Hi All,
(Please forgive my bad english, and don't hesitate to correct it, if necessary)
I'm Christophe, french amateur astronomer, amateur of photometry and variable stars.
I would like to present you a call for observations relative to 41 bright stars that are suspected to be long period binary stars. No eclipse were ever observed/recorded for those stars.
This call was originally published in french/France a few days ago for the french amateur community, and it would nice if some observers here or there, in Europe, from the opposite part of the pond, or in Asia, would also be interested in it.
The periods of the candidates were derived from the GAIA DR3 catalog, and are always in hundreds of days, ranging from 200 days to 400 and more days.
The exact duration of the eclipses and deep are unknown, and have to be caracterized, but some eclipses could last for several dozen of hours.
Photometry and spectropscopy :
Time series are generally requested for several weeks around a precise date. Ephemeris will be uploaded here, or could be found on the GeminiPRO-AM website (url provided below, in french).
TriG, TriB, TriR, G, V, R, B and other classic photometric filters can be used.
Spectrocopy is welcome, especially near the eclipses, if they are ever found.
The main goal is to find or reject any possibility of eclipse.
Each star candidate will be observed spectroscopically with the very high resolution SOPHIE spectrograph at the T193cm of the Observatoire de Haute Provence (OHP) before any publication of ephemeris.
You can read the original paper below, by J.-L. Halbwachs et al, Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, F-67000 Strasbourg, France.
The first star candidates with an accurate published ephemeris are :
- HD29410, to be observed in december 2023, right now, indeed.
- HIP 8342, to be observed in january and feb 2024
(Ephemeris below)
Observations will have to be send directly to JL Halbwachs (email adress on the ephemeris paper).
We could/should discuss about any observations here, post LC and other aspects of this adventure, if needed ; and alerts, if any, will also be provided here, as well as any follow up.
I will try to find those eclipses by myself, altogether with other observers in France (Gemini project), if any, with several optics ranging from 50 to 280 mm in diameter, depending of the circonstances, and a 650D canon DSLR.
I hope there will be some interested observers to help finding those new eclipsing binaries.
Thank you for reading,
Good skies,
Christophe
The Gemini Pro-AM website (in french) :
https://proam-gemini...ires-a-eclipse/
There is a video conference about the full story (in french).
The original paper :
Edited by chrismlt, 12 December 2023 - 12:01 PM.