NGC 4293

NGC 4293 is a lenticular galaxy in the northern constellation of Coma Berenices. It was discovered by English astronomer William Herschel on March 14, 1784, who described it as "large, extended, resolvable, 6 or 7′ long". This galaxy is positioned to the north-northwest of the star 11 Comae Berenices and is a member of the Virgo Cluster of galaxies.^[5] It is assumed to lie at the same distance as the Virgo Cluster itself: around 54 million light years away.^[4] The galaxy spans an apparent area of 5.3 × 3.1 arc minutes.^[5]

NGC 4293
Partial image of NGC 4293 taken by the Hubble Space Telescope
Observation data (J2000 epoch)
Constellation	Coma Berenices
Right ascension	12h 21m 12.891s[1]
Declination	+18° 22′ 56.64″[1]
Redshift	0.002977[2]
Heliocentric radial velocity	893[3]
Distance	54 Mly (16.5 Mpc)[4]
Group or cluster	Virgo Cluster
Apparent magnitude (V)	10.4[5]
Characteristics
Type	(R)SB(s)0/a[6]
Apparent size (V)	5.293′ × 1.800′[1]
Other designations
2MASX J12211289+1822566, IRAS 12186+1839, LEDA 39907, UGC 7405, UZC J122112.6+182256, Z 99-23, VCC 460.[7]

The morphological classification of NGC 4293 is (R)SB(s)0/a, with the SB0/a indicating this has just distinguishable tightly wound spiral arms with a bar structure at the nucleus. An '(s)' notation means that this galaxy does not have a ring-like structure around the nucleus.^[6][8] Star formation within NGC 4293 is only taking place within a confined region at the center of the galaxy.^[9] The outer stellar disk of the galaxy appears disturbed, suggesting some form of gravitational interaction.^[10]

This is a common type of active galaxy known as a LINER, which means that the optical spectrum is dominated by emission lines from gases in low energy ionization states. The activity may be the result of a supermassive black hole (SMBH) in the nucleus that is undergoing a low rate of matter accretion. The estimated mass of such an SMBH is 5.9×10⁷ M_⊙.^[11] Radio emission from thermal activity has been detected from the proximity of this object.^[12]

Gallery

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  NGC 4293 (SDSS DR14)
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  NGC 4293 by Hubble Space Telescope