Messier 100

Messier 100
Type	SA(s)bc
Epoch	J2000
Appmag v	10.2
Size v	7.4′ × 6.3′
Constellation name	Coma Berenices
Names	NGC 4321, UGC 7450, PGC 40140

Messier 100

Messier 100 is a grand-design spiral galaxy in Coma Berenices noted for its pronounced spiral structure and active star-forming regions. It has been the subject of studies by facilities such as the Hubble Space Telescope, the Very Large Array, and the European Southern Observatory and appears in catalogs compiled by Charles Messier and later surveys like the New General Catalogue. The galaxy’s morphology and nuclear activity connect it to broader topics including spiral galaxy structure, galactic dynamics, and starburst phenomena.

Description and Location

Messier 100 lies in the sky within the boundaries of Coma Berenices and was cataloged during the era of Charles Messier and contemporaries such as William Herschel and John Herschel. It is also listed in the New General Catalogue as NGC 4321 and appears in the Uppsala General Catalogue of Galaxies and the Principal Galaxies Catalogue. The galaxy’s position has made it a target for surveys by instruments on missions like the Hubble Space Telescope, the Spitzer Space Telescope, and ground-based observatories including Keck Observatory and the Very Large Telescope. Historically it was observed in programs associated with the Royal Astronomical Society and later featured in investigations by teams from institutions such as the Max Planck Institute for Astronomy and the Smithsonian Astrophysical Observatory.

Physical Characteristics

The galaxy is classified as a grand-design spiral galaxy of type SA(s)bc in morphological schemes developed by Edwin Hubble and refined by researchers following the Hubble sequence. Its optical extent is several arcminutes across, with an apparent magnitude near 10.2, comparable in brightness to other Virgo cluster members like M87 and M49. Studies using instruments from NASA and the European Space Agency have examined its stellar populations, interstellar medium, and rotation curve, comparing results with models from flat rotation curve studies and dark matter halo profiles attributed to researchers influenced by Vera Rubin and Ken Freeman. Kinematic mapping with arrays such as the Very Large Array and interferometers like the Atacama Large Millimeter/submillimeter Array has helped trace its gas dynamics and spiral density wave patterns linked to theories by C.C. Lin and Frank Shu.

Star Formation and Nucleus

Messier 100 hosts prominent H II regions and circumnuclear star-forming rings that drew attention in observations by teams including those at the Space Telescope Science Institute and the European Southern Observatory. Ultraviolet imaging by the GALEX mission and optical spectroscopy from facilities like Keck Observatory and Gemini Observatory have revealed young massive star clusters and ongoing starburst activity analogous to regions studied in M51 and NGC 4736. The nucleus exhibits low-level activity sometimes classified alongside low-ionization nuclear emission-line regions investigated in studies involving Seyfert galaxies and works by astronomers such as Alain S. Wilson and Baldwin, Phillips & Terlevich (BPT) diagnostic schemes. Infrared observations by the Spitzer Space Telescope and submillimeter data from JCMT provide constraints on dust content and molecular gas reservoirs compared with results in surveys conducted by the Herschel Space Observatory.

Supernovae and Variable Objects

Several supernovae have been recorded in this galaxy, discovered by observers and surveys including amateur networks affiliated with the International Astronomical Union and professional projects like the Palomar Transient Factory and the Sloan Digital Sky Survey. These transient events have been cross-referenced with studies in stellar evolution by researchers influenced by Subrahmanyan Chandrasekhar and Stan Woosley, and their light curves have been modeled using frameworks developed at institutions such as Caltech and Harvard-Smithsonian Center for Astrophysics. Variable stars and compact remnants in the system have been targets for follow-up using telescopes at Mount Wilson Observatory and instruments associated with the European Space Agency and NASA.

Observational History

The object was recorded during the late 18th and early 19th centuries in the catalogs of Charles Messier, and later received detailed study by observers including William Parsons, 3rd Earl of Rosse with the Leviathan of Parsonstown and subsequent photographic and spectroscopic follow-up by teams at the Lick Observatory and Palomar Observatory. Modern high-resolution imaging by the Hubble Space Telescope advanced understanding of its stellar clusters and dust lanes, while multiwavelength campaigns involving Chandra X-ray Observatory, Spitzer Space Telescope, and radio facilities contributed to a comprehensive view akin to multi-observatory programs led by consortia from institutions like the Max Planck Society and National Radio Astronomy Observatory.

Distance and Membership in the Virgo Cluster

Distance estimates for the galaxy have been derived using methods including the Tully–Fisher relation, Cepheid variable measurements pioneered by Henrietta Leavitt and refined by teams including researchers at the Carnegie Institution for Science, and surface brightness fluctuation techniques employed by groups associated with the Hubble Key Project. These distance measurements place it within the Virgo Cluster, a prominent component of the Local Supercluster (also known as the Virgo Supercluster) studied since the work of Harlow Shapley and Martin Schwarzschild. Its membership in the cluster links it to environmental processes such as tidal interactions and ram-pressure effects investigated in comparative analyses involving cluster members like M100 peers, whose dynamics are modeled in simulations conducted by researchers at institutions including the Institute for Computational Cosmology and Princeton University.

Category:Spiral galaxies