Messier 100

Messier 100
Galaxy Messier 100 by ESO revealing complex spiral arm structure
Observation data (J2000 epoch)
Constellation	Coma Berenices [1]
Right ascension	12h 22m 54.9s [2]
Declination	+15° 49′ 21″ [2]
Redshift	1571 ± 1 km/s [2]
Distance	55 Mly [3]
Group or cluster	Virgo Cluster
Apparent magnitude  (V)	9.3 [4]
Characteristics
Type	SAB(s)bc [2]
Size	107,000 ly (diameter)
Apparent size  (V)	7′.4 × 6′.3 [2]
Other designations
NGC 4321

Messier 100 (also known as NGC 4321) is a grand design intermediate spiral galaxy in the southern part of the mildly northern Coma Berenices. ^[5] It is one of the brightest and largest galaxies in the Virgo Cluster and is approximately 55 million light-years ^[3] from our galaxy, its diameter being 107,000 light years, and being about 60% as large. It was discovered by Pierre Méchain in 1781 ^{[lower-alpha 1]} and 29 days later seen again and entered by Charles Messier in his catalogue "of nebulae and star clusters". ^{[6] [7]} It was one of the first spiral galaxies to be discovered, ^[7] and was listed as one of fourteen spiral nebulae by Lord William Parsons of Rosse in 1850. NGC 4323 and NGC 4328 are satellite galaxies of M100; the former is connected with it by a bridge of luminous matter. ^{[8] [9]}

Early observations

After the discovery of M100 by Méchain, Charles Messier made observations of the galaxy depicting it as a nebula without a star. He pointed out that it was difficult ^[7] to recognize the nebula because of its faintness. William Herschel was able to identify a bright cluster of stars ^[7] within the "nebula" during his observations. His son John expanded the findings in 1833. With the advent of better telescopes, John Herschel was able to see a round, brighter galaxy; however, he also mentioned that it was barely visible through clouds. William Henry Smyth ^[7] extended the studies of M100, detailing it as a pearly white nebula and pointing out diffuse spots.

Star formation

Messier 100 is considered a starburst galaxy ^[10] with the strongest star formation activity concentrated in its center, within a ring – actually two tightly wound spiral arms attached to a small nuclear bar of radius: one thousand parsecs ^[11] – where star formation has been taking place for at least 500 million years in separate bursts. ^[12]

As usual on spiral galaxies of the Virgo Cluster, in the rest of the disk both star formation ^[13] and neutral hydrogen, of which M100 is deficient compared to isolated spiral galaxies of similar Hubble type, ^[14] are truncated within the galaxy's disk, which is caused by interactions with the intracluster medium of Virgo.

Supernovae

Seven supernovae have been identified in M100. ^[5]

• In March 1901 the first was found, SN 1901B, ^{[5] [15]} a type I supernova found with a magnitude of 15.6 at 110"W and 4"N from its nucleus.
• SN 1914A ^{[5] [16]} was then discovered in February to March 1914; its type was undeterminable but was found with a magnitude of 15.7 at 24"E and 111"S from its nucleus.
• Galactic observation from early to mid 1960 ^{[lower-alpha 2]} found SN 1959E, another type I supernova, ^{[5] [17]} with the faintest magnitude, 17.5, among the five found, at 58"E and 21"S from its nucleus.
• On April 15, 1979, the first type II supernova found in the M100 galaxy was discovered; however the star SN 1979C ^{[5] [18]} faded quickly; later observations from x-ray to radio wavelengths revealed its remnant.
• The fifth supernova was discovered February 7, 2006; the star SN 2006X ^{[5] [19]} had a magnitude of 15.3 when discovered two weeks before fading to magnitude +17.
• Supernova SN 2019ehk, discovered on April 29, 2019, reached a peak magnitude of approximately 15.8.
• The seventh supernova, SN 2020oi, was discovered on January 7, 2020. It was a type Ic supernova, which reached a peak magnitude of 17.7. ^{[5] [20]}

Gallery

• 
  Image of Messier 100 taken by the NASA/ESA Hubble Space Telescope
• 
  Messier 100 Hubble images centered on supernova SN 2019ehk

See also

• List of Messier objects

References and footnotes

1. R. W. Sinnott, ed. (1988). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer. Sky Publishing Corporation/Cambridge University Press. ISBN   978-0-933346-51-2.
2. "NASA/IPAC Extragalactic Database". Results for NGC 4321. Retrieved 2006-08-31.
3. "Messier 100". Hearst Observatory . Retrieved 2010-02-23.
4. "Messier 100". SEDS Messier Catalog. Retrieved 30 April 2022.
5. "Messier 100". SEDS: Spiral Galaxy M100 (NGC 4321), type Sc, in Coma Berenices. Retrieved 2010-02-23.
6. "Catalog of Nebulae and Star Clusters". SEDS . Retrieved 2010-02-23.
7. "Messier 100". SEDS: Observations and Descriptions. Retrieved 2010-02-23.
8. S. di Serego Alighieri; et al. (2007). "The HI content of Early-Type Galaxies from the ALFALFA survey I. Catalogued HI sources in the Virgo cluster". Astronomy and Astrophysics . 474 (3): 851–855. arXiv: 0709.2096 . Bibcode:2007A&A...474..851D. doi:10.1051/0004-6361:20078205. S2CID   5332365.
9. "NGC 4323". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2010-02-23.
10. Wozniak, H.; Friedli, D.; Martinet, L.; Pfenniger, D. (1999). "Double-barred starburst galaxies viewed by ISOCAM". The Universe as Seen by ISO. 427: 989. Bibcode:1999ESASP.427..989W.
11. Sakamoto, Kazushi; Okumura, Sachiko; Minezaki, Takeo; Kobayashi, Yukiyasu; et al. (1995). "Bar-Driven Gas Structure and Star Formation in the Center of M100". The Astronomical Journal. 110 (3): 2075. Bibcode:1995AJ....110.2075S. doi:10.1086/117670.
12. Allard, E. L.; Knapen, J. H.; Peletier, R. F.; Sarzi, M. (2006). "The star formation history and evolution of the circumnuclear region of M100". Monthly Notices of the Royal Astronomical Society . 371 (3): 1087–1105. arXiv: astro-ph/0606490 . Bibcode:2006MNRAS.371.1087A. doi:10.1111/j.1365-2966.2006.10751.x. S2CID   119370091.
13. R. A. Koopmann; J. D. P. Kenney (2004). "Hα Morphologies and Environmental Effects in Virgo Cluster Spiral Galaxies". Astrophysical Journal . 613 (2): 866–885. arXiv: astro-ph/0406243 . Bibcode:2004ApJ...613..866K. doi:10.1086/423191. S2CID   17519217.
14. Chung, A.; Van Gorkom, J.H.; Kenney, J.F.P.; Crowl, Hugh; et al. (2009). "VLA Imaging of Virgo Spirals in Atomic Gas (VIVA). I. The Atlas and the H I Properties". The Astronomical Journal. 138 (6): 1741–1816. Bibcode:2009AJ....138.1741C. doi: 10.1088/0004-6256/138/6/1741 .
15. "SN 1901B". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2010-02-23.
16. "SN 1914A". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2010-02-23.
17. "SN 1959E". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2010-02-23.
18. "SN 1979C". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2010-02-23.
19. "SN 2006X". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2010-02-23.
20. "SN 2020oi". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2010-02-23.

1. On March 15
2. February 21 to June 17

External links

• SEDS: Spiral Galaxy 100
• Messier 100 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
• ESA/Hubble Messier 100
• NASA Astronomy Picture of the Day