Epsilon Aurigae

My first two posts about the Seattle AAS meeting focused on the two Citizen Sky posters and a slew of posters and the special session dedicated to epsilon Aurigae. This post is fulfillment of a promise: a discussion of the interferometry poster, along with one extra bonus: a "wow" image.
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Greetings from day 2 of the AAS meeting in Seattle, WA. 

Today was the big day in terms of eps Aur activity.  There was a dedicated poster session as well as a special session with talks dedicated to the system.

You can view information about the talks here on the AAS website and the poster abstracts here.  We also recorded the talks and will post them to CSky once we increase the audio and get a copy of the presentations so you can follow along.

A few highlights from the talks / posters:Read more

Dr. Bob and I are taking turns explaining the implications of the recent Nature paper.  In the first post, Dr. Bob discussed two very important questions: "How big?" and How massive?"  In this post, I'm going to cover another big-picture topic: the orientation of the disk.

I'll start with what we thought happened.  Most of the literature drew the disk as something that more-or-less bisected the F-star, following Kemp's 1986 drawing (note, a similar drawing was also published in the 1985 epsilon Aurigae conference proceedings):
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We are pleased to announce that images of the disk occulting the F star were obtained interferometrically during ingress (autumn 2009).  Details of this will appear in this week's issue of NATURE journal, April 8th edition.  Watch this space later in the week for more discussion about those pictures and what they tell us.

It's been a long road to get those images that confirm the disk explanation for the epsilon Aurigae eclipses.  Previous blogs and many online sources help explain the method, but its application to epsilon Aurigae has only really become practical this decade with the improvements in "closure phase" imaging made possible with the NSF-sponsored Michigan IR Combiner (MIRC) instrument, at the CHARA array atop Mt. Wilson.Read more

I have just posted a literature review to the forums in which I discuss the heated disk model for the eps Aur system. 

So far this makes five mini-discussions on eps Aur literature.  I've barely scratched the surface so if there is something you are wondering about, let me know and I'll see if I can find an article discussing it!Read more

We have a guest blog article from a coauthor of a recent paper published about epsilon Aurigae. The author describes the system overall for new participants, then describes what they discovered with their radial velocity data. Read more

Like the autumn leaves, light from epsilon Aurigae is dropping fast.  I've been using a simple digital camera and recorded a fade to V ~ 3.35 this weekend (10/3/09).  If you have been watching the show week to week, epsilon is clearly fainter than eta now, and on its way to being no brighter than zeta in a matter of week, if all keeps to schedule.

As Aurigae is rising by 10pm local time, you no longer need to catch it during pre-dawn hours to see the eclipse happening before your eyes.  Catch those clear, cool nights of autumn and enjoy the spectacle!Read more

Eclipse is underway (V = 3.23 on 9/25/09)and the debate over when First Contact really occurred has begun.  Initially, Jeff Hopkins figures it to be RJD 55072 (late Aug) while Richard Miles likes a date several days prior to that (mid-August).  Whether the final answer is JD 2,455,072 or a week earlier, in either event it appears to be at least one week after predicted start (55055, early August).  This arguably means further changes in eclipse shape and duration can be expected.  Read more

It appears that through the end of July 2009 epsilon Aurigae is still very bright.

The following is from data submitted to the Campaign for July 2009.

Richard Miles

Golden Hill Observatory

Location:  Stourton Caundle, Dorset, England

Latitude/Longitude/Altitude (ASL):  West 2.405 deg, North 50.931 degRead more

The Sky & Telescope web site has an article on Robin Leadbeater's spectroscopic observation of first contact. Note: you can now download Dr. Stencel's S&T article at no cost.

Good work Robin!

Jeff Read more