COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 4057 Konkoly Observatory Budapest 1 August 1994 HU ISSN 0374 - 0676 PHOTOMETRY OF STARS IN THE FIELD OF AQ AURIGAE AQ Aurigae (=IRAS 05031+3519 = GSC 2397-0319) is a poorly-studied, cool Mira with a period of about 335 days. Maxima are as bright as 8.5m while minima are fainter than 14m. The spectral type is in the range M6.5 to M7 according to Nassau & Blanco (1954) and Cameron & Nassau (1956). The variable was added to the program of the AAVSO in 1970. However, the comparison stars on the preliminary chart had magnitudes based mostly on eye-estimates. At the request of Charles Scovil of the AAVSO, I have made photoelectric observations of several stars in the field. Table 1. Photometry of Stars in the Field of AQ Aurigae Name RA (2000) Dec (2000) V b - y n spec Remarks h m s d ' " AQ Aur 5 06 30.3 +35 23 16 11.135 1.814 M7 (1) 11.113 1.832 (2) HD 32673 5 06 29.9 +35 33 45 7.794 0.427 2 G0 (3) 007 010 HD 32682 5 06 31.7 +35 30 47 8.104 0.297 2 A0 000 001 HD 280493 5 07 17.0 +35 41 18 9.640 0.397 1 B3e (4) HD 280499 5 06 37.3 +35 31 12 9.806 0.442 2 F8 002 001 HD 280494 5 06 50.5 +35 37 49 9.907 0.313 1 A2 HD 280498 5 05 43.4 +35 31 12 10.138 0.373 1 B2e (5) HD 280500 5 06 35.1 +35 17 47 10.161 0.348 2 B3 (6) 010 016 HD 280501 5 07 26.9 +35 14 58 10.182 0.490 1 F8 GSC 2397-1095 5 06 51.5 +35 23 45 11.360 1.005 2 006 018 GSC 2397-0760 5 06 55.8 +35 20 34 12.176 1.079 2 .014 .018 GSC 2397-0953 5 06 36.4 +35 23 36 13.242 1.139 2 009 035 Remarks: (1) - = GSC 2397-0319. Observation on 1993 Dec 5.39 UT. (2) - observation on 1993 Dec 7.35 UT. (3) - V = 7.799, b - y = 0.437 (Olsen 1983). (4) - = LS V + 35 8. (5) - = LS V + 35 6. (6) - = LS V + 35 7. [FIGURE 1] Figure 1. The field of AQ Aurigae showing stars from the GSC. V magnitudes are indicated to the nearest tenth with the decimal point omitted. I observed the stars using the Lowell 53cm photometric telescope on four nights: 5, 7, 8, & 9 December 1993 UT. Stromgren y and b filters were used through either a 29- or 49-arcsec diaphragm. Each observation consisted of at least three 10s integrations on `star' and two 10s integrations on 'sky', with greater numbers for stars fainter than about 9.0m. The standard star set was identical to that used for the field around VX Tauri (Skiff 1994), and so the results for these will not be repeated here. Results for the stars near AQ Aurigae are shown in Table 1, listed in order of decreasing brightness. Measures on two nights of AQ Aurigae itself are given in the first entry. The comparison stars are identified by HD or GSC number, with positions from the PPM, GSC, or other sources via SIMBAD; SIMBAD is also the source for spectral types from the literature. The second line of each entry shows the standard deviation of the means for stars observed on two nights. The two Be stars, HD 280493 and HD 280498, were found to exhibit Halpha emission by Stephenson & Sanduleak (1977). These may be slightly variable, but probably only with small amplitude. For the convenience of observers, a chart derived from the GSC is shown in Figure 1. The comparison stars are indicated by their V magnitudes rounded to the nearest tenth (decimal point omitted) in the style of visual variable-star charts. Preparation of this report was facilitated by the use of SIMBAD, maintained by the Centre de Donnees astronomiques, Strasbourg, France. Brian A. SKIFF Lowell Observatory 1400 West Mars Hill Road Flagstaff AZ 86001-4499 Internet: base@lowell.edu References: Cameron, D. and Nassau, J. J., 1956, Astrophys. J., 124, 346 [BIBCODE 1956ApJ...124..346C ] Nassau, J. J., and Blanco, V. M., 1954, Astrophys. J., 120, 118 [BIBCODE 1954ApJ...120..118N ] Olsen, E. H., 1983, Astron. Astrophys. Suppl. Ser., 54, 55 [BIBCODE 1983A&AS...54...55O ] Skiff, B. A., 1994, Inf. Bull. Var. Stars, No. 4056 Stephenson, C. B. and Sanduleak, N., 1977, Astrophys. J., Suppl. Ser., 33, 459 [BIBCODE 1977ApJS...33..459S ]