V4074 Sgr From the old query in vsnet-chat 522-534: > Hi, > > I just wish to query the position of V4074 Sgr as shown on the > new VSNET chart. > I have been monitoring this variable for some time, its position > verified against that shown in the New Years edition 1987 of the > Duerbeck atlas. In this case it concerns the 'object' shown on the > VSNET chart as star 11.50 and not the star indicated as V4074. > > Perhaps the actual V4074 Sgr position has been reviewed since > then (as was its nova classification) , I am in no way to know! > Can someone look into it? > > Regards, > > Berto Monard, > > --- > > I have identified the object using Allen's photographic atlas of > symbiotic variables. This identification is truely different from > Duerbeck's. The source reference listed in Duerbeck's lacks a finding > chart. The position quoted in this reference agrees with Duerbeck's > position. > > Interestingly, these two "candidates" for V4074 Sgr are found to be > listed as peculiar objects. > > Duerbeck's object: > > 181605.50 -305111.5 (2000.0) 11.1 GSC > 181252 -3052.3 SGRV4074 ZAND 8.6 12.3 P > 181605.4 -305110 (2000.0) SS1-149 13.0 11.5 7 Z AS295 > 181605.5 -305111 (2000.0) 1150H Hipparcos > > Allen's object: > > 181612.19 -305208.2 (2000.0) 10.8 N GSC > 181612.3 -305208 (2000.0) PK1-6.2 > 181612.5 -305208 (2000.0) ESO457-PN2 > 181612.2 -305207 (2000.0) 1094H Hipparcos > > 181611.1 -305150 (2000.0) 167362 (emission line star) > > original AS catalog (no finding chart): > > 181250 -3053 (1950.0) AS295 > > Which is the real V4074 Sgr?? > > Regards, > Taichi Kato > > --- > > I have noticed some more intersting identifications. > > Allen's object: > > IRAS18129-3053 181257.5 -305312 (1950.0) > > Just midway between Allen's and Duerbeck's: > > 181607.5 -305156 (2000.0) MWC288 11.8 Pec > > Probably either there exist two emission line stars in this field or > much confusion. > > Regards, > Taichi Kato > > --- > > Actually, "Allen's star" coincides with PK 1-6.2 = SwSt 1 marked in the > findng chart of Perek and Kohoutek's PN catalogue. This catalogue classified > the PN as class I (stellar appearance). According to Allen's description, > his finding chart apparently followed Perek and Kohoutek. However, Allen > gave his own spectrogram of AS 295B, which apparently shows emission lines > (including forbidden lines) superimposed on M-type continuum -- apparent > symbiotic spectrum. If Allen took his labelled star, it is difficult to > reconcile with the simple PN interpretation of this star. Or he mistook > the finding chart only? > > In AS catalog, AS 295 was listed as MHalpha 304-41, 2' n.p. HD 167362. > This description agrees with Duerbeck's identification, but it seems > a little strange there was no mentioning about the emission-line nature of > HD 167362. In Henize's catalog, only the position (18h 09m.6 -30o 54' > 1900.0) was given for Hen1641. Again there is no entry for HD 167362, > though this catalog seems to bear the nature of compilation. > > Wouldn't it be the fact there is only one emission line star, which > was at times classified as a planetary nebula, and at times a variable > (symbiotic) star? > > Anyway, please avoid using the VSNET chart for V4074 Sgr. Hipparcos > stars in this field being almost certainly of peculiar nature, this chart > would require independent calibration. > > Regards, > Taichi Kato > > --- > > Hi everyone, > I thoroughly investigated the position of V4074 Sgr a few years ago, and > these are my conclusions. > > 1. There are indeed two emission line objects in the vicinity. V4074 Sgr > has been known as H-alpha emission line object since 1950. It is 3" due > south of a 12th magnitude, normal K0 III star. > The other object is HD 167362, a planetary nebula. > Positions (1950): > V4074 Sgr : 18h12m51.9s -30d52'16" > HD 167362 : 18 12 55 -30 53 10. > > D.A. Allen and Duerbeck agree with their published coordinates, and are > both, to all intents and purposes, correct. > > Finder Charts: > Duerbeck's chart is correct, but is hard to follow. > Allen's chart is wrong. He points to HD 167362, while V4074 Sgr is in fact > 8.5mm W, 7mm N of the indicated position. His chart is easier on the eye. > > Examining Allen's chart under magnification, the images of V4074 Sgr and > HD 167362 are very similar, which is no doubt the reason his chart is > wrongly marked. > > Regards, > Mati Morel > > Refs: > Duerbeck, H.W.: Space Science Reviews, 45/1+2 (1987) > Allen, D.A. : Proc. ASA 5(3),369-385 (1984) > > --- > > You might be correct. There are often multiple entries for a single > object in SIMBAD, and it seems as though this field needs checking. > \Brian > > --- Now 2MASS presents additional information: First star: GSC7392.1189 181605.49 -305111.6 (2000.0) 11.02 6 GSC7392.1189 181605.51 -305111.5 (2000.0) 11.25 6 USNO0525.27411778 181605.448 -305112.12 (2000.0) 12.0 12.4 * 2MASS 181605.552 -305112.68 (2000.0) 9.091 7.993 7.738 181605.4 -305111 (2000.0) V4074Sgr 11.5 - ZAND 181605.4 -305110 (2000.0) SS1-149 13.0 11.5 7 Z AS295 181606.0 -305100 (2000.0) BE(Buscombe) V=6.7 - - 181605.5 -305111 (2000.0) 1150 TYC7392.1189.1 181605.5 -305111 (2000.0) 1150H HIP089526 plx=4.47(7.92) 181605.5 -305113 (2000.0) - TYC7392.1189.2 181605.2 -305114 (2000.0) SGRV4074 * ZAND 8.6 12.3 P - - - R0/DOW Second star: GSC7392.886 181612.19 -305208.4 (2000.0) 10.91 6 GSC7392.886 181612.20 -305208.1 (2000.0) 10.62 6 USNO0525.27432563 181612.191 -305209.10 (2000.0) 99.9 10.9 USNO0525.27432907 181612.303 -305210.57 (2000.0) 9.7 11.1 * 2MASS 181612.336 -305207.68 (2000.0) 0.000 0.000 0.000 181611.1 -305153 (2000.0) CD-30.15469 10.0 181611.7 -305211 (2000.0) CPD-30.5412 10.2 181611.0 -305208 (2000.0) IRAS18129-3053 17.450 86.000 23.850 5.872 0% 2(LRS) 181611.0 -305208 (2000.0) SSC18129-3053 17.450 86.000 23.850 5.872 181612.3 -305208 (2000.0) PK1-6.2 181612.5 -305208 (2000.0) ESO457-PN2 181612.2 -305207 (2000.0) 1094 TYC7392.886.1 181612.2 -305207 (2000.0) 1094H HIP089535 plx=8.93(6.04) The first star is "relatively bright" in 2MASS, while the second star is saturated. What do you think? Regards, Taichi Kato