NGC 7742

Last updated
NGC 7742 [1]
Seyfert Galaxy NGC 7742.jpg
A Hubble Space Telescope (HST) image of NGC 7742.
Credit: NASA/ESA/STScI/AURA.
Observation data (J2000 epoch)
Constellation Pegasus
Right ascension 23h 44m 15.7s [2]
Declination +10° 46 02 [2]
Redshift 0.005547±0.000003 [2]
Helio radial velocity 1663±1 km/s [2]
Galactocentric velocity1809±6 km/s [2]
Distance 72.4 ± 6.2  Mly (22.20 ± 1.90  Mpc)
Apparent magnitude  (V)12.35 [2]
Characteristics
Type SA(r)b, [2] LINER/HII [2]
Apparent size  (V)1.778 × 1.698 moa [3]
Other designations
UGC 12760, [2] MCG +02-60-010, [2] UZC J234415.8+104601, [2] 2MASX J23441571+1046015 [2]

NGC 7742 also known as Fried Egg Galaxy is a face-on unbarred spiral galaxy in the constellation Pegasus. It is also classified as a Type II Seyfert Galaxy.

Contents

The galaxy is unusual in that it contains a ring but no bar. [4] Typically, bars are needed to produce a ring structure. The bars' gravitational forces move gas to the ends of the bars, where it forms into the rings seen in many barred spiral galaxies. In this galaxy, however, no bar is present, so this mechanism cannot be used to explain the formation of the ring. O. K. Sil'chenko and A. V. Moiseev proposed that the ring was formed partly as the result of a merger event in which a smaller gas-rich dwarf galaxy collided with NGC 7742. As evidence for this, they point to the unusually bright central region, the presence of highly inclined central gas disk, and the presence of gas that is counterrotating (or rotating in the opposite direction) with respect to the stars. [4]

Two Type II supernovae, SN 1993R and SN 2014cy, have been detected in NGC 7742. [5]

See also

Related Research Articles

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<span class="mw-page-title-main">NGC 7331</span> Unbarred spiral galaxy in the constellation Pegasus

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<span class="mw-page-title-main">NGC 3169</span> Galaxy in the constellation Sextans

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<span class="mw-page-title-main">NGC 2775</span> Galaxy in the constellation Cancer

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<span class="mw-page-title-main">NGC 4036</span> Lenticular galaxy in the constellation Ursa Major

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<span class="mw-page-title-main">NGC 1084</span> Galaxy in the constellation Eridanus

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<span class="mw-page-title-main">NGC 4699</span> Spiral galaxy in the constellation Virgo

NGC 4699 is an intermediate spiral galaxy located in the constellation Virgo. It is located at a distance of circa 65 million light years from Earth, which, given its apparent dimensions, means that NGC 4699 is about 85,000 light years across. It was discovered by William Herschel in 1786. It is a member of the NGC 4699 Group of galaxies, which is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster.

<span class="mw-page-title-main">NGC 6753</span> Galaxy in the constellation Pavo

NGC 6753 is a massive unbarred spiral galaxy, seen almost exactly face-on, in the southern constellation of Pavo. It was discovered by the English astronomer John Herschel on July 5, 1836. The galaxy is located at a distance of 142 million light years from the Milky Way, and is receding with a heliocentric radial velocity of 3,140 km/s. It does not display any indications of a recent interaction with another galaxy or cluster.

<span class="mw-page-title-main">NGC 3631</span> Galaxy in the constellation Ursa Major

NGC 3631 is a spiral galaxy located in the constellation Ursa Major. It is located at a distance of about 35 million light years from Earth, which, given its apparent dimensions, means that NGC 3631 is about 60,000 light years across. It was discovered by William Herschel on April 14, 1789. It is a grand design spiral galaxy seen face on.

<span class="mw-page-title-main">NGC 615</span> Unbarred spiral galaxy in the constellation Cetus

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<span class="mw-page-title-main">NGC 7469</span> Galaxy located in the constellation Pegasus

NGC 7469 is an intermediate spiral galaxy in the constellation of Pegasus. NGC 7469 is located about 200 million light-years away from Earth, which means, given its apparent dimensions, that NGC 7469 is approximately 90,000 light-years across. It was discovered by William Herschel on November 12, 1784.

<span class="mw-page-title-main">NGC 3367</span> Spiral galaxy in the constellation Leo

NGC 3367 is a barred spiral galaxy located in the constellation Leo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 3367 is about 85,000 light years across. It was discovered by William Herschel on March 19, 1784.

<span class="mw-page-title-main">NGC 5965</span> Spiral galaxy in the constellation Draco

NGC 5965 is a spiral galaxy located in the constellation Draco. It is located at a distance of circa 150 million light years from Earth, which, given its apparent dimensions, means that NGC 5965 is about 260,000 light years across. It was discovered by William Herschel on May 5, 1788.

<span class="mw-page-title-main">NGC 759</span> Galaxy in the constellation Andromeda

NGC 759 is an elliptical galaxy located 230 million light-years away in the constellation Andromeda. NGC 759 was discovered by astronomer by Heinrich d'Arrest on September 17, 1865. It is a member of Abell 262.

<span class="mw-page-title-main">NGC 4324</span> Lenticular galaxy in the constellation of Virgo

NGC 4324 is a lenticular galaxy located about 85 million light-years away in the constellation Virgo. It was discovered by astronomer Heinrich d'Arrest on March 4, 1862. NGC 4324 has a stellar mass of 5.62 × 1010M, and a baryonic mass of 5.88 × 1010M. The galaxy's total mass is around 5.25 × 1011M. NGC 4324 is notable for having a ring of star formation surrounding its nucleus. It was considered a member of the Virgo II Groups until 1999, when its distance was recalculated and it was placed in the Virgo W Group.

References

  1. Filho, M. E.; Barthel, P. D.; Ho, L. C. (October 2002). "The Nature of Composite LINER/HII Galaxies, Part II". The Astrophysical Journal Supplement. 142 (2): 223–238. arXiv: astro-ph/0205196 . Bibcode:2002ApJS..142..223F. doi:10.1086/341786. ISSN   0067-0049. S2CID   16100301.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 "NASA/IPAC Extragalactic Database". Results for NGC 7742. Retrieved 2006-08-20.
  3. "Centre de Données astronomiques de Strasbourg". Results for NGC 7742. Retrieved 2008-07-09.
  4. 1 2 O. K. Sil'chenko; A. V. Moiseev (2006). "Nature of Nuclear Rings in Unbarred Galaxies: NGC 7742 and NGC 7217". Astronomical Journal. 131 (3): 1336–1346. arXiv: astro-ph/0512431 . Bibcode:2006AJ....131.1336S. doi:10.1086/499945. S2CID   14589261.
  5. "List of Supernovae". IAU Central Bureau for Astronomical Telegrams . Retrieved 13 September 2015.