Celestial Atlas
PGC 31000 - 31499 ←     PGC Objects: PGC 31500 - 31999 Link for sharing this page on Facebook     → PGC 32000 - 32499
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Page last updated June 28, 2017

PGC 31693
A magnitude 14.5(?) irregular galaxy (type dIm?) in
Sextans (RA 10 39 25.2, Dec +01 43 07)
Physical Information: Based on a recessional velocity of 705 km/sec (and H0 = 70 km/sec/Mpc), PGC 31693 is about 30 to 35 million light years away, in good agreement with a single redshift-independent distance estimate of 30 to 35 million light years. Given that and its apparent size of about 0.65 by 0.65 arcmin (from the images below), the galaxy is about 6 thousand light years across (hence its classification as a "dwarf" irregular), while its fainter outer regions span about 0.95 by 0.9 arcmin, or about 9 thousand light years. It is known as a starburst galaxy because it is undergoing a period of unusually intense star formation, resulting in a large number of hot bright young stars. It is also an "emission-line" galaxy, because those young stars are heating and lighting up surrounding clouds of gas and dust, causing them to fluorescence at wavelengths corresponding to their chemical composition.
SDSS image of region near irregular galaxy PGC 31693
Above, a 12 arcmin wide SDSS image centered on PGC 31693
Below, a 1.2 arcmin wide SDSS image of the galaxy
SDSS image of irregular galaxy PGC 31693
Below, a 1.2 arcmin wide HST image of the galaxy
(Image Credit ESA/Hubble & NASA; Acknowledgement Luca Limatola)
HST image of irregular galaxy PGC 31693
Celestial Atlas
PGC 31000 - 31499 ←     PGC Objects: PGC 31500 - 31999     → PGC 32000 - 32499