[vsnet-newvar 1768] Re: [vsnet-campaign 1356] VSNET Weekly Campaign Summary

[DWest61506@aol.com]

In a message dated 12/30/2002 11:41:04 AM Central Standard Time, uemura@kusastro.kyoto-u.ac.jp writes:

BU Tau        (RA = 03h49m11s.19, Dec = +24d08'12".4)

    P. Harmanec commented that for at least three years BU Tau is in
  its undisturbed state with V=5.04 mag.  The current brightness
  corresponds roughly to the true brightness of the central star,
  unaffected by a contribution from an envelope (vsnet-campaign-be
  205).  On the other hand, D. West reported his observation of
  V=4.91+/-0.02 on December 22, which indicates that it is getting
  brighter (vsnet-campaign-be 206).

P. Harmanec contacted me by e-mail and ask if I could measure BU Tau using 18 Tau (V=5.684) as a comparison star.  Last night using my SSP-3 with a V filter (1/4/2002 1:00 UT) I measured BU Tau at V=5.05.  My check star was SAO 76228 which measured at V=3.64.  SIMBAD gives V=3.62 for SAO 76228.  From this observation I conclude that BU Tau has not brightened as I previously reported.

This result brings up the question as to why my previous CCDV observations of BU Tau were ~0.14 magnitude too bright.  I went back and measured HD 23873 relative to SAO 76228 (V=3.62) and got V=6.76.  HD 23873 was the comparison star in my previous CCDV observations.  Apparently HD 23873 has faded by ~0.16 magnitude.  SIMBAD lists HD 23873 at V=6.606 with spectral class B9.5V.  The UBV catalog shows a range of 6.57 to 6.62 for this star.  More observations will be required to confirm the fading of HD 23873.

Regards,
Doug West
http://hometown.aol.com/dwest61506/index.html

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