NGC 6902
NGC 6902 taken by SPECULOOS [1] [2]
Observation data ( J2000 epoch)
Constellation	Sagittarius
Right ascension	20h 24m 28.067s [3]
Declination	−43° 39′ 12.42″ [3]
Redshift	0.009300±0.000023 [4]
Heliocentric radial velocity	2793.9 km/s [5]
Distance	124  Mly (38.0  Mpc) [6]
Apparent magnitude (V)	10.93±0.18 [6]
Apparent magnitude (B)	11.64±0.18 [6]
Characteristics
Type	SA(r)b [6]
Apparent size (V)	3.55 ′ × 2.69 ′ [7]
Other designations
Gaia DR2 6678974930431764096, IRAS 20210-4348, F20210-4348, 2MASX J20242813-4339127, NGC 6902, LEDA 64632, MCG -07-42-002 [8]

NGC 6902 is an unbarred spiral galaxy located in the southern constellation of Sagittarius at an approximate distance of 124 million light-years (38.0  Mpc). ^[6] NGC 6902 was discovered on September 2, 1836 by English astronomer John Herschel. ^[9] In his New General Catalogue, Danish astronomer J. L. E. Dreyer described it as faint, considerably small, round, brighter middle. ^{[10] [11]} It is a member of the small NGC 6092 group of galaxies; the LGG 434 group ^[9]

The morphological classification of NGC 6902 is SA(r)b, ^[6] indicating an unbarred spiral galaxy (SA) with an inner ring (r) and somewhat tightly wound arms (b). As the two arms extend outward, they transition into a complex system of filamentary arms. The galaxy has an angular size of 3.55 ′ × 2.69 ′ in the optical band. ^[7] The galactic plane is inclined at an angle of 38±5° to the line of sight from the Earth. NGC 6902 has a high abundance of neutral hydrogen; about three times greater than a typical galaxy of this class. ^[12] The ring structure is undergoing extensive star formation. Although classed as unbarred, there is a small bar of stars inside the ring. ^[9]

Gallery

• 
  NGC 6902 by GALEX
• 
  Center of NGC 6902 by Very Large Telescope

References

External links

• "Results for object NGC 6902 (NGC 6902)". NASA/IPAC Extragalactic Database. California Institute of Technology. Retrieved 2020-12-12.
• Media related to NGC 6902 at Wikimedia Commons