Eclipsing Binaries (EBs)

Hello! I've been trying to get several nightly observations each week of EA V0645 AUR.

    Last night's photometry showed a drop consistent with the eclipse, but it was 2.2 days early according to the ephemeris in VSX.

    During the last 6 months, I've only caught two magnitude drops consistent with eclipses as well as some irregular increases in magnitudes (most pronounced in I).

    1) What might have caused the drop in magnitude 2.2 days early that I saw last night, 04-04-2020?

AAVSO Alert Notice 700 announces an observing campaign underway on the long period eclipsing binary EE Cep. Please see the notice for details and observing instructions.

Many thanks, and Good observing,

Elizabeth O. Waagen, AAVSO HQ

Hi all!

On January 25th, I saw the UMA delta weaken to 3.77 . Perhaps an eclipse has begun? Please confirm or deny my observation.

All the best, Ivan

Gamma Persei is a long term eclipsing binary. The first ever eclipse minimum of Gamma Per was observed in September 1990, about which, some scientific publications have been written. The following eclipse was expected to be in April 2005, but no definite expected window was described anywhere. From late March to end of April 2005, I did observe the star and took a few digital images of the sky around it as well. In only one of these observations, I noted Gamma Per to be slightly fainter than normal; mag. +3.1 instead of +2.9, which was on 18th April 2005.

Bob Nelson’s Excel Workbook sheets are valuable to those of us who calculate ToMs. However, they lack documentation in two important cells.

1. In C5, does the cell take into account DST? For example, in my time zone (Central) do I input “6” or “5” when daylight savings is in effect?

2. In Column F19: May I assume this is UT date and time?  No local time, correct?

Ed

I see Binary Maker referenced in many JAAVSO articles and AAVSO forum posts so I know it is widely used.  I am curious if folks who use it feel it is worth the price.

Thanks in advance for any comments,

Cliff

I am attempting to phase an object that I believe is an eclipsing system. While I can successfully phase the ROTSE1 and SuperWasp data to align the primary minima, none of the surveys I have used thus far (CRTS, APASS, ASAS-SN, NSVS) have data points that corroborate the second minima. I am fairly confident that the period is 1.222492 days. Are there any additional surveys that would be sensitive enough to substantiate my plot?

Hello,

I'm currently writing a paper about recently found highly eccentric bright EA+DSCT variable TYC 2722-1304-1. I would like to additionally calculate eccentricity and ω of this system using shape, position and duration of asymmetric eclipses. I don't have access to make radial velocity measurements, unfortunately. Can anyone link a software to designate such parameters? I have found only one written in Python, but I don't have any knowledge about this language. Is there something easier to do?

I've observed a few EB's, mostly to have some "fast moover" data for students to analyze, since they get much more excited when the curve is showing more "action".

Now I have a student who wants to learn photometry, but also spectroscopy.  I'm hoping to ID a few really interesting targets that can be used for both.  Not out of laziness, but to get the most bang for the buck in terms of imaging time, the hours of clear sky available during the winter, and her college schedule.

Any idea when the 2018 EB Ephemeris will appear?

Ed