[vsnet-chat 5498] UV stars (FZ And, HW And)

[Seiichi Yoshida <comet@aerith.net>]

Dear colleagues,

What is a "UV-type" star?

The type of FZ And and HW And are recorded as "UV":

  http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/gcvs/ANDFZ.html
  http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/gcvs/ANDHW.html

  FZ And : 15.2-16.25 mag(B)
  HW And : 12.7-14.4  mag(P)

We the MISAO Project observed these stars. The observations were
reported to vsnet-obs on Sept. 1.

Then, I found three questions on these stars.

(1)	FZ And is recorded in the USNO-A2.0 as 13.8 mag(R), 16.4
	mag(B). 

	I imagine the "UV-type" star is bright in ultra-violet. 
	However, the USNO-A2.0 color suggests that FZ And is a red
	variable.

(2)	The USNO-A2.0 color suggests that FZ And is a red variable.

	However, FZ And could not be detected from any MISAO
	unfiltered red-sensitive CCD images on 7 nights, as fainter
	than 15.4-16.3 mag. It is strange for a red variable around 16
	mag in B-band.

(3)	I imagine the "UV-type" star is bright in ultra-violet. 

	However, HW And with a range of 12.7-14.4 mag (photographic)
	could be detected from MISAO unfiltered red-sensitive CCD
	images as bright as around 12.3 mag.

The UV-type stars FZ And and HW And were in the MISAO unfiltered
red-sensitive CCD images. FZ And was too faint to be detected, but on
the other hand HW And was bright.

So these two stars do not seem to be the same type to me.

No observations of them have been reported to VSNET.

Best regards,

--
Seiichi Yoshida
comet@aerith.net
http://vsnet.aerith.net/

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