Date: Mon, 12 Apr 93 15:11:18 PDT From: hgcjr@ipac.caltech.edu Subject: Photoelectric sequences for M81 field stars Daniel Green at the IAU Central Telegram Bureau in Cambridge tells me that there has been some confusion about the identity of the stars in the UBVRI sequence that was published in IAUC 5742. In short, I can find no problem with the identifications of the stars in either my own records, or in the Circular. Here is the longer story: I have checked my original finding chart of the field and find that I adopted the sequence nomenclature of Brandt, Kalinowski, and Rosen (ApJS 24, 421, 1972) on that chart; the nomenclature in my nova net message of 5 April is based on the right ascensions from the GSC. The data were transferred correctly to the Thompson-Bryan chart of N3031 from my photoelectric reduction output, and the GSC identifications -- based on the GSC positions in my table sent to Drs. Green and Marsden -- in IAUC 5742 are also correct. The following table collects all the photoelectric data which I know about now for stars in the Thompson-Bryan field. The sources (given in the "Other" column followed by the star identification within the source) are: JN -- J. Neff, in Brandt, Kalinowski, and Rosen. 1972, ApJS 24, 421. BH -- Brandt and Hiltner, ibid. AS -- Sandage. 1984, AJ 89, 621. HC -- Corwin. 1993, IAUC 5742. TK -- Kato. 1993, April 6-11, nova net messages. OI -- Okyudo and Ishida (in Kato. 1993, April 6-11, nova net messages). Unfortunately, I do not know the sources of the other sequence data which G. de Vaucouleurs has requested (the AAVSO sequence, and the sequence from "The Astronomer"). There may also be other photoelectric sequences in the literature which I've not yet seen. Nor do I find any optical photometry for star "C" aside from the GSC value of 14.59. Using de Vaucouleurs's zero point correction, this becomes V = 14.96. S. Odewahn, C.E. Woodward, and J. Bailey give JHK data for stars "A", "B", and "C" in a nova net message of 9 April. Within the errors, star "C" has the same colors as stars "A" and "B". This suggests V = 14.4 for star "C", in poor agreement with the corrected estimate from GSC. M. Kidger, however, has reported that star "C" has been listed as a possible variable. While the estimates I've just made point to the same conclusion, we obviously need more photometry for this star. With two exceptions, all the stars are in the GSC whose positions I quote. For the two exceptions (Sandage's stars 2 and 21), I have estimated the positions with respect to nearby GSC stars. The label on the Thompson-Bryan chart for GSC 4383-1031 is incorrectly given as "11.6." This should either be changed to "11.7" (to report the V magnitude given by Brandt, et al), or to "11.6 overline" to reflect the V which I measured. Finally, note that the U-B, V-R, and V-I values from my observations are on the Cousins system, while other U-B values are (probably) on the Johnson system. Dr. Kato also reports his I-band photometry for star "A" to be on the Cousins system. GSC Other TB Chart ID RA (B1950.0) Dec V B-V U-B V-R V-I 4383- (from GSC) 0434 HC-1 12.4 overline 09 50 25.6 +69 15 38 12.45 0.63 0.11 0.39 0.76 0308 HC-2 11.8 overline 09 50 35.9 +69 20 04 11.78 0.69 0.16 0.40 0.80 1037 JN-A 14.1 09 51 10.9 +69 04 58 14.08 0.96 0.36 -- -- 1037 BH-A 14.1 14.05 0.98 -- -- -- 0340 "C" 14.0 dbluline 09 51 17.9 +69 15 02 Variable?? 1031 HC-3 11.6 09 51 21.2 +69 05 34 11.62 0.53 -0.04 0.33 0.69 1031 JN-B 11.6 11.73 0.46 0.05 -- -- 1031 BH-B 11.6 11.73 0.51 -- -- -- 0928 HC-4 11.9 overline 09 51 36.1 +69 14 44 11.90 0.50 -0.08 0.30 0.60 0928 "B" 0565 TK-A (Not labelled) 09 51 39.7 +69 16 00 11.41 0.56 -- -- 0.63 0565 OI-A 11.41 -- -- -- -- 1123 HC-5 13.6 overline 09 52 11.1 +69 09 41 13.65 0.57 -0.09: 0.34 0.69 0633 SA-13 13.8 underline 09 52 29.0 +69 22 07 13.78 0.58 0.16: -- -- 0094 SA-9 13.9 underline 09 52 39.4 +69 23 17 13.92 0.80 0.42 -- -- 0224 HC-6 11.8 underline 09 52 39.7 +69 24 18 11.85 1.30 1.29 0.68 1.29 0224 SA-8 11.8 underline 11.84 1.32 1.33 -- -- 0935 SA-14 12.9 underline 09 52 42.0 +69 21 43 12.89 0.73 0.17 -- -- 0598 SA-A6 15.0 underline 09 52 50.4 +69 19 29 14.99 0.69 0.14 -- -- 1158 JN-C 14.9 09 52 53.8 +69 23 49 14.88 0.67 0.06 -- -- 1158 BH-C 14.9 14.88 0.67 -- -- -- 0322 SA-A5 15.3 underline 09 52 58.8 +69 21 17 15.28 1.01 0.69 -- -- 0790 JN-D 14.6 09 52 59.8 +69 24 15 14.58 0.68 -0.02 -- -- 0790 BH-D 14.6 14.56 0.67 -- -- -- SA-2 15.2 underline 09 53 05 +69 15.8 15.15 1.09 -- -- -- 1023 HC-7 14.7 overline 09 53 17.7 +69 24 54 14.73 0.46 0.12: 0.36 0.60: 1023 SA-11 14.7 overline 14.77 0.44 -- -- -- 1028 SA-1 13.7 underline 09 53 27.7 +69 15 46 13.71 0.77 -- -- -- 0244 SA-15 13.0 underline 09 53 33.9 +69 25 03 12.99 1.20 -- -- -- 0860 SA-19 10.3 underline 09 53 58.0 +69 11 44 10.32 0.39 -0.06 -- -- 1005 SA-6 14.0 underline 09 54 08.2 +69 23 16 14.03 0.95 -- -- -- 0262 SA-5 15.3 underline 09 54 11.6 +69 17 54 15.31 0.65 -- -- -- 0582 SA-20 15.0 underline 09 54 17.4 +69 16 18 15.05 0.74 -- -- -- SA-21 15.5 underline 09 54 20 +69 14.9 15.50 0.86 -- -- -- Harold Corwin, hgcjr@ipac.caltech.edu IPAC, M/S 100-22, Caltech, Pasadena, CA 91125, USA
Return to the Powerful Daisaku
vsnet-adm@kusastro.kyoto-u.ac.jp