4 Known Be stars

The field of NGC663 is one of the most populous as far as Be stars are concerned. In the following discussion of Be stars in this open cluster, we shall confine ourselves to the 30$^\prime$ $\times$30$^\prime$ area shown in Fig. 1.

The first Be star discovered in this area was MWC428 = BD+60$^{\rm o}$325 (Merrill & Burwell 1943). A few years later, the next four Be stars: MWC698 = BD+60$^{\rm o}$332A, MWC700 = BD+60$^{\rm o}$340, AS42 = BD+60$^{\rm o}$341, and AS43 = BD+60$^{\rm o}$343B were found by the same authors (Merrill & Burwell 1949, 1950). Since subsequent observations did not detect emission in MWC700 (known also as Sanduleak 11), its Be nature is not certain. As was pointed out by Sanduleak (1979), it could happen that the BD number was incorrectly assigned by Merrill & Burwell (1949) and the star is identical with AS42.

González & González (1954) were the first to show that the cluster contains a large number of Be stars. They found 13 new stars of this type in the area under investigation. Subsequent studies (Dolidze 1975; Schild & Romanishin 1976; Coyne et al. 1978; MacConnell & Coyne 1983; Sanduleak 1990) added seven more stars, increasing the number of certain Be stars in NGC663 to 24. These stars are listed in the compilation of Kohoutek & Wehmeyer (1997).

Sanduleak (1979) has provided a list of 27 Be stars in NGC663, extending it by two objects in a subsequent paper (Sanduleak 1990). Since the numbers from Sanduleak's lists are widely used in the literature, we shall also refer to these stars preceding the number with "Sanduleak''. We now know, however, that not all Sanduleak's stars are still considered to be Be stars. Sanduleak 7, 18, and 19, announced to be Be stars by Coyne et al. (1978), appeared to be non-emission stars after revision (MacConnell et al. 1983). In addition, two other stars, Sanduleak 15 and 24, were found to have doubtful or very weak emission (Schild & Romanishin 1976; Voight 1965, respectively). Later observations (Sanduleak 1979, 1990; Torrejón et al. 1997; this paper) did not reveal emission in these stars either. Thus, only 23 stars with Sanduleak's numbers should be considered as certain Be stars and one, Sanduleak 11, as a probable Be star. We list these stars in Table 1. This table includes also five other emission-line stars: four new Be stars we discovered in the P field and star GG90 = D01+030 (see caption of Table 1 for designations) which probably is not a member, but is situated in the field shown in Fig. 1.

 

 

Table 1: List of Be stars in the 30$^\prime$ $\times$ 30$^\prime$field around NGC663. The columns are: (1), Sanduleak (1979, 1990) number, (2), Wallenquist (1929) number, (3), Kohoutek & Wehmeyer (1997) number, (4) and (5), X and Y coordinate in Fig. 2, (6), right ascension (epoch 2000.0, in hours, minutes, and seconds), (7), declination (epoch 2000.0, in degrees, arcmin and arcsec), (8), $R_{\rm C}$ magnitude (in mag), (9), $\alpha$ index (in mag), (10), other designations, "MWC'' and "AS'' precede numbers taken from papers of Merrill & Burwell (1943, 1949, 1950), "GG'', from González & González (1954), "D'', from Dolidze (1975), "VES'', from Coyne et al. (1978). Stars are listed in order of increasing right ascension.

S	W	HBH	X	Y	Right Asc.	Decl.	$R_{\rm C}$	$\alpha$	Other designations
(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
--	240	--	1056.6	309.1	1 45 11.65	+61 10 22.4	12.972	2.034	new Be star
1	243	6210-32	990.8	638.9	1 45 18.02	+61 06 55.9	9.902	1.463	BD+60$^{\rm o}$325, MWC428, D01+028
--	417	--	--	--	1 45 18.31	+60 58 09.2	--	--	GG90, D01+030
2	210	6210-54	759.9	544.1	1 45 37.77	+61 07 59.2	12.054	1.330	GG93, VES610, D01+031
3	130	--	727.3	65.1	1 45 39.63	+61 12 59.6	12.094	1.388	GG94, VES611
4	170	--	657.6	415.8	1 45 46.35	+61 09 20.9	11.771	1.977	GG95
--	128	--	622.8	-259.1	1 45 47.85	+61 16 23.6	13.122	1.949	new Be star
5	93	6210-56	537.6	91.8	1 45 56.07	+61 12 45.3	11.585	1.444	GG97, VES613
6	92	6210-57	500.6	92.2	1 45 59.27	+61 12 45.6	10.230	1.982	BD+60$^{\rm o}$332A, MWC698, VES614
28	84	6210-34	463.4	-125.1	1 46 02.03	+61 15 02.1	13.535	1.333
8	53	6210-15	419.8	8.5	1 46 06.09	+61 13 39.1	11.115	1.388	BD+60$^{\rm o}$333B, VES616
29	51	6210-73	328.6	3.3	1 46 13.99	+61 13 43.8	12.846	1.820
9	10	6210-31	255.8	-55.6	1 46 20.19	+61 14 21.6	11.442	1.741	GG98, VES617
--	61	--	215.7	304.1	1 46 24.37	+61 10 37.3	13.159	1.610	new Be star
13	141	6210-13	194.0	585.1	1 46 26.80	+61 07 41.8	10.197	1.341	BD+60$^{\rm o}$341, AS42, VES619, D01+033
10	8	--	178.8	-37.1	1 46 26.87	+61 14 11.2	11.905	1.999	GG99
11	107	--	186.3	361.3	1 46 27.02	+61 10 02.0	9.892	2.130	BD+60$^{\rm o}$340, MWC700
12	21	--	174.1	132.2	1 46 27.64	+61 12 25.5	10.341	1.725
14	6	6210-36	135.1	-64.9	1 46 30.60	+61 14 29.3	11.656	1.446	VES620
16	39	--	75.7	-189.1	1 46 35.49	+61 15 48.0	9.851	1.680	BD+60$^{\rm o}$343B, AS43, GG102
17	2	6210-14	79.9	16.6	1 46 35.57	+61 13 39.2	11.857	1.374	GG101
20	288	6210-59	--	--	1 46 57.53	+61 01 40.4	--	--	GG103
21	121	6210-51	-194.5	134.2	1 46 59.55	+61 12 29.8	13.012	1.565	VES624
22	194	6210-50	-218.3	-720.0	1 47 00.17	+61 21 23.7	11.039	1.837	GG104, VES625
23	124	6210-33	-252.3	-349.0	1 47 03.70	+61 17 32.2	12.072	2.050	D01-034
--	151	--	-402.9	61.2	1 47 17.46	+61 13 18.2	13.870	1.859	new Be star
25	222	6210-35	-501.4	499.3	1 47 26.72	+61 08 44.8	11.264	1.963	GG108, VES628
26	224	6210-25	-663.8	-419.7	1 47 39.34	+61 18 20.7	11.908	1.426	GG109, VES630, D01+036
27	297	6210-26	--	--	1 48 23.04	+61 15 53.2	--	--	GG110