Blog / Monthly archive / October 2009
October 2009
Hot on the trail...
Greetings from Mount Wilson, home of the 100 inch telescope used by Hubble, and home of the CHARA interferometric array. Brian K and I have been assigned CHARA time with the team to pursue high resolution imaging of epsilon Aur as it undergoes eclipse. With the light 50% diminished (see previous blog), the Huang model predicts that the dark disk should be significantly intruding across the face of the F star.Read more
Two New Ways to View Data!
You can now view up to the minute data on the Citizen Sky Website for any of the 10 stars from the 10 Star Tutorial! You have the choice of plotting a light curve or displaying the individual data points in a list. Our web developer Kate has added some neat extra features like the ability to highlight your own observations and the ability to plot means on the light curve. You can find these new features in the "Data" tab under "View."
We have some interesting things coming down the pipeline in the next couple of weeks, so stay tuned for announcements!Read more
Halfway there!
Observers are reporting visual magnitude approaching 3.4, which is half-way between the out of eclipse average, close to 3.0, and the anticipated magnitude during totality, 3.8. Hopkins and Santangelo have begun to converge on JD 2,455,065 (+/- a few days) as the likely time of first contact (start of eclipse). Today being JD 2,455,127 (23 Oct), that was 62 days ago. At this rate, we'll bottom out in totality by JD 2,455,189 or slightly sooner - close to winter solstice. Jeff Hopkins predicts 2,455,183 for visual, and earlier in photometrically bluer wavelengths.Read more
Online Chat Transcript w/Brian Kloppenborg
(Post Chat Update: The transcript has been posted...) Original announcement was:
Join us Sunday, October 25 at 7pm EDT (23UT) for an online chat with Brian Kloppenborg. Brian is Dr. Bob's graduate student at the University of Denver and a key advisor/scientist/everything-person for Citizen Sky. We'll talk about all aspects of CS so bring any questions you have. Just visit this web page to join us.
As always, the transcript will be posted online for those who cannot attend. Transcripts of other chats can be found here.Read more
Videos from the First Citizen Sky Workshop are Now Online
In August 2009 Citizen Sky held a workshop in Chicago on epsilon Aurigae and observing. Most of the talks during this workshop were videotaped. The first set of videos are now online along with their corresponding presentation files. If you missed the workshop or if you would like to revisit your favorite talk, check it out. More videos are on the way, so stay tuned!
A Delay in First Contact?
As noted by Jeff Hopkins in the Epsilon Aurigae Campaign newsletter and a recent Astronomer's Telegram, the eps Aur eclipse seems to have started later than was predicted by data from previous eclipses. What could be the cause of such a change? How could you confirm your theory?
The scientific process often begins with a thorough discussion of the problem and brainstorming solutions with colleagues. In an effort to start such dialog on Citizen Sky, I've started a forum to discuss the apparent shortening of the eclipse. I'm sure with several people discussing the topic, we will be able to solve this mystery.Read more
As the light curve wiggles.
As the light of the primary star continues to wane, discussions of the time of "first contact" have arisen - that's when the dark disk began to encroach on the F star photosphere. Pre-eclipse predictions indicated the date could be JD 2,455,055 = 2009 Aug.11 (Hopkins & Stencel, 2008 Epsilon Aurigae - book - p.97). Different observers point to slightly different times to represent the start of ingress.
Jeff Hopkins (Hopkins Phoenix Observatory) has analyzed light curve data and concluded the eclipse began (V band) on JD 2,455,072 = Aug 28.
See his webpage at http://www.hposoft.com/Plots09/FirstContact.JPG .
Italian observer, M.M.M.Santangelo (Osservatorio Astronomico di Capannori) has published statistical results of his independent photometry in issue 2224 of the Astronomer's Telegram and states that the eclipse "did not still take place until at least August 17th" = JD 2,455,060. Read more
Citizen Sky now on Facebook
Citizen Sky now has a fan page on Facebook. Check it out: www.facebook.com/CitizenSky
Supergiant Binary Stars - Video from Workshop
The first video from the Chicago Workshop has been posted to the forums. It's a talk about supergiant stars by Dr. Doug Welch. Consider this a sample of much more video coming soon.
Fading faster...
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
