IC 1613

IC 1613 (object 1613 in the Index Catalogues (IC), also known as Caldwell 51) is an irregular dwarf galaxy, visible in the constellation Cetus near the star 26 Ceti.^[6] It was discovered in 1906 by Max Wolf,^[7] and is approaching Earth at 234 km/s.

IC 1613
IC 1613 captured with the VLT's OmegaCAM.[1]
Observation data (J2000 epoch)
Constellation	Cetus
Right ascension	01h 04m 47.8s[2]
Declination	+02° 07′ 04″[2]
Redshift	−234±1 km/s[2]
Distance	2.38±0.07 Mly (730±20 kpc)[3][4]
Group or cluster	Local Group
Apparent magnitude (V)	9.9[2]
Absolute magnitude (V)	−15.2[5]
Characteristics
Type	IB(s)m[2]
Mass	(1.1±0.2)×108[5] M☉
Apparent size (V)	16.2′ × 14.5′[2]
Other designations
UGC 668,[2] DDO 8,[2] PGC 3844,[2] Caldwell 51

The sky around IC 1613, with 26 Ceti towards the bottom of the frame (south) and 29 Ceti to the left (east)

IC 1613 is a member of the Local Group.^[8] It has played an important role in the calibration of the Cepheid variable period-luminosity relation for estimating distances.^[9] Other than the Magellanic Clouds, it is one of the few Local Group dwarf irregular galaxy where RR Lyrae-type variables have been observed; this factor, along with an unusually low abundance of interstellar dust both within IC 1613 and along the line of sight enable especially accurate distance estimates.^[8][10]

In 1999, Cole et al.^[8] used the Hubble Space Telescope to find that the dominant population of this galaxy has an age of ~7 Gyr. Using its Hess diagram, they found that its evolutionary history may be similar to that of the Pegasus Dwarf Irregular Galaxy. Both galaxies are classified as Ir V in the DDO system. Also in 1999, Antonello et al. found five cepheids of Population II in IC 1613, giving self-evident support for the existence of a very old stellar population component of IC 1613. In 1999, King, Modjaz, & Li discovered the first nova ever detected in IC 1613.^[11]

Hubble image of the central part of IC 1613, showing the faint galaxies of a background galaxy cluster.

IC 1613 contains a WO star known as DR1, which might be the only Wolf–Rayet star in the galaxy,^[12][13] although a candidate WC+O binary, SPIRITS14bqe, has been found.^[14] A Luminous Blue Variable candidate,^[15] has been proposed but a revised classification led to a B2.5 III type.^[16] Moreover, a rich population of OB-type^[16] stars and OB associations^[17] has been discovered.

There are many faint galaxies close to IC 1613, 14 of which are catalogued as members of a yet-unnamed galaxy cluster located at z≈0.20.^[18]

References

1. "The Milky Way's Clean and Tidy Galactic Neighbour". Retrieved 29 January 2016.
2. "NASA/IPAC Extragalactic Database". Results for IC 1613. Retrieved 2006-11-29.
3. I. D. Karachentsev; V. E. Karachentseva; W. K. Hutchmeier; D. I. Makarov (2004). "A Catalog of Neighboring Galaxies". Astronomical Journal. 127 (4): 2031–2068. Bibcode:2004AJ....127.2031K. doi:10.1086/382905.
4. Karachentsev, I. D.; Kashibadze, O. G. (2006). "Masses of the local group and of the M81 group estimated from distortions in the local velocity field". Astrophysics. 49 (1): 3–18. Bibcode:2006Ap.....49....3K. doi:10.1007/s10511-006-0002-6. S2CID 120973010.
5. Skillman, Evan D.; Hidalgo, Sebastian L.; Weisz, Daniel R.; Monelli, Matteo; Gallart, Carme; Aparicio, Antonio; Bernard, Edouard J.; Boylan-Kolchin, Michael; Cassisi, Santi; Cole, Andrew A.; Dolphin, Andrew E.; Ferguson, Henry C.; Mayer, Lucio; Navarro, Julio F.; Stetson, Peter B.; Tolstoy, Eline (15 April 2014). "The ACS LCID project. X. The star formation history of IC 1613: revisiting the over-cooling problem". The Astrophysical Journal. 786 (1): 44. arXiv:1403.4609. Bibcode:2014ApJ...786...44S. doi:10.1088/0004-637X/786/1/44.
6. Cole, Andrew A.; Tolstoy, Eline; Gallagher III, John S.; Hoessel, John G.; Mould, Jeremy R.; Holtzman, Jon A.; Saha, Abhijit; Ballester, Gilda E.; Burrows, Christopher J.; Clarke, John T.; Crisp, David (October 1999). "Stellar Populations at the Center of IC 1613". The Astronomical Journal. 118 (4): 1657–1670. arXiv:astro-ph/9905350. Bibcode:1999AJ....118.1657C. doi:10.1086/301042. hdl:11370/f890fe5e-7780-4296-b2e0-a1e6e4b51f11. S2CID 17566586.
7. Cole, Andrew A.; Tolstoy, Eline; Gallagher III, John S.; Hoessel, John G.; Mould, Jeremy R.; Holtzman, Jon A.; Saha, Abhijit; Ballester, Gilda E.; Burrows, Christopher J.; Clarke, John T.; Crisp, David (October 1999). "Stellar Populations at the Center of IC 1613". The Astronomical Journal. 118 (4): 1657–1670. arXiv:astro-ph/9905350. Bibcode:1999AJ....118.1657C. doi:10.1086/301042. hdl:11370/f890fe5e-7780-4296-b2e0-a1e6e4b51f11. S2CID 17566586.
8. Cole, Andrew A.; Tolstoy, Eline; Gallagher, John S., III; Hoessel, John G.; Mould, Jeremy R.; Holtzman, Jon A.; Saha, Abhijit; Ballester, Gilda E.; Burrows, Christopher J.; Clarke, John T.; Crisp, David; Griffiths, Richard E.; Grillmair, Carl J.; Hester, Jeff J.; Krist, John E.; Meadows, Vikki; Scowen, Paul A.; Stapelfeldt, Karl R.; Trauger, John T.; Watson, Alan M.; Westphal, James R. (1999). "Stellar Populations at the Center of IC 1613". The Astronomical Journal. 118 (4): 1657–1670. arXiv:astro-ph/9905350. Bibcode:1999AJ....118.1657C. doi:10.1086/301042. S2CID 17566586.{{cite journal}}: CS1 maint: multiple names: authors list (link)
9. Cole, Andrew A.; Tolstoy, Eline; Gallagher III, John S.; Hoessel, John G.; Mould, Jeremy R.; Holtzman, Jon A.; Saha, Abhijit; Ballester, Gilda E.; Burrows, Christopher J.; Clarke, John T.; Crisp, David (October 1999). "Stellar Populations at the Center of IC 1613". The Astronomical Journal. 118 (4): 1657–1670. arXiv:astro-ph/9905350. Bibcode:1999AJ....118.1657C. doi:10.1086/301042. hdl:11370/f890fe5e-7780-4296-b2e0-a1e6e4b51f11.
10. "The Milky Way's Clean and Tidy Galactic Neighbour".
11. van den Bergh, Sidney (April 2000). "Updated Information on the Local Group". The Publications of the Astronomical Society of the Pacific. 112 (770): 529–536. arXiv:astro-ph/0001040. Bibcode:2000PASP..112..529V. doi:10.1086/316548. S2CID 1805423.
12. Neugent, Kathryn; Massey, Philip (2019-08-01). "The Wolf–Rayet Content of the Galaxies of the Local Group and Beyond". Galaxies. 7 (3): 74. arXiv:1908.06238. Bibcode:2019Galax...7...74N. doi:10.3390/galaxies7030074.
13. Tramper, F.; Straal, S. M.; Sanyal, D.; Sana, H.; De Koter, A.; Gräfener, G.; Langer, N.; Vink, J. S.; De Mink, S. E.; Kaper, L. (2015). "Massive stars on the verge of exploding: The properties of oxygen sequence Wolf–Rayet stars". Astronomy & Astrophysics. 581: A110. arXiv:1507.00839. Bibcode:2015A&A...581A.110T. doi:10.1051/0004-6361/201425390. S2CID 56093231.
14. Lau, Ryan M.; Hankins, Matthew J.; Kasliwal, Mansi M.; Bond, Howard E.; De, Kishalay; Jencson, Jacob E.; Moffat, Anthony F. J.; Smith, Nathan; Williams, Peredur M. (2021-03-01). "Revealing Efficient Dust Formation at Low Metallicity in Extragalactic Carbon-rich Wolf–Rayet Binaries". The Astrophysical Journal. 909 (2): 113. arXiv:2011.09732. Bibcode:2021ApJ...909..113L. doi:10.3847/1538-4357/abd8cd. ISSN 0004-637X. S2CID 227053768.
15. Herrero, A.; Garcia, M.; Uytterhoeven, K.; Najarro, F.; Lennon, D. J.; Vink, J. S.; Castro, N. (2010). "The nature of V39: an LBV candidate or LBV impostor in the very low metallicity galaxy IC 1613?". Astronomy and Astrophysics. 513: A70. arXiv:1003.0875. Bibcode:2010A&A...513A..70H. doi:10.1051/0004-6361/200913562. ISSN 0004-6361. S2CID 54068837.
16. Garcia, M.; Herrero, A. (2013). "The young stellar population of IC 1613". Astronomy & Astrophysics. 551: A74. arXiv:1211.4582. Bibcode:2013A&A...551A..74G. doi:10.1051/0004-6361/201219977. ISSN 0004-6361. S2CID 56300058.
17. Garcia, M.; Herrero, A.; Castro, N.; Corral, L.; Rosenberg, A. (2012). "The young stellar population of IC 1613". Astronomy & Astrophysics. 523: A23. arXiv:1211.4582. Bibcode:2010A&A...523A..23G. doi:10.1051/0004-6361/201015243. ISSN 0004-6361. S2CID 120326367.
18. Karl Krienke; Paul W. Hodge (2001). "Hubble Space Telescope Photometry of Clusters of Galaxies behind the Dwarf Irregular Galaxies DDO 216 and IC 1613 and the Small Magellanic Cloud". Publications of the Astronomical Society of the Pacific. 113 (787): 1115–1121. Bibcode:2001PASP..113.1115K. doi:10.1086/322838.

External links

• Media related to IC 1613 at Wikimedia Commons
• IC 1613 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images