COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 3573 Konkoly Observatory Budapest 11 March 1991 HU ISSN 0374 - 0676 NEW VARIABLE STARS IN THE FIELD OF IC1805 The systematic photographic search of variable stars, in blue and infrared radiation, in 5 fields of some 25 square degrees each (Maffei 1975, 1977) has been continued in a field centered on the coordinates (1950.0) alpha=2h40m; delta= +60d30', with the Schmidt telescope of 65/90 cm at the Asiago Astrophysical Observatory. From 29th Sept. to 2nd Oct. 1975 and from 25th Dec. 1984 to 25th Jan. 1985, 74 I-N (Hypers.) + RG5 and 74 103a-O +GG13 or without filter were collected. The examination of these plates leads to the discovery of 35 new variable stars. The plates were compared by means of the blink microscope at the Asiago Observatory and with the positive - negative method. The main characteristics of the 35 variables are listed in Table I. The numeration of the variables, characterized with the prefix M, continues the one started in the field of M 16-M 17 (Maffei 1975, 1977). The positions and the photometric calibration were obtained by means of the photometer Sartorius of the Specola Vaticana at Castelgandolfo. The calibration was based on the photometric sequences published by Moffat and Vogt (1974). Table I. Previsional RA DEC Type m_I m_B Period Epoch Name (1950.0) max min max min days JD 24... M 278 2h41m51s 62d53' M 12.3 15.4 (1) 311 41273 M 279 37 26 62 31 SR 13.2 16.0 M 280 31 29 59 45 SR 13.2 15.4 465: M 281 47 50 59 14 M 12.2 15.5 189.5 41978 M 282 43 40 57 56 M 12.3 15.9 420 42086 M 283 25 25 60 17 M 11.4 14.5 273 41980 M 284 46 57 58 16 M 12.9 15.7 359 40127 M 285 17 54 60 20 M 12.8 15.4 228 41076 M 286 19 42 59 24 SR 14.1 <16.5 M 284 27 11 62 32 M 7.4 10.4 14.0 <17.4 552 46076 M 288 32 42 59 10 E 12.9 14.0 11.7 16.0 M 289 36 33 63 14 L 12.1 12.9 (1) M 290 24 19 61 56 L 13.3 14.3 18.4 20.0 M 291 56 41 61 25 E: 12.2 13.2 19.0 19.3 M 292 22 15 59 24 L 12.8 13.6 M 293 56 54 59 31 L 10.8 11.8 19.0 19.4 M 294 32 46 63 24 I: 14.1 16.4 M 295 33 38 61 48 L 11.1 12.1 M 296 47 0S 61 27 M 10.3 12.0 17.2 19.1 166.5 40626 M 297 35 28 61 51 I 12.8 13.8 14.0 14.5 M 298 35 09 58 50 I 10.5 11.3 16.5 18.0 M 299 20 50 59 11 SR 9.4 10.7 15.0 17.4 M 300 50 59 60 16 I 8.8 9.1 14.1 15.1 M 301 24 01 60 37 I (2) 14.6 15.8 M 302 37 21 62 22 I 14.3 14.9 17.2 18.4 M 303 35 17 59 31 I 11.7 12.9 13.2 14.1 M 304 43 51 62 30 E 12.9 13.9 14.9 16.2 M 305 55 16 61 02 I 13.1 13.7 16.8 18.1 M 306 31 27 62 59 I 10.1 10.8 15.6 16.6 M 307 41 00 61 52 SR 9.8 10.5 17.7 18.8 373: M 308 42 07 58 10 I 15.8 16.3 17.6 18.5 M 309 41 50 60 26 I 14.4 15.2 16.9 17.7 M 310 29 22 58 12 I 15.7 15.9 16.1 18.0 M 311 18 29 60 57 SR: (2) 14.1 15.2 M 312 34 51 58 37 L 15.6 16.1 16.8 17.7 (1) Visible on a few plates (2) Overexposed on all plates The identification charts, most of the light curves and a detailed account, will be published in a more extensive work. During this research a burst of star near the galaxy Maffei 2 was observed. This observation also will be published and discussed in a following work. Of the 35 new variables, 8 have been classified as Mira type stars and 6 as SR. Before this research 4 Mira and 4 SR were known in the field. This result confirms the increase of the number of long-period variable stars when the observations are made by means of the infrared technique. However in this region (galactic anti-center) the increase is not so dramatic as in the field of M 16 - M 17 neither so remarkable as in that of Gamma Cygni. Many thanks are due to Fth. G. V. Coyne, Director of the Specola Vaticana for the use of the photometer Sartorius and for the kind hospitality, Vania Gasperoni - Paolo Maffei - Gino Tosti Cattedra di Astrofisica Universita di Perugia, Italia References: Maffei P., 1975, Inf. Bull. Var. Stars No. 985 Maffei P., 1977, Inf. Bull. Var. Stars No. 1302 Moffat A.F.J. and Vogt N.J., 1974, Veroff. Astr. Inst. Bochum No. 2 [BIBCODE 1974VeBoc...2....1M ]