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Subject: AD Men identification Originally Tom Richards had questioned about the identification of AD Men on Apr. 6. >The Downes catalog image of the same field shows a brighter star 13" from >the one it identifies as AD Men, at p.a. 123d. It is not visible on my >image. I wonder if that is AD Men, and Downes has mis-identified it? Today, Berto Monard noticed it independently. >There is a star 0.2' ESE of AD Men, which seems to vary. In the cv >atlas it is shown bright, but on my 27 March image it is faint and on >the 2 May image it is bright again. This variable is not in UCAC1. >On those dates AD Men itself (at the cv atlas position) was 16.7 and >16.9CR respectively on my images. I have examined the DSS images and found that the ESE star was caught in outburst in the plate taken on 1987 Nov. 28 (R-band) but dim on the plates of other epochs. The object marked on VSNET page/Downes' chart (at the nominal position of AD Men: 06:04:28.60, -71:25:15.6) differs from this outburst object. Outbursting object on 1987 Nov.; GSC2.2 06:04:30.836 -71:25:22.25 F=14.80(!) J=18.71 USNO-A2.0 06:04:30.845 -71:25:22.28 r=17.0 b=18.3 = 2RXP J060431.1-712523 (no 2MASS counterpart) The marked object: GSC2.2 06:04:28.526 -71:25:15.26 F=16.62 J=17.66 USNO-A2.0 06:04:28.514 -71:25:15.38 r=16.3 b=17.3 2MASS 06:04:28.69 -71:25:15.4 J=15.333 H=14.923 K=15.036 The error circle of X-ray source [HP99] 1272 ( 06:04:30.6 -71:25:29 unc=22" ) contains these two stars, but the former is nearer. Zwitter and Murani 1995, A&AS, 114, 575 reported a spectrum of "AD Men" at 06:04:28.78, -71:25:56.4 (J2000.0). It was B ~ 14.5, so they thought it to be at outburst. The spectrum shows a blue continuum with hydrogen Balmer absorption lines. But this position is almost identical to the GSC 9172.887 (also cataloged in UCAC1, 2MASS, USNO-A2.0/B1.0, and GSC 2.2). They seem to have observed yet another star about 40" south of the nominal position of AD Men. Though I cannot access the discovery literature (Hodge and Wright, 1967, "The Large Magellanic Cloud"), I am quite certain that the first star (06:04:30.836 -71:25:22.25) is true "AD Men". The marked object in VSNET page or Downes' online chart shows no significant change among the DSS images, though a slight change is noted by Berto. Sincerely Yours, Hitoshi Yamaoka, Kyushu Univ., Japan yamaoka@rc.kyushu-u.ac.jp
Return to the Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
