Tue, 12/04/2012 - 12:54
Dear Forum members,
I am doing a Master's thesis project at Lund Observatory, Sweden, on RR Lyrae variables. For this I need up to date epochs for SV Eri and DX Del. I tried using the VSX of AAVSO, but there I found rather old epochs:
SV Eri: 19 Mar 1956 (HJD 2435552.109)
DX Del: 29 Aug 1966 (HJD 2439367.34000)
The GCVS on the web also has some old epochs. Can more recent epochs be found elsewhere, or are epochs from ca 50 years ago still useful for calculating times of maxima?
Kind regards
Anders Nyholm
Lund, Sweden
Anders,
Go to http://simbad.u-strasbg.fr/simbad/ and click on queries by identifier. Type in V* SV Eri or V* DX Del and click the submit ID button. Scroll down a little way on the resulting page and you will see a References section. Click on the Display button on the right side of the screen. You will then see a list of clickable papers for that object, many of which contain more recent epochs.
You can also do an object seach in the Nasa Astrophysics Data System (ADS) which will get you many of the same papers.
Good luck in your search.
...Tim (HTY)
Anders:
If you search for SAH (G. Samolyk) on the AAVSO web site and click on his contact tab, you can email him and get a recent TOM of SV Eri from him. He is an officer of the MAS and you can also contact him that way.
DX Del is not on the MAS RR Lyr List but he may have info for that star also?
Ken
Here is the URL for NASA ADS:
http://adsabs.harvard.edu/abstract_service.html
Kevin Paxson - PKV
The main on-line source of information for RR Lyr maxima is:
http://dbrr.ast.obs-mip.fr/
Both of your stars are listed there. The AAVSO program, run by Gerry Samolyk, is more limited but also valuable for the stars it contains.
VSX is a basic resource for the variable-star parameters like period and epoch, but it is primarily "populated" from imports of published information. It cannot be kept up to date with the latest results that might exist in dynamic databases like GEOS. It is always advisable to do a little data-mining when such parameters are important for your program.
Arne
Thank you very much for the good answers. I have been able to find useful epochs.
/Anders