Observers are reporting signs that epsilon Aurigae's light has plateau'd during the past week or so, suggestive that second contact was reached - that is, the dark disk now stretches across the nearly 1.5 astronomical unit diameter F star. Exact time of second contact can only be determined in hindsight, but the change in the rate of decline is noteworthy. Comparison with last eclipse is informative, although the data density is somewhat less. In part, second contact was not the final, minimum brightness for the system. Rather, another drop of 0.03 mags happened about a month after the initial minimum, then a slow decline over several months until so-called mid-eclipse brightening started around mid-eclipse (and the seasonal close approach of sunlight made those observations very difficult).Read more
This morning, Donald Hoard (Spitzer Science Center) reported on an analysis of a large set of multi-wavelength measurements (ultraviolet, optical and infrared) that provide important insight into the components that comprise the epsilon Aurigae system. Dr.Hoard spoke about this work at the Adler meeting of Citizen Sky August 2009 and you can find the video of his talk on the website.Read more
Citizen Sky has issued a press release (in english and espanol) with an update on the project and including new artwork (including one image created by the aesthetic solutions team). This is being released at the Jan. 3-7 American Astronomical Society (AAS) meeting, billed as the largest meeting of astronomers ever. Citizen Sky will be well represented there through posters, talks and press conferences. We will also be wandering the halls looking for neat news updates to bring you regarding epsilon Aurigae and other astrophysical phenomenon. Stay tuned during the week for reports!
And don't forget to continue your observations!Read more
Did you observe the palindromic date this weekend, 01- 02- 20 10 ?
If you have been observing the steady decline of the light of epsilon Aurigae this autumn, you might wonder if it too will be palindromic - that is, the brightness symmetricaly rising during egress early in 2011, as steadily as it declined during ingress autumn 2009. Short answer, probably not. Among the many wonderful conundrums surrounding epsilon Aurigae is that the eclipse is asymmetrical - egress tending to be fast than ingress.
This difference is thought to be due to asymmetries in the disk - somewhat less well defined on the trailing edge that we'll see later in 2010 and during early 2011 as eclipse ends, relative to the leading edge this past few months.Read more
The end of the calendar year marks an end and a beginning for many cycles, among them the annual bird count conducted by the Audubon Society - this year being their 110th census, making it the longest-running volunteer or citizen science effort. Results of the Christmas Bird Count are being used to gauge climate change effects, among many other purposes. Many birders are also avid astronomers, sharing a love of observing and recording data. AAVSO - the American Association of Variable Star Observers - comes in a close second at 98 years, for conducting one of the longest running citizen science activities as well. The millions of observations reported to AAVSO are useful for all kinds of astrophysical studies, including this focus on epsilon Aurigae.Read more
For the Northern Hemisphere of Earth, we have arrived at the winter solstice and the light has faded. For us in the north, spring is only 3 months away. For all of Earth, however, we will remain in the shadow of the disk in the epsilon Aurigae system for the next 12 months and then some - until nearly spring of 2011. Thus, we will be deprived of some of the warming photons coming to us from the F star in the system, while the dark disk intrudes and lingers in the line of sight.Read more
As part of the registration process, we asked new participants what they felt would be their biggest challenge in this project. The #1 answer, by far, has been time. So we've put together a table of the amount of time needed for a sampling of roles in the project...Read more
It's December 8th evening, Julian Date (J.D.) 2,455,175 and we are only a few days from predicted time of Second Contact when total eclipse starts.
The words "1st, 2nd, 3rd, 4th contact" refer to moments when objects in eclipsing systems overlap partially and totally. Consider a small circle crossing in front of a bigger circle: first, just the outsides touch (1st contact); then the small circle just gets fully inside the larger (2nd contact); later, the smaller circle begins to exit from inside the larger circle (3rd contact), and at the end, the circles stop touching at their edges, before separating (4th contact).Read more
Note: Next eclipse is Dec. 23. Algol, a.k.a. "The Demon Star" has some very well-timed eclipses for the month of December. It's a very bright naked-eye object and an entire eclipse can be seen in 4-5 hours. It's great training for epsilon Aurigae!Read more