IC 5146
Reflection nebula | |
---|---|
emission nebula | |
Optical image of IC 5146 | |
Observation data: J2000 epoch | |
Right ascension | 21h 53m 28.7s |
Declination | +47° 16′ 01″ |
Distance | 2500±100[1] ly (780±30 pc) |
Apparent magnitude (V) | +7.2 |
Apparent dimensions (V) | 12′ |
Constellation | Cygnus |
Physical characteristics | |
Radius | 7.5 ly |
Designations | Cocoon Nebula, Caldwell 19, Sh 2-125, Cr 470 |
See also: Lists of nebulae |
IC 5146 (also Caldwell 19, Sh 2-125, Barnard 168, and the Cocoon Nebula) is a reflection[2]/emission[3] nebula and Caldwell object in the constellation Cygnus. The NGC description refers to IC 5146 as a cluster of 9.5 mag stars involved in a bright and dark nebula. The cluster is also known as Collinder 470.[4] It shines at magnitude +10.0[5]/+9.3[3]/+7.2.[6] Its celestial coordinates are RA 21h 53.5m , dec +47° 16′. It is located near the naked-eye star Pi Cygni, the open cluster NGC 7209 in Lacerta, and the bright open cluster M39.[2][5] The cluster is about 4,000 ly away, and the central star that lights it formed about 100,000 years ago;[7] the nebula is about 12 arcmins across, which is equivalent to a span of 15 light years.[6]
When viewing IC 5146, dark nebula Barnard 168 (B168) is an inseparable part of the experience, forming a dark lane that surrounds the cluster and projects westward forming the appearance of a trail behind the Cocoon.
Young Stellar Objects
IC 5146 is a stellar nursery where star-formation is ongoing. Observations by both the Spitzer Space Telescope and the Chandra X-ray Observatory have collectively identified hundreds of young stellar objects.[8][9] Young stars are seen in both the emission nebula, where gas has been ionized by massive young stars, and in the infrared-dark molecular cloud that forms the "tail". One of the most massive stars in the region is BD +46 3474, a star of class B1 that is an estimated 14±4 times the mass of the sun.[10]
Another interesting star in the nebula is BD +46 3471, which is an example of a HAeBe star, an intermediate mass star with strong emission lines in its spectrum.[11]
References
- ^ Kuhn, Michael A.; Hillenbrand, Lynne A.; Sills, Alison; Feigelson, Eric D.; Getman, Konstantin V. (2018). "Kinematics in Young Star Clusters and Associations with Gaia DR2". The Astrophysical Journal. 870 (1): 32. arXiv:1807.02115. Bibcode:2019ApJ...870...32K. doi:10.3847/1538-4357/aaef8c. S2CID 119328315.
- ^ a b Eicher, David J. (1988). The Universe from Your Backyard: A Guide to Deep-Sky Objects from Astronomy Magazine. AstroMedia (Kalmbach Publishing Company). ISBN 0-521-36299-7.
- ^ a b Sanqunetti, Doug (2007). "IC 5146 - Cocoon Nebula". dougsastro.net. Retrieved 2008-08-06.[permanent dead link]
- ^ O'Meara, Stephen James: The Caldwell Objects, Sky Publishing Corporation ISBN 0-933346-97-2 page 80
- ^ a b Pasachoff, Jay M. (2000). "Atlas of the Sky". Stars and Planets. New York, NY: Peterson Field Guides. p. 578. ISBN 0-395-93432-X.
- ^ a b Cannistra, Steve (2004). "Cocoon Nebula". starrywonders.com. Retrieved 2008-08-06.
- ^ Nemiroff, R.; Bonnell, J., eds. (2002-10-14). "IC 5146: The Cocoon Nebula". Astronomy Picture of the Day. NASA. Retrieved 2008-08-06.
- ^ Harvey, Paul M.; Huard, Tracy L.; Jørgensen, Jes K.; Gutermuth, Robert A.; Mamajek, Eric E.; Bourke, Tyler L.; Merín, Bruno; Cieza, Lucas; Brooke, Tim; Chapman, Nicholas; Alcalá, Juan M.; Allen, Lori E.; Evans II, Neal J.; Di Francesco, James; Kirk, Jason M. (2008). "TheSpitzerSurvey of Interstellar Clouds in the Gould Belt. I. IC 5146 Observed With IRAC and MIPS". The Astrophysical Journal. 680 (1): 495–516. Bibcode:2008ApJ...680..495H. doi:10.1086/587687. ISSN 0004-637X.
- ^ Getman, Konstantin V.; Broos, Patrick S.; Kuhn, Michael A.; Feigelson, Eric D.; Richert, Alexander J. W.; Ota, Yosuke; Bate, Matthew R.; Garmire, Gordon P. (2017). "Star Formation In Nearby Clouds (SFiNCs): X-Ray and Infrared Source Catalogs and Membership". The Astrophysical Journal Supplement Series. 229 (2): 28. arXiv:1612.05282. Bibcode:2017ApJS..229...28G. doi:10.3847/1538-4365/229/2/28. ISSN 1538-4365. S2CID 59124520.
- ^ Weidner, Carsten; Kroupa, Pavel (2006). "The maximum stellar mass, star-cluster formation and composite stellar populations". Monthly Notices of the Royal Astronomical Society. 365 (4): 1333–1347. arXiv:astro-ph/0511331. Bibcode:2006MNRAS.365.1333W. doi:10.1111/j.1365-2966.2005.09824.x. ISSN 0035-8711. S2CID 11688023.
- ^ Reipurth, Bo (2008). Handbook of star forming regions. San Francisco: Astronomical Society of the Pacific. ISBN 978-1-58381-670-7.
External links
- "IC 5146". SIMBAD. Centre de données astronomiques de Strasbourg.
- "NED results for object IC 5146". NASA/IPAC Extragalactic Database. National Aeronautics and Space Administration / Infrared Processing and Analysis Center.
- IC 5146 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
- v
- t
- e
- Sh2-1
- Sh2-2
- Sh2-3
- Sh2-4
- Sh2-5
- Sh2-6
- Sh2-7
- Sh2-8
- Sh2-9
- Sh2-10
- Sh2-11
- Sh2-12
- Sh2-13
- Sh2-14
- Sh2-15
- Sh2-16
- Sh2-17
- Sh2-18
- Sh2-19
- Sh2-20
- Sh2-21
- Sh2-22
- Sh2-23
- Sh2-24
- Sh2-25
- Sh2-26
- Sh2-27
- Sh2-28
- Sh2-29
- Sh2-30
- Sh2-31
- Sh2-32
- Sh2-33
- Sh2-34
- Sh2-35
- Sh2-36
- Sh2-37
- Sh2-38
- Sh2-39
- Sh2-40
- Sh2-41
- Sh2-42
- Sh2-43
- Sh2-44
- Sh2-45
- Sh2-46
- Sh2-47
- Sh2-48
- Sh2-49
- Sh2-50
- Sh2-51
- Sh2-52
- Sh2-53
- Sh2-54
- Sh2-55
- Sh2-56
- Sh2-57
- Sh2-58
- Sh2-59
- Sh2-60
- Sh2-61
- Sh2-62
- Sh2-63
- Sh2-64
- Sh2-65
- Sh2-66
- Sh2-67
- Sh2-68
- Sh2-69
- Sh2-70
- Sh2-71
- Sh2-72
- Sh2-73
- Sh2-74
- Sh2-75
- Sh2-76
- Sh2-77
- Sh2-78
- Sh2-79
- Sh2-80
- Sh2-81
- Sh2-82
- Sh2-83
- Sh2-84
- Sh2-85
- Sh2-86
- Sh2-87
- Sh2-88
- Sh2-89
- Sh2-90
- Sh2-91
- Sh2-92
- Sh2-93
- Sh2-94
- Sh2-95
- Sh2-96
- Sh2-97
- Sh2-98
- Sh2-99
- Sh2-100
- Sh2-101
- Sh2-102
- Sh2-103
- Sh2-104
- Sh2-105
- Sh2-106
- Sh2-107
- Sh2-108
- Sh2-109
- Sh2-110
- Sh2-111
- Sh2-112
- Sh2-113
- Sh2-114
- Sh2-115
- Sh2-116
- Sh2-117
- Sh2-118
- Sh2-119
- Sh2-120
- Sh2-121
- Sh2-122
- Sh2-123
- Sh2-124
- Sh2-125
- Sh2-126
- Sh2-127
- Sh2-128
- Sh2-129
- Sh2-130
- Sh2-131
- Sh2-132
- Sh2-133
- Sh2-134
- Sh2-135
- Sh2-136
- Sh2-137
- Sh2-138
- Sh2-139
- Sh2-140
- Sh2-141
- Sh2-142
- Sh2-143
- Sh2-144
- Sh2-145
- Sh2-146
- Sh2-147
- Sh2-148
- Sh2-149
- Sh2-150
- Sh2-151
- Sh2-152
- Sh2-153
- Sh2-154
- Sh2-155
- Sh2-156
- Sh2-157
- Sh2-158
- Sh2-159
- Sh2-160
- Sh2-161
- Sh2-162
- Sh2-163
- Sh2-164
- Sh2-165
- Sh2-166
- Sh2-167
- Sh2-168
- Sh2-169
- Sh2-170
- Sh2-171
- Sh2-172
- Sh2-173
- Sh2-174
- Sh2-175
- Sh2-176
- Sh2-177
- Sh2-178
- Sh2-179
- Sh2-180
- Sh2-181
- Sh2-182
- Sh2-183
- Sh2-184
- Sh2-185
- Sh2-186
- Sh2-187
- Sh2-188
- Sh2-189
- Sh2-190
- Sh2-191
- Sh2-192
- Sh2-193
- Sh2-194
- Sh2-195
- Sh2-196
- Sh2-197
- Sh2-198
- Sh2-199
- Sh2-201
- Sh2-202
- Sh2-203
- Sh2-204
- Sh2-205
- Sh2-206
- Sh2-207
- Sh2-208
- Sh2-209
- Sh2-210
- Sh2-211
- Sh2-212
- Sh2-213
- Sh2-214
- Sh2-215
- Sh2-216
- Sh2-217
- Sh2-218
- Sh2-219
- Sh2-220
- Sh2-221
- Sh2-222
- Sh2-223
- Sh2-224
- Sh2-225
- Sh2-226
- Sh2-227
- Sh2-228
- Sh2-229
- Sh2-230
- Sh2-231
- Sh2-232
- Sh2-233
- Sh2-234
- Sh2-235
- Sh2-236
- Sh2-237
- Sh2-238
- Sh2-239
- Sh2-240
- Sh2-241
- Sh2-242
- Sh2-243
- Sh2-244
- Sh2-245
- Sh2-246
- Sh2-247
- Sh2-248
- Sh2-249
- Sh2-250
- Sh2-251
- Sh2-252
- Sh2-253
- Sh2-254
- Sh2-255
- Sh2-256
- Sh2-257
- Sh2-258
- Sh2-259
- Sh2-260
- Sh2-261
- Sh2-262
- Sh2-263
- Sh2-264
- Sh2-265
- Sh2-266
- Sh2-267
- Sh2-268
- Sh2-269
- Sh2-270
- Sh2-271
- Sh2-272
- Sh2-273
- Sh2-274
- Sh2-275
- Sh2-276
- Sh2-277
- Sh2-278
- Sh2-279
- Sh2-280
- Sh2-281
- Sh2-282
- Sh2-283
- Sh2-284
- Sh2-285
- Sh2-286
- Sh2-287
- Sh2-288
- Sh2-289
- Sh2-290
- Sh2-291
- Sh2-292
- Sh2-293
- Sh2-294
- Sh2-295
- Sh2-296
- Sh2-297
- Sh2-298
- Sh2-299
- Sh2-301
- Sh2-302
- Sh2-303
- Sh2-304
- Sh2-305
- Sh2-306
- Sh2-307
- Sh2-308
- Sh2-309
- Sh2-310
- Sh2-311
- Sh2-312
- Sh2-313
- See also: Gum catalog
- Nebula
- RCW Catalogue
- Stewart Sharpless