NGC 1395 is an

elliptical galaxy An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are one of the four main classes of galaxy described by Edwin Hubble in his Hubble sequence and 1936 work ''The R ...

located in the constellation Eridanus. It is located at a distance of circa 75 million

light year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from Earth, which, given its apparent dimensions, means that NGC 1395 is about 130,000 light years across. It was discovered by

William Herschel Frederick William Herschel (; german: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline H ...

on November 17, 1784. It is a member of the

Eridanus Cluster The Eridanus Cluster is a galaxy cluster roughly from Earth, containing about 73 main Galaxy, galaxies and about 200 total galaxies. About 30% have Hubble sequence, Hubble classifications of elliptical or S0 and the remaining 70% are spiral o ...

Characteristics

In the centre of NGC 1395 lies a

supermassive black hole A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical obj ...

whose mass is estimated to be (10^8.59) based on the

M–sigma relation The M–sigma (or ''M''–''σ'') relation is an empirical correlation between the stellar velocity dispersion ''σ'' of a galaxy bulge and the mass M of the supermassive black hole at its center. The ''M''–''σ'' relation was first presented i ...

or between 100 and 257 million (10⁸ – 10^8.41) based on the Sérsic index of the galaxy. NGC 1395 emits

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

s which have been observed by

Chandra X-ray Observatory The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources 1 ...

and

XMM-Newton ''XMM-Newton'', also known as the High Throughput X-ray Spectroscopy Mission and the X-ray Multi-Mirror Mission, is an X-ray space observatory launched by the European Space Agency in December 1999 on an Ariane 5 rocket. It is the second cornerst ...

. The luminosity of the galaxy in X-rays is ergs and is believed it is emitted by hot gas with total mass . One other source of X-ray emission in early type galaxies are X-ray binary stars, with 24 sources being detected in the inner area of NGC 1395. NGC 1395 is home to a large number of

globular cluster A globular cluster is a spheroidal conglomeration of stars. Globular clusters are bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many millions of membe ...

s, with their total number estimated to be , compared to 150–200 in and around the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...

. There are two different populations of globular clusters in the galaxy, named blue and red from their photometric color. The clusters of the red subpopulation lie closer to the centre of the galaxy while the blue ones lie mostly in the halo. The surface density profile of the blue globular clusters indicates that the galaxy has accreted a significant number of dwarf satellites.

David Malin David Frederick Malin (born 28 March 1941) is a British-Australian astronomer and photographer. He is principally known for his spectacular colour images of astronomical objects. A galaxy is named after him, Malin 1, which he discovered in ...

and Dave Carter discovered in 1983 low contrast shells in the bright envelope of NGC 1395. The brightest shell lies 3 arcminutes northwest of the galactic centre. A perpendicular feature is seen also in deep imaging in the northwest part of the galaxy. Features like these are indicative of recent

accretion Accretion may refer to: Science * Accretion (astrophysics), the formation of planets and other bodies by collection of material through gravity * Accretion (meteorology), the process by which water vapor in clouds forms water droplets around nucl ...

of a smaller galaxy in the recent past.

Nearby galaxies

NGC 1395 is part of the

and is the brightest member of the NGC 1395 subgroup. Other members of this subgroup are the galaxies IC 1952, NGC 1401, NGC 1414, NGC 1415, NGC 1422, NGC 1426, NGC 1438, and NGC 1439.

References

External links

NGC 1395 on SIMBAD
{{DEFAULTSORT:NGC 1395 Eridanus Group Elliptical galaxies Shell galaxies Eridanus (constellation)

1395 Year 1395 ( MCCCXCV) was a common year starting on Friday (link will display full calendar) of the Julian calendar, the 1395th year of the Common Era (CE) and ''Anno Domini'' (AD) designations, the 395th year of the 2nd millennium, the 95th year ...

13419 Discoveries by William Herschel Astronomical objects discovered in 1784