Tue, 02/20/2024 - 17:42
Hi all. I came across this object during the SuperWASP program in Zoouniverse. VSX type is EC, but plotting SW data in VeSPA portal shows a shape that shows a shape that seems suggestive to me for EB, with very different minima. Or is it a form bordering the two categories?
VeSPA phase plot here: https://www.superwasp.org/vespa/source/1SWASPJ051700.49-555510.8/#period-68289.84375
Thank you for any comments you may wish to make.
Franco
Hi Franco,
Yes, it is indeed an EB.
I have revised it in VSX:
https://www.aavso.org/vsx/index.php?view=detail.top&oid=77283
Cheers,
Sebastian
Thank you very much, Sebastian. I'll take this opportunity to ask a question (perhaps useful for other inexperienced people like me) : is there any checklist, or rule, that allows you to distinguish EB and EW in doubtful cases ? Spectral class ?
Cheers
Franco
Franco,
the classification system is rather complex. It is based on different parameters that are sometimes contradicting with each other.
Light curve shape: EWs have similar minima, EBs have different minima depth.
Mass: EWs are low mass systems, usually with spectral types F-K, while EBs have spectral types O to F.
Period: Related with the above, the periods of EW systems are shorter than those of EBs. EWs have periods shorter than 1 d., most of them 0.2-0.5 d. while EBs tend to have periods longer than 0.5 d. This is not a fixed rule but all parameteres are related to each other.
Cheers,
Sebastian
Thanks. So may exist some overlapping and uncertainty, and therefore, in some cases, the EW/EB classification may be justified.
EB/EW can't exist becase "/" implies you are giving a subtype. An EW can't be a subtype of an EB.
You surely meant EB|EW.
"|" means "or".
Anyway, in all cases you can surely give one type and if there is uncertainty, you can add a ":".
I don't recommend using EB|EW even when it is accepted. It is mostly used when importing survey lists that do not provide an eclipsing subtype.
Cheers,
Sebastian