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Maffei 1

LBN 659

Proper NameNone
Messier NumberNone
NGC/IC NumberNone
Other DesignationsMaffei 1, LBN 659
ConstellationCassiopeia
Right Ascension2h 36m 35s
Declination+59° 39' 18"
Distancec.11,300,000 light years
c.3,500,000 parsecs
MagnitudeApparent: +11.22
Absolute: -16.47
Mean DiameterApparent: 5° 0.6'
Actual: c. 2,000 light years
Hubble TypeE-S0 elliptical / lenticular
Optimum VisibilityNovember (Usually visible from northern latitudes)

A massive lenticular or flattened elliptical galaxy in the constellation of Cassiopeia, one of the primary galaxies of the IC 342/Maffei Group, the nearest galaxy group to the Milky Way's own Local Group. Maffei 1 is estimated to lie some eleven million light years from the Milky Way, making it a relatively near neighbour in galactic terms. (Indeed, it was at one time suspected to be a member of the Local Group, but is now identified as belonging to its own independent group of galaxies).

Imagery provided by Aladin sky atlas

Maffei 1 os a large and luminous galaxy, estimated to measure some 75,000 light years across (compared to a little over 100,000 light years for the Milky Way). Being so large and so nearby on a galactic scale, the galaxy might be expected to shine prominently in the night sky of Earth. Indeed, if it lay elsewhere in the sky it would be a spectacular sight, but it falls close to the plane of the Milky Way, and its light is thus obscured by intervening material (its partner at the heart of the IC 342/Maffei Group, IC 342, is known as the 'Hidden Galaxy' for just this reason). Maffei 1 was thus not located until 1967 using infrared astronomy (its discoverer, Paolo Maffei, also identified a second galaxy in the same group using this technique, a spiral designated Maffei 2).

Maffei 1 is an elliptical galaxy with a somewhat flattened shape, and on the Hubble system it is classified both as S0 (lenticular) and E3 (elliptical). It has the 'boxy' shape of a typical massive elliptical galaxy (that is, it has a relatively undefined form that does not show a distinct disc structure), and its nucleus is tiny and inactive. It has one known major satellite galaxy, a spiral designated Dwingeloo 1, as well as several associated dwarf galaxies and numerous globular clusters.

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