NGC 4945

NGC 4945
NGC 4945 image take by the MPG/ESO 2.2-metre telescope at La Silla Observatory
Observation data (J2000 epoch)
Constellation	Centaurus
Right ascension	13^h 05^m 27.5^s[1]
Declination	−49° 28′ 06″[1]
Redshift	563 ± 3 km/s[1]
Distance	11.7 Mly (3.6 Mpc)[2]
Apparent magnitude (V)	9.3[1]
Characteristics
Type	SB(s)cd[1]
Apparent size (V)	20.0′ × 3.8′[1]
Other designations
PGC 45279,[1] Caldwell 83

The location of NGC 4945 (labelled in red)

NGC 4945 (also known as Caldwell 83) is a barred spiral galaxy in the constellation Centaurus, visible near the star Xi Centauri.^[3] The galaxy was discovered by James Dunlop in 1826 and is thought to be similar to the Milky Way Galaxy, although X-ray observations show that NGC 4945 has an unusual energetic Seyfert 2 nucleus that might house a supermassive black hole.^[4] Around the nucleus of the galaxy, there is a dense disk of dust and gas, along with many dense star clusters.^[5] This object has an estimated mass of 1.4+1.4
−0.7×10¹¹ M_☉.^[6]

Supernovae

Two supernovae have been observed in NGC 4945:

• SN 2005af (Type II, mag. 12.8) was discovered by CEAMIG/REA Supernovae Search on 8 February 2005.^[7][8]
• SN 2011ja (type IIP, mag. 14) was discovered by Libert "Berto" Monard on 18 December 2011.^[9][10]

Galaxy group

NGC 4945 one of the brightest galaxies of the Centaurus A/M83 Group, a large, nearby group of galaxies. The galaxy is the second brightest galaxy in the subgroup centered on Centaurus A.^[2][11]

In popular culture

"NGC 4945" is the title of a song by Brett Domino on the album Funk.

References

1. "NASA/IPAC Extragalactic Database". Results for NGC 4945. Retrieved 2006-11-25.
2. I. D. Karachentsev; M. E. Sharina; A. E. Dolphin; E. K. Grebel; et al. (2002). "New distances to galaxies in the Centaurus A group". Astronomy and Astrophysics. 385 (1): 21–31. Bibcode:2002A&A...385...21K. doi:10.1051/0004-6361:20020042.
3. http://www.docdb.net/show_object.php?id=ngc_4945, NGC 4945 : DOCdb :Deep Sky Observer's Companion – the online database
4. "Milky Way's Not-So-Distant Cousin Likely Harbors Supermassive Black Hole". Science Daily.
5. Gaspar, G.; Díaz, R. J.; Mast, D.; Agüero, M. P.; Schirmer, M.; Günthardt, G.; Schmidt, E. O. (2022). "An Infrared View of the Obscured AGN Environment in NGC 4945". The Astronomical Journal. 163 (5): 230. arXiv:2203.03678. Bibcode:2022AJ....163..230G. doi:10.3847/1538-3881/ac5ea4. S2CID 247315251.
6. Graham, Alister W. (November 2008), "Populating the Galaxy Velocity Dispersion - Supermassive Black Hole Mass Diagram: A Catalogue of (Mbh, σ) Values", Publications of the Astronomical Society of Australia, 25 (4): 167–175, arXiv:0807.2549, Bibcode:2008PASA...25..167G, doi:10.1071/AS08013, S2CID 89905.
7. Jacques, C.; Pimentel, E. (2005). "Possible Supernova in NGC 4945". International Astronomical Union Circular (8482): 1. Bibcode:2005IAUC.8482....1J.
8. "SN 2005af". Transient Name Server. IAU. Retrieved 8 December 2024.
9. Monard, L. A. G.; Milisavljevic, D.; Fesen, R.; Pickering, T.; Romero-Colmenero, E.; Turatto, M.; Benetti, S.; Pastorello, A.; Valenti, S.; Bufano, F.; Tomasella, L.; Ryder, S.; Soderberg, A.; Stockdale, C.; Van Dyk, S.; Immler, S.; Weiler, K.; Panagia, N. (2011). "Supernova 2011ja in NGC 4945 = PSN J13051112-4931270". Central Bureau Electronic Telegrams. 2946: 1. Bibcode:2011CBET.2946....1M.
10. "SN 2011ja". Transient Name Server. IAU. Retrieved 8 December 2024.
11. I. D. Karachentsev (2005). "The Local Group and Other Neighboring Galaxy Groups". Astronomical Journal. 129 (1): 178–188. arXiv:astro-ph/0410065. Bibcode:2005AJ....129..178K. doi:10.1086/426368. S2CID 119385141.

External links

• NGC 4945 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
• APOD: Nearby Spiral Galaxy NGC 4945 (7/21/02)
• ESO: The milkyway's nearby cousin (2/10/09)