Dr. Jan Budaj has published an alternative disk model (using your observations!) that explains the mid eclipse brightening without the need for a hole in the disk. He has written an explanation of the new model. Click here to read it in our forums.

I thought I would issue a plug for a talk I'm giving shortly.  On this Thursday, July 28 at 8:00 PM I will be presenting a talk on epsilon Auriage and Citizen Science at Nebraska Nature and Visitor's Center during the Platte Valley Astronomical Observers's monthly meeting.  Weather permitting, we'll also have an observing session afterward.  So, if you happen to be somewhere nearby we'd be happy to have you attend.

About a month ago I wrote a post discussing what I'm doing with some astrometric data from the Sproul Observatory. This week I'm happy to report I have the paper almost entirely written and am working out the last few kinks in the analysis. It's been a serious uphill battle in both learning about astrometry and reducing the data, but I think it's been worth it.

In this post I'm going to talk a little more about the data and how it is reduced. In the prior post I mentioned that the data was taken on photographic plates starting in 1938 and ending in the early 1980s. I only have a small subset of the entire set from Sproul (about 40% actually) which is enough to show the effect I was looking for, but not much more.Read more

Photometric observer Richard Miles reported a V band magnitude of 3.02 for epsilon Aurigae this past week, which essentially matches the pre-eclipse average and signals the end of optical eclipse (4th contact).  The long march through eclipse is over.  However, we still need your observations for at least the balance of this year in order to more precisely define 4th contact after-the-fact, and to characterize the magnitude of out of eclipse variations (~0.1 mag in V).   Information on the latter will be helpful in comparison with planned post-eclipse observations with both the CHARA Array MIRC imager (with exciting new 6 telescope mode) and the IRTF SpeX infrared instrument.

What do we learn from the fine light curves now collected?
Step one: timing of events in the light curves.
Step two: analysis of "fine structure" present in the light curves.

Step one: Read more