2003A&A...402..571H

Query : 2003A&A...402..571H

2003A&A...402..571H - Astronomy and Astrophysics, volume 402, 571-586 (2003/5-1)

An X-ray study of the open clusters NGC 2451 A and B.

HUENSCH M., WEIDNER C. and SCHMITT J.H.M.M.

Abstract (from CDS):

We have conducted a detailed study of the object NGC 2451, which actually consists of two different open clusters A and B along the same line of sight at 206pc and 370pc distance, respectively. Although belonging to the nearest clusters, they have not been much investigated until present due to strong contamination by field stars. ROSAT X-ray observations and optical UBVR photometry are used to identify cluster members by means of X-ray emission and colour-magnitude diagrams. The identified stars concentrate nicely around the expected main sequences in the colour-magnitude diagram at the distances derived from astrometric investigations. Altogether, 39 stars are identified as member candidates of the nearer cluster A, 49 stars as member candidates of the more distant cluster B, and 22 faint stars are probably members of either of the two clusters, but due to large errors it is not clear to which one they belong. Further 40 stars identified with X-ray sources are probably non-members. For the first time, the range of known probable cluster members of NGC 2451 A and B has been extended downwards the main sequence to stars of spectral class M. Isochrone fitting yields an age of 50 to 80Myrs for NGC 2451 A and ≃50Myrs for NGC 2451 B, consistent with the X-ray luminosity distribution functions, which are comparable to other clusters in the same age range. Except from the occurence of four flares, the stars of both clusters do not show strong long-term X-ray variability exceeding a factor 5 over a time span of 1 to 3 years.

Abstract Copyright: ∼

Journal keyword(s): stars: activity - stars: coronae - Hertzsprung-Russell (HR) and C-M diagrams - open clusters and associations: individual: NGC 2451 - X-rays: stars

VizieR on-line data: <Available at CDS (J/A+A/402/571): x-obs.dat sources.dat notes.dat tables.tex>

Nomenclature: Tables 3-10: [HWS2003] XNNN (Nos X1-X188).

Simbad objects: 154

goto Full paper

goto View the references in ADS

Number of rows : 154
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024 		#notes
1 [HWS2003] X4 X 07 42 10 -37 26.8   19.71 18.23     ~ 1 0
2 CD-37 3808 SB* 07 42 43.5631196040 -38 02 57.853243716   10.58 10.30     ~ 19 0
3 CD-37 3810 SB* 07 42 52.6278820440 -38 03 26.939706696   11.40 10.84     ~ 10 0
4 [HWS2003] X92 X 07 42 55 -37 57.9   19.09 17.98     ~ 1 0
5 NGC 2451A OpC 07 42 56.6 -38 15 50           ~ 129 0
6 Cl* NGC 2451 PKB 2609 * 07 43 00.5825501928 -37 57 30.073875624 13.070 12.958 12.332 11.940 11.542 ~ 14 0
7 2MASS J07430635-3809210 * 07 43 06.3504465096 -38 09 21.027337740 17.636 16.611 15.152 14.158 13.017 ~ 14 0
8 [HWS2003] X153 X 07 43 09 -38 10.8   15.93 15.00     ~ 1 0
9 [HWS2003] X13 X 07 43 12 -37 37.6   16.98 15.31     ~ 1 0
10 [HWS2003] X35 X 07 43 13 -37 47.4   17.08 15.70     ~ 1 0
11 Cl* NGC 2451 PKB 2262 * 07 43 19.5574177872 -38 05 37.165279416 14.138 13.923 13.163 12.720 12.272 ~ 9 0
12 2MASS J07432439-3756131 * 07 43 24.3932751096 -37 56 13.164186228   14.240 13.407 12.918 12.464 ~ 15 0
13 HD 62660 * 07 43 30.7002545520 -38 08 15.236574216   9.36 8.37     G8III/IV 17 0
14 HD 62712 * 07 43 42.9160399680 -38 12 06.767386272 5.76 6.24 6.40     B8IV 83 0
15 [HWS2003] X124 X 07 43 45 -38 03.9   21.94 20.25     ~ 1 0
16 CD-37 3823 * 07 43 49.3114344200 -37 53 44.407068114   11.049 10.627 10.198 9.890 ~ 15 0
17 CD-37 3825 * 07 43 49.7034312432 -37 58 00.765586812   10.025 9.855 9.736 9.682 A2V 16 0
18 2MASS J07435088-3807069 * 07 43 50.8821828072 -38 07 06.909736944   17.641 16.123 14.972 13.504 ~ 6 0
19 [HWS2003] X173 X 07 43 52 -38 16.3   16.39 14.89     ~ 1 0
20 Cl* NGC 2451 PKB 2275 * 07 43 54.3421982304 -38 00 02.736243468 13.632 13.150 12.309   11.373 ~ 20 0
21 2MASS J07435482-3746306 * 07 43 54.8190806304 -37 46 30.654136452 18.779 17.984 16.505 15.407 14.095 ~ 14 0
22 Cl* NGC 2451 PKB 6499 * 07 43 57.4904969784 -38 27 51.021105120   14.697 13.537     ~ 17 0
23 CPD-37 1516 * 07 43 58.3169968632 -37 37 24.714323904   12.443 11.826     ~ 3 0
24 HD 62782 * 07 44 02.7453774504 -38 08 32.975216736   9.59 8.63     G8III/IV 13 0
25 [HWS2003] X123 X 07 44 04 -38 03.8   17.98 16.81     ~ 1 0
26 UCAC4 261-020052 ** 07 44 06.864144 -37 59 22.13520   17.940 16.430 16.17   ~ 6 0
27 HD 62802 * 07 44 08.6021343576 -37 59 00.646755540 9.346 9.466 9.359 9.386 9.291 B9V 18 0
28 Cl* NGC 2451 AR 43 * 07 44 09.9169993368 -37 54 52.758286164   14.189 13.396 12.930 12.471 ~ 14 0
29 CD-37 3832 * 07 44 12.9763824312 -37 20 50.524095408   10.96 10.25     ~ 3 0
30 [HWS2003] X30 X 07 44 16 -37 46.0   14.21 13.15     ~ 2 0
31 [HWS2003] X34 X 07 44 17 -37 47.2   19.92 18.42     ~ 1 0
32 [HWS2003] X71 X 07 44 18 -37 54.3   20.20 18.62     ~ 1 0
33 [HWS2003] X52 X 07 44 18 -37 51.6   19.39 18.50     ~ 1 0
34 [HWS2003] X98 X 07 44 19 -37 58.9   16.56 15.53     ~ 1 0
35 2MASS J07441914-3800194 * 07 44 19.1430972024 -38 00 19.442444724   15.480 14.370     ~ 9 0
36 [HWS2003] X135 X 07 44 21 -38 06.0   13.97 12.60     ~ 1 0
37 Cl* NGC 2451 AR 52 * 07 44 22.5471138000 -37 52 55.540324236   13.915 13.148 12.725 12.293 ~ 17 0
38 [HWS2003] X26 X 07 44 23 -37 44.5   14.94 14.09     ~ 1 0
39 Cl* NGC 2451 PKB 1256 * 07 44 24.0633148008 -38 35 59.041061736   11.562 10.953     ~ 13 0
40 Cl* NGC 2451 PKB 2288 * 07 44 24.4317167400 -38 09 03.315004740   14.166 13.473     ~ 2 0
41 2MASS J07442606-3756592 * 07 44 26.0606879232 -37 56 59.269635348   19.86 18.34     ~ 7 0
42 HD 62875 * 07 44 27.5560200456 -37 39 48.038357664   8.27 8.31     B8V 33 0
43 HD 62876 * 07 44 28.0958555856 -37 59 15.806663916   8.698 8.576     A2V 29 0
44 Cl* NGC 2451 AR 57 * 07 44 29.2664776464 -37 46 44.288661900 13.539 13.459 12.780 12.387 11.989 ~ 16 0
45 NGC 2451B OpC 07 44 30.7 -37 57 14           ~ 96 0
46 NGC 2451 124 * 07 44 32.6877213504 -38 00 26.692051860   12.50 11.88     ~ 4 0
47 HD 62893 * 07 44 34.1830281624 -37 56 34.510493904   5.759 5.870     B8V 65 0
48 [HWS2003] X36 X 07 44 35 -37 47.5   19.33 17.62     ~ 1 0
49 [HWS2003] X121 X 07 44 36 -38 03.0   19.64 18.05     ~ 1 0
50 2MASS J07443639-3754018 * 07 44 36.3855229512 -37 54 01.848527892   14.245 13.444 12.994 12.520 ~ 13 0
51 2MASS J07443682-3754597 * 07 44 36.8237897832 -37 54 59.777526204   18.553 17.112 16.043 14.884 ~ 13 0
52 [HWS2003] X170 X 07 44 37 -38 14.5   20.44 19.25     ~ 1 0
53 [HWS2003] X44 X 07 44 37 -37 49.0   18.17 16.70     ~ 1 0
54 [HWS2003] X140 X 07 44 38 -38 06.2   19.86 18.59     ~ 1 0
55 [HWS2003] X58 X 07 44 38 -37 52.1   18.99 18.13     ~ 1 0
56 CD-37 3843 * 07 44 38.2952311464 -38 13 15.822526224   10.7 10.5     ~ 8 0
57 [HWS2003] X166 X 07 44 42 -38 13.5   19.31 18.24     ~ 1 0
58 [HWS2003] X79 X 07 44 42 -37 55.8   17.92 17.14     ~ 1 0
59 [HWS2003] X41 X 07 44 44 -37 48.1   19.77 18.06     ~ 1 0
60 [HWS2003] X164 X 07 44 46 -38 13.1   18.99 18.05     ~ 1 0
61 NGC 2451 8 * 07 44 47.1490491312 -38 11 55.525258788   14.64 13.95     ~ 2 0
62 CD-37 3848 * 07 44 47.9558779704 -38 14 38.499541980   11.84 11.60     ~ 3 0
63 2MASS J07444871-3805552 * 07 44 48.7227135864 -38 05 55.348856412   14.240 13.490     ~ 14 0
64 [HWS2003] X54 X 07 44 49 -37 51.6   17.15 16.73     ~ 1 0
65 [HWS2003] X38 X 07 44 49 -37 47.8   20.11 18.43     ~ 1 0
66 CD-37 3850 * 07 44 51.0399330576 -37 40 07.245190776   10.940 10.667 10.748   ~ 17 0
67 2MASS J07445137-3808013 * 07 44 51.3798985536 -38 08 01.411594800   14.704 13.768 13.231 12.751 ~ 14 0
68 CD-37 3853 * 07 44 56.1710075496 -38 00 13.589587332   10.3 9.8     ~ 8 0
69 HD 62974 ** 07 44 59.6805831138 -38 05 39.162239997   8.435 8.302     A3V 29 0
70 CPD-37 1549 * 07 45 00.6064353024 -38 00 01.552067064   12.18 11.68     ~ 7 0
71 CD-37 3859 * 07 45 01.6851326352 -38 02 20.161377996   10.508 10.059 9.817 9.614 ~ 18 0
72 NGC 2451 118 * 07 45 02.2035794352 -38 25 49.146130920   12.79 12.19     ~ 6 0
73 NGC 2451 51 * 07 45 02.4587733480 -38 14 52.965624588   13.06 12.39     ~ 6 0
74 Cl* NGC 2451 AR 95 SB* 07 45 02.6676609312 -38 01 52.258343376 13.142 13.184 12.495 12.098 11.744 ~ 15 0
75 NGC 2451 128 * 07 45 03.7467452256 -38 06 10.781221860   13.505 12.782 12.392 12.035 ~ 16 0
76 HD 62991 * 07 45 04.7720287128 -37 53 16.344632580 5.76 6.402 6.512     B2V 61 0
77 2MASS J07450486-3804286 * 07 45 04.8736963008 -38 04 28.665538716 19.862 19.186 17.688 16.439 14.910 ~ 12 0
78 [HWS2003] X83 X 07 45 05 -37 56.6   16.76 15.42     ~ 1 0
79 [HWS2003] X40 X 07 45 05 -37 48.1   16.87 15.49     ~ 2 0
80 [HWS2003] X67 X 07 45 08 -37 53.9   17.16 16.40     ~ 1 0
81 [HWS2003] X158 X 07 45 09 -38 12.2   17.28 15.94     ~ 1 0
82 [HWS2003] X51 X 07 45 09 -37 51.5   15.57 14.84     ~ 1 0
83 [HWS2003] X17 X 07 45 09 -37 41.5   15.26 14.29     ~ 1 0
84 CPD-37 1556 V* 07 45 09.5982453816 -38 00 04.302132696   12.01 11.45     ~ 9 0
85 [HWS2003] X125 X 07 45 10 -38 04.1   15.78 15.08     ~ 1 0
86 [HWS2003] X87 X 07 45 10 -37 57.2   20.64 19.08     ~ 1 0
87 [HWS2003] X20 X 07 45 10 -37 42.1   19.17 18.09     ~ 1 0
88 [HWS2003] X29 X 07 45 12 -37 45.2   14.05 13.30     ~ 1 0
89 [HWS2003] X28 X 07 45 12 -37 44.6   14.22 13.58     ~ 1 0
90 [HWS2003] X37 X 07 45 13 -37 47.5   19.64 17.99     ~ 1 0
91 CD-37 3862A * 07 45 14.9371224264 -38 11 46.469175540 10.882 10.905 10.424 10.155 9.874 ~ 15 0
92 * c Pup * 07 45 15.2961339331 -37 58 06.906935781 7.06 5.34 3.61 2.26 1.26 K4III 98 0
93 NGC 2451 126 * 07 45 15.6 -37 54 40   12.82 12.10     ~ 4 0
94 [HWS2003] X89 X 07 45 19 -37 57.4   19.66 18.31     ~ 1 0
95 2MASS J07452051-3753587 * 07 45 20.5201690200 -37 53 58.757303508   15.011 13.945 13.342 12.809 ~ 11 0
96 CPD-37 1565 * 07 45 20.9516593224 -37 49 52.921957368 12.353 12.406 11.840 11.511 11.169 ~ 12 0
97 [HWS2003] X152 X 07 45 22 -38 09.8   14.19 13.21     ~ 1 0
98 2MASS J07452245-3804103 * 07 45 22.4623948248 -38 04 10.419240180   21.15 19.271 17.979 16.426 ~ 6 0
99 [HWS2003] X185 X 07 45 23 -38 30.6   19.15 17.93     ~ 1 0
100 NGC 2451 Cl* 07 45.4 -37 58           ~ 158 1
101 [HWS2003] X78 X 07 45 24 -37 55.7   17.29 16.29     ~ 1 0
102 CD-37 3869 * 07 45 26.5269615168 -38 11 47.280396696 12.030 11.997 11.438 11.137 10.816 ~ 8 0
103 Cl* NGC 2451 AR 119 * 07 45 26.7900134592 -37 48 29.917926360   13.62 13.05     ~ 2 0
104 [HWS2003] X113 X 07 45 27 -38 00.9   20.52 18.91     ~ 1 0
105 HD 63079 * 07 45 27.3624173688 -37 35 46.630622868   6.857 6.909     B9V 52 0
106 2MASS J07452886-3805532 * 07 45 28.8724051464 -38 05 53.258510076   18.74 18.904 17.558 16.015 ~ 5 0
107 Cl* NGC 2451 AR 122 * 07 45 28.8936823296 -37 51 23.293070352   14.31 13.51     ~ 8 0
108 [HWS2003] X95 X 07 45 32 -37 58.4   20.03 18.96     ~ 1 0
109 2MASS J07453282-3751230 * 07 45 32.8242233448 -37 51 23.077985076 20.094 19.315 17.737 16.477 14.919 ~ 6 0
110 [HWS2003] X7 X 07 45 34 -37 30.5   13.43 12.73     ~ 1 0
111 2MASS J07453450-3751529 * 07 45 34.5049548216 -37 51 52.974311472 14.490 14.222 13.383 12.921 12.463 ~ 14 0
112 [HWS2003] X39 X 07 45 35 -37 48.0   13.03 12.45     ~ 1 0
113 2MASS J07453561-3755001 * 07 45 35.6106336960 -37 55 00.197947200   18.50 17.080 15.976 14.829 ~ 4 0
114 [HWS2003] X163 X 07 45 37 -38 13.5   15.15 14.35     ~ 1 0
115 CD-37 3870 * 07 45 38.5491327864 -37 46 41.755495548   12.153 11.513     ~ 19 0
116 [HWS2003] X24 X 07 45 39 -37 44.4   18.24 17.37     ~ 1 0
117 CD-37 3871 * 07 45 42.1922892864 -37 44 38.148009000   11.74 11.23     ~ 8 0
118 Cl* NGC 2451 AR 134 * 07 45 45.8525800056 -37 53 49.976603736   14.167 13.360 12.872 12.314 ~ 10 0
119 [HWS2003] X150 X 07 45 46 -38 09.2   14.43 13.50     ~ 1 0
120 2MASS J07454698-3756220 * 07 45 46.9817047680 -37 56 22.081166808   20.39 18.874 17.368 15.594 ~ 8 0
121 [HWS2003] X187 X 07 45 50 -38 33.9   13.42 12.58     ~ 2 0
122 [HWS2003] X159 X 07 45 53 -38 12.5   12.62 11.94     ~ 1 0
123 [HWS2003] X56 X 07 45 54 -37 51.8   17.90 16.51     ~ 1 0
124 [HWS2003] X127 X 07 45 56 -38 04.1   18.28 16.95     ~ 1 0
125 [HWS2003] X96 X 07 45 59 -37 58.6   14.43 13.54     ~ 1 0
126 CPD-37 1582 * 07 46 01.8650535768 -38 00 27.076765500 12.613 12.723 12.041 11.696 11.384 ~ 9 0
127 [HWS2003] X91 X 07 46 02 -37 57.8   19.01 17.47     ~ 1 0
128 2MASS J07460224-3804461 Y*? 07 46 02.2482623400 -38 04 46.240262688   20.780 18.979 15.439 15.813 ~ 4 0
129 2MASS J07460836-3753517 * 07 46 08.3628413568 -37 53 51.805505868   17.475 15.952 14.920 13.666 ~ 14 0
130 [HWS2003] X3 X 07 46 09 -37 24.8   11.18 10.66     ~ 2 0
131 HD 63216 * 07 46 10.2175479504 -38 06 05.654948652   8.53 8.61     B9V 21 0
132 HD 63215 Be* 07 46 10.5442184088 -37 56 01.239555912   5.755 5.869     B5V 62 0
133 [HWS2003] X47 X 07 46 11 -37 50.4   14.95 14.18     ~ 1 0
134 CD-37 3885 * 07 46 11.4570450456 -37 31 50.619807804   11.94 11.45     ~ 10 0
135 2MASS J07461185-3812360 * 07 46 11.8530760368 -38 12 36.022641840 14.470 14.198 13.407 12.938 12.508 ~ 8 0
136 CD-38 3636 * 07 46 14.2322026824 -38 27 57.749867208   12.12 11.53     ~ 2 0
137 [HWS2003] X162 X 07 46 20 -38 12.9   21.89 21.46     ~ 1 0
138 Cl* NGC 2451 PKB 2361 * 07 46 24.8481216792 -38 01 10.602695496 14.299 13.646 12.703 10.098 11.770 ~ 19 0
139 [HWS2003] X141 X 07 46 25 -38 06.5   20.23 19.29     ~ 1 0
140 [HWS2003] X108 X 07 46 25 -38 00.1   15.94 14.57     ~ 2 0
141 2MASS J07462980-3752442 * 07 46 29.8025349312 -37 52 44.337936108   19.176 17.618 16.359 14.725 ~ 14 0
142 CD-37 3897 * 07 46 35.5472134440 -38 06 43.843303980   10.33 10.01     ~ 10 0
143 CD-37 3901 SB* 07 46 48.4085499192 -38 08 53.718727236   9.890 9.453 9.191 8.953 ~ 14 0
144 [HWS2003] X22 X 07 46 54 -37 43.1   18.24 16.72     ~ 1 0
145 [HWS2003] X178 X 07 46 55 -38 22.7   17.37 15.77     ~ 1 0
146 [HWS2003] X160 X 07 47 04 -38 12.5   17.88 16.32     ~ 1 0
147 [HWS2003] X90 X 07 47 07 -37 57.7   16.91 15.97     ~ 1 0
148 HD 63465 Pu* 07 47 24.9925592232 -38 30 40.110462576 4.32 4.952 5.068     B2IV/V 70 0
149 CD-38 3650B * 07 47 25.9206175800 -38 30 38.883430296   11.37 10.90     ~ 6 0
150 CD-37 3910 * 07 47 25.9396121328 -37 48 15.527894472   11.85 11.37     ~ 10 0
151 Cl* NGC 2451 PKB 2381 * 07 47 44.1735094008 -37 59 03.154073496   12.585 11.860     ~ 15 0
152 [HWS2003] X117 X 07 48 07 -38 02.2   13.40 12.54     ~ 2 0
153 [HWS2003] X120 X 07 48 14 -38 02.9   13.24 12.62     ~ 1 0
154 Cl* NGC 2451 PKB 1611 ** 07 48 18.55752 -38 22 38.8128           ~ 6 0

To bookmark this query, right click on this link: simbad:objects in 2003A&A...402..571H and select 'bookmark this link' or equivalent in the popup menu