NGC 4889
Also Known as: Caldwell 35, NGC 4884
Object Type: Giant Elliptical Galaxy
Constellation: Coma Berenices
Distance from Earth: 308 million Light years
Apparent Magnitude: 12.9
Coordinates: RA 13H 00M 8.1S DEC 27deg 48min 37sec
Actual Size: 239,000 light years in diameter
Apparent Dimensions: 2.9 arc-minutes
Discovered by: NGC 4889 was discovered in 1785 by the British astronomer Frederick William Herschel I, who catalogued it as a bright,
nebulous patch.
NGC 4889 was not included by the astronomer Charles Messier in his famous Messier catalogue despite being an intrinsically bright object quite close to some Messier objects.
In 1888 the astronomer John Louis Emil Dreyer published the New General Catalogue of Nebulae and Clusters of Stars (NGC), with a total of 7,840 objects,
but he erroneously duplicated the galaxy in two designations, NGC 4884 and NGC 4889.
Description: NGC 4889 is the brightest galaxy within the northern Coma Cluster.
At the core of the galaxy is a supermassive black hole that heats the intracluster medium through the action of friction from infalling gases and dust.
As with other similar elliptical galaxies, only a fraction of the mass of NGC 4889 is in the form of stars.
They have a flattened, unequal distribution that bulges within its edge.
Between the stars is a dense interstellar medium full of heavy elements emitted by evolved stars.
The diffuse stellar halo extends out to one million light years in diameter.
Orbiting the galaxy is a very large population of globular clusters.
NGC 4889 lies at the center of the component A of the Coma Cluster, a giant cluster of 2,000 galaxies.
NGC 4889 is probably the largest and the most massive galaxy out to the radius of 100 Mpc (326 million light years) of the Milky Way.
In addition it has an immense diffuse light halo extending to 17.8 arcminutes, roughly half the angular diameter of the Sun, translating to 1.3 million light years in diameter.
Along with its large size, NGC 4889 may also be extremely massive. If we take the Milky Way as the standard of mass, it may be close to 8 trillion solar masses.
However, as NGC 4889 is a spheroid, and not a flat spiral, it has a three-dimensional profile, so it may be as high as 15 trillion solar masses.
Giant elliptical galaxies like NGC 4889 are believed to be the result of multiple mergers of smaller galaxies.
There is now little dust remaining to form the diffuse nebulae where new stars are created, so the stellar population is dominated by old, population II stars that contain relatively low abundances of elements other than hydrogen and helium.
The egg-like shape of this galaxy is maintained by random orbital motions of its member stars, in contrast to the more orderly rotational motions found in a spiral galaxy such as the Milky Way.
NGC 4889 has 15,800 globular clusters, more than Messier 87, which has 12,000. This is half of NGC 4874's collection of globular clusters, which has 30,000 globular clusters.
Click Below Image(s) for Full Size:
NGC 4889 is located along the high declination region of Coma Berenices, south of the constellation Canes Venatici.
With an apparent magnitude of 11.4, it can be seen by telescopes with 12 inch aperture, but its visibility is greatly affected by light pollution due to glare of the light from Beta Comae Berenices.
However, under very dark, moonless skies, it can be seen by small telescopes as a faint smudge, but larger telescopes are needed in order to see the galaxy's halo.
NGC 4889 is best observed in the autumn months.
Platesolve
NGC 4889
Imaging Details
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