light curve

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

This semester the Tufts University introduction to astronomy class observed epsilon Aurigae as their course lab. The class has around 250 students and they do not have access to equipment for a formal lab. So epsilon Aurigae was perfect since it is bright enough to be seen from campus with the unaided eye and happens to be emerging from the eclipse. They were tasked to observe once every two weeks and report their data to Citizen Sky.

(about light curves)

The above light curve includes all Citizen Sky data since February 1, 2011. The blue line is the 7 day mean curve based on data only from Tufts students. The red line is the 7d mean for visual observation from non-Tufts Citizen Sky participants and the green line is for photometric observations from Citizen Sky participants.Read more

Although we won't be able to confirm until later, that mid-eclipse occurred as predicted during the end of July - beginning of August, all the evidence strongly suggests it's so. 

• Despite solar conjunction at the start of summer, photometric monitoring continued, but little evidence for Mid-Eclipse Brightening has been produced thus far.  In fact, a first minimum during totality was reached near RJD 55250 (V ~ 3.8), then slowly rising toward mid-eclipse values close to V ~ 3.6Read more

Despite a spring blizzard, we made it to our 28 inch f/21 RC telescope at Mt.Evans Observatory in Colorado (14,148 ft elev) and visually inspected epsilon, zeta and eta at low airmass mid-day Tues 6/15/2010.  Brian K and I agreed that eps and zeta were of comparable brightness, after several iterations.  I think eps is slightly fainter than zeta when color differences are taken into account, but that gets subjective under bright sky conditions.  Thus, we report no indication that epsilon Aur is brighter than zeta Aur at this time.  Hence, no evidence for mid-eclipse brightening at this time, but further reports to follow.

With mid-eclipse forecast for early August 2010 and mid-eclipse brightening supposedly lasting +/- 30 to 45 days around that point, we should either begin to see evidence for it soon, or redefine the mid-eclipse light curve.Read more

This weekend marks both the 66th anniversary of D-Day, and the annual closest approach of the Sun to epsilon Aurigae - a scant 28 degree separation.  If you've been attempting observations from anywhere in the northern hemisphere, you've seen how low the star is after sunset and how bright the lingering twilight has remained.

A fine screenshot shared by Thierry Garrel is appended, showing the cumulative effect over the past days, of the increasing twilight (scattering solar spectrum photons) on attempts to acquire spectrum of epsilon Aurigae (in this case, near the H-alpha line).  Despite this, he and Robin Leadbeater appears to be able to extract consistent data (see image two).  My thanks to these stalwart observers for sharing their findings.Read more

A  new, open-source data visualization and analysis tool called VStar is now ready for download.  It is the product of a Citizen Sky programming team led by David Benn - VStar Software Development Team.  We are very proud of VStar and thank the team for the many, many hours of hard work that have gone into creating this tool.

A brief description, some simple instructions, and a download link are available on the VStar page. Read more

Half-way through ingress by most estimates, but epsilon Aurigae continues to confound.  Middle of October, the star changed its rate of decline in brightness, from rapid to less rapid - see the visual light curve data link.  This change of slope seems to be more pronounced at shorter wavelengths, less pronounced at longer wavelengths.  Clues like these will help us define the nature of the eclipsing body more precisely.  If purely due to effective area, it says that the disk is slightly thinner-looking in bluer light, relative to red wavelengths.  Ultraviolet light curves during last eclipse seem consistent with this trend.Read more

   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

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

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