1 RX J2112.7+5006 GD 394 = RE J211241+500619 2 RX J2133.9+4535 HD 205435 = HR 8252 = {rho} Cyg 6 RX J2106.0+5421 In ADS catalogue 8 RX J2130.8+4827 Member of NGC 7092, in ADS catalogue 10 RX J2124.7+4639 GSC-0359001727 merges objects A and B 11 RX J2117.3+5044 Our candidate was independently discovered by Lanning, H.H. and Meakes, M. (1994PASP..106...38L) in a search for faint UV-bright stars in the galactic plane. A finding chart may be found in their work. 12 RX J2135.9+4728 z = 0.025 13 RX J2102.6+4552 Chromospheric activity in HD 200560 was reported by Soderblom (1985AJ.....90.2103S). 15 RX J2055.3+5025 On the basis of its position outside the 90% confidence circle and weak Ca II H&K emission, star B is unlikely to contribute much to the X-ray source. The finding chart was extracted from the STSCI digitized sky survey. 23 RX J2100.1+4841 BD+48 3260 E = ADS 14531 E 26 RX J2107.3+5202 This star is an eclipsing binary of the Algol type with an orbital period of 2.3467 days. 30 RX J2120.4+4733 = ADS 14886 AB 37 RX J2103.4+5021 Ca H&K emission also visible in the high resolution spectrum of Strassmeier (1994A&AS..103..413S). 38 RX J2040.6+4859 = ADS 14161 A 43 RX J2130.1+4901 Candidate object 'B' coincides in position with star 2376 in the catalogue of stars in the region of the open cluster M39 compiled by Platais (1994, Cat. ). This M5Ve star lies far off the photometric sequence defined by Mohan and Sagar (1985MNRAS.213..337M) for this cluster and we conclude that object 'B' is a foreground star not related to the open cluster. Object 'A' would deserve follow-up observations. 51 RX J2132.5+4849 Candidates A and B are respectively stars 4522 and 4516 in the catalogue of stars in the region of the open cluster M39 compiled by Platais (1994). Our high and low resolution (not shown) spectra show that A is a G1 star and B is a K7 star. These spectral types are in agreement with the B-V indices listed in Platais (1994, Cat. ). Assuming that the two stars are on the main sequence implies a distance modulus incompatible with a membership to M39. Recent additional optical observations (not shown) indicate that the two brightest objects east of "B" (D and E not marked) are M stars with weak H{alpha} emission. The X-ray source could result from the combined coronal emission of several of the stars held in the error circle. 53 RX J2035.9+4900 The medium resolution spectrum of object 'A', the proposed optical counterpart, exhibits clear line doubling revealing the presence of a close binary. 58 RX J2109.9+4809 The UBV photometry reported by Young et al. (1976ApJ...209..882Y) suggests a spectral type slightly later than A5 for SAO 50523. 65 RX J2127.3+5121 Object A is GSC-0360200451 (V=11.92) and B is GSC-0360200459 (V=11.46). Optical coordinates and magnitudes recorded in Tables are those of B. 68 RX J2055.8+5044 X-ray position compatible with IRAS 20544+5033 74 RX J2128.4+4900 Star A (V=13.75; B-V=0.57; U-B=0.45) is number 889 in the catalog of objects in the direction of M39 by Platais (1994, Cat. ). 76 RX J2130.0+4740 Candidates A (V=11.98; B-V=1.09; U-B=0.68) and B (V=11.00; B-V=0.52; U-B=-0.10, spectral type F6) are respectively stars 2137 and 2189 in the catalog of objects in the region of M39 (Platais 1994, Cat. ). The colour indices of object A suggest a K4 spectral type with a distance modulus smaller than M39 whereas candidate B is likely to belong to the open cluster. 92 RX J2052.8+4723 X-ray position compatible with IRAS 20512+4712. 97 RX J2134.2+4911 Candidate A is number 5991 in the catalog of objects in the region of M39 (Platais 1994, Cat. ). Its red colours are compatible with A being a nearby M2-M6 star. Two other stars in Platais's list (5981 and 5999) fall inside the 90% confidence radius. UBV photometry suggests that these two objects are G type stars located behind M39 and are therefore less likely optical counterparts of the X-ray source. 103 RX J2114.1+4840 Object A is GSC-0359304712 (V=11.36) and Object B is GSC-0359304650 (V=13.61). The optical positions and magnitudes recorded in Tables are those of A. 105 RX J2122.6+4956 X-ray position compatible with IRAS 21209+4943. 108 RX J2126.9+4636 X-ray position compatible with IRAS 21252+4624 141 RX J2127.1+4801 A possible identification based on positional coincidence is star 173 in the catalogue of objects in the region of M39 (Platais 1994, Cat. ). 149 RX J2131.2+4812 The GSC entry closest to the X-ray position is star 3359 in the catalogue of objects in the region of M39 (Platais 1994, Cat. ). Its colour suggests a G2-G5 type and a distance compatible with a membership to M39. 152 RX J2130.8+4842 Star number 3016 of the catalog of objects in the region of M39 (Platais 1994, Cat. ) falls into the 90% confidence error circle. The UBV photometry is consistent with a K2-K5 dwarf in M39.