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
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
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
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
How the time flies. Seems like yesterday (actually 2005) when the first observing proposals* for monitoring epsilon Aurigae were being submitted - and suddenly we have arrived at predicted mid-eclipse. According to Jeff Hopkins, who has made a study of the light curves, he expected mid-eclipse to occur August 4th, 2010 = JD 2,455,413.
The light curve shows no strong evidence for "mid-eclipse brightening" thus far. Now that epsilon Aurigae is getting well separated from the sun, airmass corrections are less a problem, so more accurate photometry is possible. From Mt.Evans this week, we had an exceptional morning for J& H band work, very good signal to noise, but found the brightness was close to that reported during spring 2010 - well into totality.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