COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS NUMBER 514 Konkoly Observatory Budapest 1971 February 8 NEW FLARE STARS IN THE PLEIADES OBSERVED AT ASIAGO FROM SEPTEMBER 1969 TO FEBRUARY 1970 The systematic searching of flare stars in the Pleiades which is still carried out at the Astrophysical Observatory of Asiago, has brought, in the fall and winter 1969-70, to the discovery of twenty-one flares and sixteen new flare stars. One-hundred and sixty plates (Kodak 103a-O or Oa-O, without filter), each with five successive exposures of five to eight minutes, covering a total time of observation of 93h43m, have been taken with the 67-90-215cm Schmidt telescope of Asiago. In Table I the flares are numbered from 32 to 52. Flares 1-13 have been published in a precedent paper by Rosino (Asiago Co. 189, 1966) and flares 14-31 in a paper by Rosino and Pigatto (Asiago Co. 231, 1969). Circumstances of the flares and identification charts will be reported in a forthcoming paper (Mem.Soc.Astr.Ital. Vol. XLI, No. 4). The Table I gives coordinates, pg magnitudes at maximum and normal minimum, date of the flare and Catalogue number of the corresponding star when available. Most of the flare stars have an infrared (Kodak IN hypersens. + RG5) magnitude from 1.5 to 2.5 brighter than the blue. It must be observed that, while the majority of the flare stars in the Pleiades, including those with large amplitude, have a time of decline not longer than 20-40 minutes or even less, we have Pound two stars (No. 22 of the precedent list, corresponding to H 138) and No. 48 of Table I which have shown flares having a time of decline of several hours. We report here the circumstances of the flare No. 48, observed on Dec. 2, 1969: -------------------------------------------------------------- Flare No.48 UT 19h41m 13.3pg 20h42m 14.7 21h44m15.35 -------------------------------------------------------------- 49 13.5 50 14.8 57 15.45 57 13.7 58 15.0 22 05 15.6 20 05 14.0 21 12 15.1 13 15.6 13 14.0 20 15.1 21 15.6 26 14.3 28 15.2 29 15.6 34 14.6 36 15.3 45 15.9 53 15.9 -------------------------------------------------------------- The star is very weak in blue (m_pg 19) and even in infrared. TABLE I - New Flares in the Pleiades Field observed at Asiago in 1969-70. ----------------------------------------------------------- 1900.0 Magnitudes Date Ident. N RA D. (pg) (1969-70) ----------------------------------------------------------- 32 3h36m 5" +22d37.9' 13.3-18: ? Sep 11 33 40 54 24 54.3 16.8-17.5 " 15 34 43 3 24 35.7 15.5-19: " 16 35 35 4 22 01.6 14.2-17.2 " 21 36 49 54 25 00.9 16.6-19: Oct 4 37 50 15 25 12.1 15.7-(18 " 10 38 39 16 22 44.2 15.7-18: " 12 39 41 42 24 09.1 16.1-19: " 14 40 41 2 22 56.6 15.3-16.5 " 15 41 43 45 24 00.8 14.3-15.7 " 16 HII 2411 42 34 10 24 05.4 15.5-18: " 17 43 34 34 24 49.3 15.1-19: " 17 Haro 102 44 44 00 25 05.8 13.2-14.7 " 19 " 108 45 43 19 23 45.5 13.7-16.5? " 19 46 49 42 22 30.8 14.8-16.1 " 21 47 39 52 25 33.0 14.9-17.0 Dec 1 48 42 15 29 1.8 13.3-19: " 2 49 41 08 23 18.4 14.8-16.4 " 29 HII 1286 Haro 16 50 45 56 23 45.1 13.3-18.5: Jan 1 51 43 45 24 00.8 14.5-15.5 Feb 3 HII 2411 52 31 58 22 22.3 14.5-(17.5 " 3 ----------------------------------------------------------- January, 1971. L. PIGATTO, L. ROSINO Astrophysical Observatory of Asiago