Thu, 02/04/2021 - 17:41

Hi, i observed this star at V at 9.216 and B at 8.908 on Feb 3, 2021 evening. This seems wrong? anyone?

Observer Code: HHAD

Affiliation
American Association of Variable Star Observers (AAVSO)
Unrealistic B-V

Hello,
yes, that is not okay so there seems to be a problem with the B observation. B-V= -0.31 is even bluer than the bluest stars.
According to Tycho, this HADS has a mean B-V of +0.27. As any pulsating variable, there will be some color changes involved because the amplitude is larger in B, but that means something like +0.2 at maximum and +0.4 at minimum, so -0.31 is out of the question.
If your V observation is fine, then you caught it near maximum so B should be around 9.4-9.45.
I can't help further, I'm not a photometry expert, but at least I was able to give you some insight from the star's nature side.

Cheers,
Sebastian