I’ve hoping to find a 2025 version of the 12 month schedule for primary and secondary minima siimilar to the one I had found for 2024. However, with the new and improved website, I am pretty much lost relative to the information and target listings that were previously easily findable in the EB Section.
Can someone direct me to this 2025 - 12 month listing or some other resource the lists targets that are particularly relevent and warrant our attention?
Thank you,
Gary
Gary
An expanded version of the ephemeris can be found at:
https://milwaukeeastro.org/variable/binearyEphemeria.asp
This contains all of the stars in the AAVSO legacy program along with some additional stars that I have been following over the years.
G Samolyk
Gary, thanks for that link. The expanded version has quite a few more stars than the “standard” ones posted on AAVSO. It will be quite useful for picking targets.
Thank you very much for the listing. This is exactly what I had been looking for as a 2025 update. It’s also nice to know the original source.
Is there a source within AAVSO/EB Section, that might highlight targets that are of more immediate interest or most urgently in need of new and ongoing observations?
Thanks again
Gary Shaw
Gary
The goal of the legacy observing program is to document changes in the orbital periods of these stars over the long haul. I have been observing some of these stars for over 50 years. It is amazing how many times a period can change in a single human lifetime.
As for prioritizing observing targets, a glance at the ephemeris shows that some short period stars can be observed every night while other stars can only be observed a few nights per month. The fewer the opportunities, the more important the observations. Particularly for stars with a long total eclipse where a long observing run is required to obtain a time of minimum. Another criteria, is to put a priority on southern stars. I use the short period stars to fill gaps in my observing schedule.
Do you plan to publish times of minima that you observe? If you would like me to include them in the JAAVSO papers that are published in each issue, please send me a copy of your data (in addition to uploading it to the AID). You can contact me directly at gsamolyk@wi.rr.com.
One other point, make sure that the computer clock is accurate to one second or better. Also make sure that the time of each observation is the midpoint of the exposure rather than the start time. The accuracy of the time of minimum can be close to 0.0001 day so seconds matter.
Gerry Samolyk
Thanks Gerry,
I do plan to report via AAVSO and copy you as I have done a few times in the past. I’d planned to ask you first if that process still made sense but your note has answered that.
Regarding prioritizing targets, I had hoped someone had already developed a list of targets that are most in need of data or that are of added importance for one reason or another. I’ll gladly make time to plan and obtain observations on targets that might be available infrequently, have long eclipses or that are otherwise difficult to obtain, but I’m less inclined to comb through a long list of targets to determine which targets meet those criteria.
On the prior AAVSO website Forum and Section area, I’d found something referred to as the Otero List which seemed to be structured with observing priorities. There was also an observer in Rhode Island with a website and EB ephemera including some data on number of observations to date on some EBs that seemed relevant to choosing targets in need of observations. I could find neither of these in the new website structure when last I looked. I’ll give it another try later today.
Thanks again for responding.
Gary
ps: I update my computer clock using a NIST time adjustment app before each observation.
I don’t worry much about priorities, other than to give priority to EB’s with long orbital periods and to ones that lie south of the celestial equator. My simple-minded method is to pick an object that has an eclipse in the evening hours local time that is convenient to observe. All of my observing uses a Seestar S50. I use an app that syncs the tablet’s clock with an NTP time server. Then I process the data using Pixinsight, followed by Lesve Photometry on a desktop PC. Finally, I calculate the time of minimum using a Python program that I wrote for this purpose. Alternatively, Peranso is an off-the-shelf program available from cbabelgium. It also calculates time of minimum, along with many other valuable functions.
Andy Howell
HOA
The comment from Andy is spot on. There are stars where there are few opportunities to observe and eclipse in an entire observing season. They are always high on my priority list. Many of the contact binaries can be observed on any night. I use these stars as fillers when one of my scopes has a few hours available before or after a major target. I also use these short eclipses on nights when I only have two or three hours before a cloud front comes in.
The bottom line is, do what works best for your time available. The more you enjoy your observing, the more you will observe.
Gerry Samolyk