[Aavso-photometry] RS Oph Multicolor Photometry - revised

[arne]

Darn, forgot to include the reference for HD163153.  See the revision below.

Mike Simonsen wrote:

 > For the bright stars on the current AAVSO charts we used Bjorn Granslo's
 > sequence for this field.
 > (GCPD, Tycho and Henden magnitudes)
 > http://www.astro.uio.no/~bgranslo/sequence/
 >
 > You can get UBVRI from the Mermilliod catalog (GCPD) here:
 > http://obswww.unige.ch/gcpd/indexform.html
 >
There are actually 4 decent 6th magnitude comparison stars in
the field, all visible on the B-scale chart:

   Star      RA (J2000) DEC        V       B-V      U-B     V-Rc     Rc-Ic note
HD162834 17:53:15.38 -05:55:44.0 6.859    1.266    1.129    0.966    0.748 (c)
HD162713 17:52:37.06 -05:15:43.4 6.84(2)  1.01(2)                          (b)
HD161056 17:43:47.02 -07:04:46.6 6.31(2)  0.37(1) -0.49(2)                 (a)
HD163153 17:54:57.67 -07:44:02.2 6.926(4) 0.759(1) 0.415(3) 0.405(2) 0.354(4)(d)

(a) B1.5V also HR6601, Cousins 1964; starE, "63"
(b) K0 Tycho2; Granslo uses mean of Tycho2 and Kornilov, starF, "68"
(c) K0 double system ADS 10861A, Schmidt 1971, ApJ 165, 335; NE of "Y"
(d) G5; Landolt 1983, AJ 88, 853; upper right on B-scale

HD162834 was used by Schmidt to study Y Oph.  He gives no errors.
Since both Tycho2 and Kornilov are on slightly different systems than
Johnson, I just went with the transformed Tycho2 values for HD162713.  The
difference is about 0.02mag, so probably not important.
Unfortunately, the chart was already made by the time of this outburst,
and we could did not want to modify the chart to add additional 68/69 stars.

Hope this helps!
Arne