COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 3701 Konkoly Observatory Budapest 11 March 1992 HU ISSN 0374 - 0676 NOTES ON THE IDENTIFICATION OF NINE VARIABLE STARS In the course of preparing finder charts for the Variable Star Section of the Royal Astronomical Society of New Zealand I have noted a number of variables whose data, as given in the New Catalogue of Suspected Variable Stars (Kholopov et al., 1982), and the General Catalogue of Variable Stars (Kholopov et al., 1985), appears to be in error. Generally speaking, coordinates are most frequently at fault. A very useful source of reliable coordinates for faint stars over the whole celestial sphere is the Guide Star Catalogue (GSC) created for the Hubble Space Telescope. The GSC reaches fifteenth magnitude stars in many sky regions, and therefore includes many variables which are too faint to be listed in other general star catalogues. All of the variables discussed in this paper (with the exception of V449 Lyr) have been identified in the GSC. The bright variables QV Pup, GS Vel, NSV 2954 and NSV 5444 were easily found by inspecting a computer print-out of a small sky window centred on the variable: the faint stars AE Pup, AF Pup, AK Vel and AM Vel lie in rich Milky Way fields and their identities have been confirmed beyond doubt by plotting small charts from the GSC and matching them with the original published finder charts. Table 1 lists the main data extracted from the GSC. Additional notes for most of the variables are given below. -------------------------------------------------------------------------- Table 1: IDENTIFICATIONS AND COORDINATES FOR NINE VARIABLE STARS. GSC Mean Position (J2000) STAR GSC No. Mag(J) h m s d ' " N AE Pup 7667-3465 13.64 8 5 51.25 -42 30 38.3 3 AF Pup 7672-129 14.13 8 13 38.75 -43 7 46.4 3 AK Vel 8136-2430 12.99 8 5 53.88 -46 36 58.1 1 AM Vel 8154-114 13.96 8 35 37.03 -47 45 33.9 3 QV Pup 6565-1227* 13.33 7 55 13.30 -29 39 7.2 2 6565-3198* 9.55 GS Vel 8622-2228 8.96 10 45 30.86 -56 36 42.5 2 NSV 2954 7074-1253 7.53 6 30 0.64 -31 10 26.3 1 NSV 5444 8229-2057 9.40 12 4 5.31 -45 56 14.4 1 V449 Lyr ---- -- 19 7 37 44 0.2 -- -------------------------------------------------------------------------- N = number of GSC plate measurements. Note: * For QV Pup, two GSC stars with nearly identical coordinates, differing only 0.03s in R.A. and 0.6" in declination. Assumed to be one and the same object. -------------------------------------------------------------------------- AE Pup, AF Pup, AK Vel, AM Vel. These four stars were first studied by Zagar (1935) who also published finder charts. The published coordinates for all of these stars are in error, the declinations being out by several minutes of arc. AE Pup : The GSC lists three close companions. They are mag R.A. (J2000) Dec.(J2000) GSC 7667-3073 14.01 8h 05m 50.03s -42d 30' 08.5" GSC 7667-3659 14.66 8 05 49.48 -42 30 09.6 GSC 7667-3979 15.01 8 05 50.43 -42 30 35.7 All of these values are means of three plate measurements AK Vel : The error in the position was noted on the VSS, RASNZ chart for BL Vel (chart 828, Bateson and Morel, 1985). The corrected position has not yet appeared in the 4th edition of the GCVS. AM Vel : A somewhat brighter star (GSC 8154-445, mag. 12.1) lies 22" of arc to the SW. The error in the position of AM Vel was noted on the VSS, RASNZ chart for BB Vel (chart 367, Bateson et al., 1976), and the corrected position now appears in the 4th edition of the GCVS. QV Pup : This variable carbon star has been identified variously as CoD-29d5141 (GCVS, 4th ed.) and CoD-29d5142 (Stephenson, 1973). These two CoD stars lie only 1.5' apart on a line which is nearly North-South. Errors in the declinations of both CoD stars are responsible for the ambiguous identification. Comparison of blue and yellow light plates show the southern star, CoD-29 5142, to be red, and the correct identification. Coordinates (1950): 7h 53m 13.0s -29d 31.2'. GS Vel : The photometric variability of this star was first noted by Humphries et al. (1972), where their UBV measurements varied from 9.21 to 9.45 in V. They identified this M2 Ib supergiant by a CoD number, CD-55d3622. This DM number corresponds, however, to HDE 301021, of spectral type F8, and hence appears to be incorrect. The correct identification appears to be a nearby star HDE 301022 (M0) = CPD-55d3815. This star is not in the CoD. Correct coordinates for GS Vel = CPD-55 3815 are (1875) 10h 40m 29.5s -55d 57.4' (CPD) (1950) 10 43 30 -56 21.0 Finder charts. GS Vel is plotted incorrectly on VSS, RASNZ chart 554 (Bateson et al., 1981), but the correct identification is made on chart 869 (Bateson and Morel, 1986). NSV 2954 : There is a misprint in the paper by Hawarden (1975) where the star's variability was first suggested. The star is stated to be in the vicinity of the cluster NGC 2243 (R.A.=6h 28.7m Dec.=-31d 16'). The star number cited is HD 45095, but this star is far from the cluster and its spectral type (G2 V) does not match the colours published by Hawarden. The correct identification is probably HD 46095 = SAO 196879 which lies only 8' from NGC 2243 and has suitable spectral type (A0 V) and magnitudes (7.4v, 7.4p) to match the known colours. Coordinates (1950): 6h 28m 7.0s -31d 08' 21" (SAO). NSV 5444 : Is star .35 in standard region E5. This star is HD 104806 = CoD-45d7506 = CPD-45d5761. Declination in NSV is in error, and should be -45d39.5'. NSV position apparently refers to CPD-45d5762, a faint non-HD star 1'54" due S of the HD star. V449 Lyr : Announced by Romano (1972). Range 12.5 - 16.0p. Lies quite close to MV Lyr, for which a finder chart appeared in AAVSO Circular 47 (1974). V449 Lyr is situated slightly south-west of star '121', but is not plotted on the chart, which appears to reach thirteenth magnitude, at least. V449 Lyr is not listed in the GSC, whose limiting magnitude is about 14.4V in this region. Possibly the published maximum magnitude is too bright, by as much as two magnitudes. The published position needs revision. An improved, but still approximate position is given in Table 1. The identifications and coordinates found for these variables in the GSC are summarized in Table 1. The meanings of most column headings are self-evident. Column 3 gives mean values of GSC magnitudes. All of the southern GSC magnitudes are derived from plates of the UK SERC J Survey (blue-green sensitive). Column 5 gives the number of plate measurements, N. I thank Mr Albert F. Jones of Stoke, Nelson, New Zealand for kindly furnishing an early number of IBVS. MATI MOREL 18 Elizabeth Cook Drive, Rankin Park NSW 2287 Australia References: AAVSO Circular: 1974, September, No.47, p.4. Bateson, F. M., Morel, M., Winnett, R.: 1976, CHARTS FOR SOUTHERN VARIABLES, Series 9, Publ. by Astronomical Research Ltd., Tauranga, NZ. [BIBCODE 1977csvs.book.....B ] Bateson, F. M., Morel, M., Sumner, B., Winnett, R.: 1981, ibid, Series 13, Publ. by Astronomical Research Ltd., Tauranga, NZ. [BIBCODE 1981csvs.book.....B ] Bateson, F. M., Morel, M.: 1985, ibid, Series 18, Publ. by Astronomical Research Ltd., Tauranga, NZ. [BIBCODE 1985csvs.book.....B ] Bateson, F.M., Morel, M.: 1986, ibid, Series 19, Publ. by Astronomical Research Ltd., Tauranga, NZ. [BIBCODE 1986csvs.book.....B ] Hawarden, T.G.: 1975, Mon. Not. R. ast. Soc., 173, 801. [BIBCODE 1975MNRAS.173..801H ] Humphreys, R.M., Strecker, D.W., Ney, E.P.: 1972, Astrophys. J., 172, 75. [BIBCODE 1972ApJ...172...75H ] Kholopov, P.N. (ed.): 1982, New Catalogue of Suspected Variable Stars. Nauka, Moscow. [BIBCODE 1982ncss.book.....K ] Kholopov, P.N. (ed.): 1985, General Catalogue of Variable Stars. 4th ed., Nauka, Moscow. Romano, G.: 1972, IBVS No. 645. Stephenson, C.B.: 1973, General Catalogue of Cool Carbon Stars. Publ. Warner and Swasey Observatory, 1, 4. [BIBCODE 1973PW&SO....1...1S ] Guide Star Catalogue: 1989, The Space Telescope Science Institute, Baltimore, Maryland, USA. On CD-ROM. Zagar, F.: 1935, BAN, 7, 275. [BIBCODE 1935BAN.....7..275Z ] [DATAFILE 1]