2 Observations and reductions

All photometric observations of NGC7419 were carried out at the Biaków Observatory of the Wrocaw University using the 60-cm reflecting telescope equipped with a 576 $\times$ 384 pixels CCD camera covering a 6$^\prime$ $\times$ 4$^\prime$ field of view. In order to detect emission in the H$\alpha$ line, we used two interference filters centred on this line with the full width at half maximum of 20 and 3 nm for wide and narrow H$\alpha$ filter, respectively.

The H$\alpha$ observations of NGC7419 were carried out on a single night of November 15, 1999. We took 11 frames in the wide H$\alpha$ filter and 8 frames in the narrow one with the total integration time of 6600 and 18500 s, respectively. The H$\alpha$ observations were supplemented by observations of the same field through Cousins $R_{\rm C}$ and $I_{\rm C}$filters made on November 15, 1999 ($R_{\rm C}$, a single 600-s frame) and September 17, 1999 and January 6, 2000 ($I_{\rm C}$, twenty 120-s frames). These observations were transformed to the standard system using the photometry of Bhatt et al. (1993), tied to the Landolt (1983) standards. We do not give here the details of transformations and present the photometry in the graphical form only. They are, however, available from the authors upon request. The resulting colour-magnitude diagram (CMD) shown in Fig. 4 is used for distinguishing some of the non-members. All stars which were detected both in the $R_{\rm C}$ and $I_{\rm C}$-filter frames are shown in Fig. 1.

Figure 1: Schematic view of our 6$^\prime$ $\times$ 4$^\prime$ field in NGC7419. The diameters of the circles were chosen to resemble the cluster appearance as seen through the $R_{\rm C}$ filter. All emission-line objects listed in Table 1 are labeled with numbers from B94. North is up, east to the left

Figure 2: The $\alpha$ index (in mag) for 107 stars brighter than $R_{\rm C}$ = 16.1 mag, plotted as a function of $R_{\rm C}$. Non-members are shown with crosses, cluster members showing H$\alpha$ emission, with open circles (the circles are double for new Be stars), remaining stars, with filled circles. The dashed line corresponds to the expected value of $\alpha$ for zero equivalent width of the H$\alpha$ line

 

Table 1: Stars in NGC7419 showing H$\alpha$ emission. The columns are: (1): Beauchamp et al. (1994) number, (2): Bhatt et al. (1993) number, E precedes the number of a star in the eastern region of the cluster, W, a star in the western region, (3): Kohoutek & Wehmeyer (1997) number, (4) and (5): X and Y coordinate in Fig. 1, (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): $(R-I)_{\rm C}$ colour index (in mag), (10): $\alpha$ index (in mag), (11): remarks

BMD	BPMM	HBH	X	Y	Right Asc.	Decl.	$R_{\rm C}$	$(R-I)_{\rm C}$	$\alpha$	Remarks
(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)	(11)
232	W12	--	489.5	235.4	22 54 07.10	+60 48 17.3	15.51	1.33	1.417 $\pm$ 0.019	new
239	W14	6206-14	479.9	35.5	22 54 07.55	+60 50 22.7	13.90	1.31	1.291 $\pm$ 0.008
290	W23	--	452.0	105.8	22 54 10.05	+60 49 38.9	14.84	1.18	2.064 $\pm$ 0.031	D22-117:
340	W33	--	428.1	210.6	22 54 12.29	+60 48 33.6	15.41	1.20	1.982 $\pm$ 0.033	new
351	W37	--	420.8	58.5	22 54 12.63	+60 50 09.0	14.70	1.15	1.756 $\pm$ 0.015	new
389	W45	6206-13	402.8	201.7	22 54 14.42	+60 48 39.5	12.64	1.14	1.505 $\pm$ 0.005	B1-2I:e (B94)
417	--	--	390.1	88.9	22 54 15.30	+60 49 50.4	13.14	1.06	2.064 $\pm$ 0.008	new
427	W54	--	387.4	282.0	22 54 15.89	+60 47 49.4	14.03	1.23	1.440 $\pm$ 0.008	new
451	W58	--	376.6	228.9	22 54 16.71	+60 48 22.8	15.02	1.08	1.946 $\pm$ 0.019	new
458	W60	--	375.0	236.1	22 54 16.85	+60 48 18.3	14.85	1.12	1.788 $\pm$ 0.016	new
504	E10	--	361.6	174.0	22 54 17.88	+60 48 57.4	14.08	1.11	1.372 $\pm$ 0.008	new
551	E20	--	352.9	243.3	22 54 18.75	+60 48 14.1	15.45	1.08	1.958 $\pm$ 0.026	new
582	E25	--	341.7	183.7	22 54 19.59	+60 48 51.6	14.63	1.02	1.352 $\pm$ 0.011	new
585	E26	6206-12	341.9	208.4	22 54 19.62	+60 48 36.1	13.44	1.02	1.985 $\pm$ 0.008
620	E30	--	330.1	87.1	22 54 20.41	+60 49 52.3	13.12	1.14	1.358 $\pm$ 0.006	new
621	E31	--	331.4	179.7	22 54 20.46	+60 48 54.3	13.93	1.12	2.053 $\pm$ 0.010	new
633	--	--	326.3	84.0	22 54 20.73	+60 49 54.3	16.04	1.10	1.476 $\pm$ 0.041	new
692	E50	6206-11	305.1	85.3	22 54 22.54	+60 49 53.7	13.05	1.15	1.443 $\pm$ 0.006
698	--	--	305.7	235.3	22 54 22.76	+60 48 19.7	15.04	1.04	1.975 $\pm$ 0.042	new
702	E53	6206-18	301.6	68.8	22 54 22.81	+60 50 04.1	13.15	1.13	1.607 $\pm$ 0.006
728	E57	6206-15	292.6	121.0	22 54 23.67	+60 49 31.5	14.78	1.01	1.355 $\pm$ 0.013
741	--	--	289.3	360.7	22 54 24.37	+60 47 01.3	16.08	1.21	1.475 $\pm$ 0.028	new
745	E61	6206-10	288.7	304.6	22 54 24.32	+60 47 36.5	15.39	1.18	1.256 $\pm$ 0.014
781	E68	--	270.8	168.2	22 54 25.61	+60 49 02.3	12.89	1.09	1.467 $\pm$ 0.005	new, B1-2I: (B94)
795	E71	6206-09	268.3	270.9	22 54 26.01	+60 47 57.9	15.02	1.17	1.399 $\pm$ 0.015
815	E75	--	260.7	162.7	22 54 26.46	+60 49 05.8	14.58	1.02	1.920 $\pm$ 0.022	new
831	E82	6206-08	253.8	183.9	22 54 27.08	+60 48 52.6	13.78	1.03	1.280 $\pm$ 0.007
884	E90	6206-07	228.1	158.8	22 54 29.24	+60 49 08.7	14.64	1.07	1.403 $\pm$ 0.017
967	E100	6206-16	194.5	272.9	22 54 32.30	+60 47 57.6	14.62	1.07	2.151 $\pm$ 0.018
1076	--	6206-17	143.1	211.4	22 54 36.56	+60 48 36.9	13.21	1.15	1.381 $\pm$ 0.006	D22-124
1129	--	--	120.2	326.1	22 54 38.72	+60 47 25.3	12.98	1.06	2.115 $\pm$ 0.008	D22-125
950	E96	--	199.1	110.0	22 54 31.62	+60 49 39.7	10.65	2.95	1.969 $\pm$ 0.004	MY Cep
350	W36	--	422.0	101.9	22 54 12.60	+60 49 41.8	15.26	1.73	2.064 $\pm$ 0.042	non-member