Sh 2-279

Last updated • 3 min readFrom Wikipedia, The Free Encyclopedia
Sh-279
Nebula
NGC1977 Running Man Nebula from the Mount Lemmon SkyCenter Schulman Telescope courtesy Adam Block.jpg
Sh-279 as taken from the Mount Lemmon Observatory [1]
Observation data: J2000.0 epoch
Right ascension 05h 35m 16.2s [2]
Declination −04° 47′ 07″ [2]
Distance1,500  ly
Apparent magnitude (V)7.0
Apparent dimensions (V)40′×25′ (1977) arcmins
Constellation Orion
Physical characteristics
Radius ~7.5 ly (1977), 2 ly (1975)
1 ly (1973) ly
DesignationsSh-279, NGC 1977-73-75
See also: Lists of nebulae

Sh 2-279 (alternatively designated S279 or Sharpless 279) is an HII region and bright nebulae that includes a reflection nebula located in the constellation Orion. It is the northernmost part of the asterism known as Orion's Sword, lying 0.6° north of the Orion Nebula. The reflection nebula embedded in Sh 2-279 is popularly known as the Running Man Nebula. [1] [3]

Contents

Sh 2-279 [2] comprises three NGC nebulae, NGC 1973, NGC 1975, and NGC 1977 [4] that are divided by darker nebulous regions. It also includes the open cluster NGC 1981. The brightest nebulosity, later listed as NGC 1977, was discovered by William Herschel in 1786. He catalogued it as "H V 30" and described "!! 42 Orionis and neb[ula]". The two smaller reflection nebulae were first noted by German astronomer Heinrich Louis d'Arrest, NGC 1973 in 1862 and NGC 1975 in 1864. [5] All three were included in the New General Catalogue in 1888. [6] The designation NGC 1977 is used in various sources for the reflection area around 42 Orionis (the south-east portion of the reflection nebula), for the entire reflection nebula (including NGC 1973 and NGC 1975), or for the whole nebula complex. [5]

This whole region in Orion's Sword was also later catalogued as Orion 1c. In 1966, van den Bergh distinguished the weak clustering of reflection nebulae that includes Sh 2-279 as Ori R2. [7] Every reflection nebula appearing within the Sharpless catalogue was first identified on blue plates of the Palomar Sky Survey, and then double checked against the red plates to eliminate possible plate faults. Van den Berg found that there was a strong concentration of new T Tauri stars around the Orion Nebula, tapering off into a tail approaching Sh 2-279. [7]

The Running Man Nebula is a popular target for amateur astrophotographers, as it lies close to the Orion Nebula and has many nearby guide stars. The outline of the running man shows up primarily in photographs; it is difficult to perceive visually through telescopes, though the reflection nebula itself is visible in small to medium apertures in dark skies.

Ionization Source

The whole reflection nebula region is likely excited by the hot young star (YSO) called c Orionis, 42 Orionis or HD 37018 [8] in NGC 1977, [9] which appears as a 4.6 magnitude star some 3.8′ from the centre of Sh 2-279. (See image box.) Other massive stars include the yellow giant 45 Orionis and the variable KX Orionis. [10]

Proplyds in NGC 1977

One candidate proplyd was discovered in NGC 1977 with the Hubble Space Telescope in 2012. The object showed a bent protostellar jet and a possible ionization front facing 42 Orionis, suggesting it is a proplyd. [11] In 2016 a group of astronomers discovered six proplyds with the Hubble Space Telescope and one proplyd with the Spitzer Space Telescope. The proplyds are pointing to the B-star 42 Orionis, which is the main source of ultraviolet radiation in this region. This ultraviolet light is photoevaporating the proto-planetary disks and the stellar wind of 42 Orionis is shaping the gas into cometary tails. Proplyds were first discovered in large numbers in the Orion Nebula, but there the ultraviolet source responsible for the photoevaporation is the O-type star Theta1 Orionis C. 42 Orionis is the first instance of a B-type star being responsible for the photoevaporation. [9]

All proplyds in NGC 1977 lie within 0.3 parsec of 42 Orionis and two have resolved central sources in the Hubble images, which might be the disks with radii of about 70 and 48 astronomical units. [9]

NGC 1977 also includes the young star Parengo 2042 (P 2042). [12]

Related Research Articles

<span class="mw-page-title-main">Nebula</span> Body of interstellar clouds

A nebula is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral, or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regions, such as in the Pillars of Creation in the Eagle Nebula. In these regions, the formations of gas, dust, and other materials "clump" together to form denser regions, which attract further matter and eventually become dense enough to form stars. The remaining material is then thought to form planets and other planetary system objects.

<span class="mw-page-title-main">Planetary nebula</span> Type of emission nebula created by dying red giants

A planetary nebula is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.

<span class="mw-page-title-main">Emission nebula</span> Nebula formed of ionized gases that emit light of various wavelengths

An emission nebula is a nebula formed of ionized gases that emit light of various wavelengths. The most common source of ionization is high-energy ultraviolet photons emitted from a nearby hot star. Among the several different types of emission nebulae are H II regions, in which star formation is taking place and young, massive stars are the source of the ionizing photons; and planetary nebulae, in which a dying star has thrown off its outer layers, with the exposed hot core then ionizing them.

<span class="mw-page-title-main">Orion Nebula</span> Diffuse nebula in the constellation Orion

The Orion Nebula is a diffuse nebula situated in the Milky Way, being south of Orion's Belt in the constellation of Orion,[b] and is known as the middle "star" in the "sword" of Orion. It is one of the brightest nebulae and is visible to the naked eye in the night sky with an apparent magnitude of 4.0. It is 1,344 ± 20 light-years (412.1 ± 6.1 pc) away and is the closest region of massive star formation to Earth. The M42 nebula is estimated to be 24 light-years across. It has a mass of about 2,000 times that of the Sun. Older texts frequently refer to the Orion Nebula as the Great Nebula in Orion or the Great Orion Nebula.

<span class="mw-page-title-main">H II region</span> Large, low-density interstellar cloud of partially ionized gas

An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds of light years, and density from a few to about a million particles per cubic centimetre. The Orion Nebula, now known to be an H II region, was observed in 1610 by Nicolas-Claude Fabri de Peiresc by telescope, the first such object discovered.

<span class="mw-page-title-main">Proplyd</span> Dust ring surrounding large stars thousands of solar radii wide

A proplyd, short for ionized protoplanetary disk, is an externally illuminated photoevaporating protoplanetary disk around a young star. Nearly 180 proplyds have been discovered in the Orion Nebula. Images of proplyds in other star-forming regions are rare, while Orion is the only region with a large known sample due to its relative proximity to Earth.

<span class="mw-page-title-main">Tarantula Nebula</span> H II region in the constellation Dorado

The Tarantula Nebula is a large H II region in the Large Magellanic Cloud (LMC), forming its south-east corner.

<span class="mw-page-title-main">North America Nebula</span> Emission nebula in the constellation Cygnus

The North America Nebula is an emission nebula in the constellation Cygnus, close to Deneb. It is named because its shape resembles North America.

Photoevaporation is the process where energetic radiation ionises gas and causes it to disperse away from the ionising source. The term is typically used in an astrophysical context where ultraviolet radiation from hot stars acts on clouds of material such as molecular clouds, protoplanetary disks, or planetary atmospheres.

<span class="mw-page-title-main">Horsehead Nebula</span> Dark nebula in Orions Belt

The Horsehead Nebula is a small dark nebula in the constellation Orion. The nebula is located just to the south of Alnitak, the easternmost star of Orion's Belt, and is part of the much larger Orion molecular cloud complex. It appears within the southern region of the dense dust cloud known as Lynds 1630, along the edge of the much larger, active star-forming H II region called IC 434.

<span class="mw-page-title-main">Lagoon Nebula</span> Emission nebula in Sagittarius

The Lagoon Nebula is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and has an H II region.

<span class="mw-page-title-main">NGC 7027</span> Planetary nebula in the constellation Cygnus

NGC 7027, also known as the Jewel Bug Nebula or the Magic Carpet Nebula, is a very young and dense planetary nebula located around 3,000 light-years from Earth in the constellation Cygnus. Discovered in 1878 by Édouard Stephan using the 800 mm (31 in) reflector at Marseille Observatory, it is one of the smallest planetary nebulae and by far the most extensively studied.

<span class="mw-page-title-main">Orion molecular cloud complex</span> Star-forming region in the constellation Orion

The Orion molecular cloud complex is a star-forming region with stellar ages ranging up to 12 Myr. Two giant molecular clouds are a part of it, Orion A and Orion B. The stars currently forming within the complex are located within these clouds. A number of other somewhat older stars no longer associated with the molecular gas are also part of the complex, most notably the Orion's Belt, as well as the dispersed population north of it. Near the head of Orion there is also a population of young stars that is centered on Meissa. The complex is between 1 000 and 1 400 light-years away, and hundreds of light-years across.

<span class="mw-page-title-main">NGC 2023</span> Emission nebula in the constellation Orion

NGC 2023 is an emission and reflection nebula in the equatorial constellation of Orion. It was discovered by the German-born astronomer William Herschel on 6 January 1785. This reflection nebula is one of the largest in the sky, with a size of 10 × 10 arcminutes. It is located at a distance of 1,300 ly (400 pc) from the Sun, and is positioned ~15′ to the northeast of the Horsehead Nebula.

<span class="mw-page-title-main">NGC 602</span> Open cluster in the constrellation Hydrus

NGC 602 is a young, bright open cluster of stars located in the Small Magellanic Cloud (SMC), a satellite galaxy to the Milky Way. It was discovered on 1 August 1826 by Scottish astronomer James Dunlop. It is embedded in a nebula known as N90.

<span class="mw-page-title-main">NGC 2261</span> Reflection nebula in the constellation Monoceros

NGC 2261 is a variable nebula located in the constellation Monoceros. The nebula is illuminated by the star R Monocerotis, which is not directly visible itself.

<span class="mw-page-title-main">Sh 2-185</span>

Sh 2-185 is an H II region centered on the massive star system Gamma Cassiopeiae in the northern constellation of Cassiopeia. It was included in the second Catalogue of H II Regions, published in 1959 by Stewart Sharpless. Sh 2-185 is located at a distance of approximately 10,500 ly (3.23 kpc) from the Sun. The region is surrounded by a dust shell, and displays several infrared point sources that are a characteristics of young stellar objects.

<span class="mw-page-title-main">Proplyd 114-426</span> Proplyd 114-426 is a protoplanetary disk

Proplyd 114-426 is a large protoplanetary disk seen in absorption in front of the emission of the Orion Nebula. It is one of the largest protoplanetary disks in the Orion Nebula with a diameter of 950 AU.

References

  1. 1 2 Normandin, George P. "NGC 1977, NGC 1975, and NGC 1973, Running Man Nebula". www.kopernik.org. Retrieved 5 March 2017.
  2. 1 2 3 "SH 2-279". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 12 March 2017.
  3. ↑ "'Running Man' Races in Spectacular Nebula Photo". Space.com. 12 June 2013. Retrieved 5 March 2017.
  4. ↑ "APOD: 2007 December 20 - Reflections on the 1970s". apod.nasa.gov. Retrieved 5 March 2017.
  5. 1 2 Peterson, D.E.; Megeath, S.T. (2008). The Orion Molecular Cloud 2/3 and NGC 1977 Regions : Handbook of Star Forming Regions, Volume I: The Northern Sky ASP Monograph Publications, Vol. 4. Edited by Bo Reipurth. ASP. pp. 590–618. arXiv: 0809.4006 . Bibcode:2008hsf1.book..590P.
  6. ↑ Dreyer, J. L. E. (1888). A New General Catalogue of Nebulae and Clusters of Stars, being the Catalogue of the late Sir John F.W. Herschel. Memoirs of the Royal Astronomical Society, Vol. 49, p.1. Bibcode: 1888MmRAS..49....1D . hdl: 2027/uc2.ark:/13960/t6b27rj62 . OCLC   1049897326.[ page needed ]
  7. 1 2 van den Bergh, S. (1966). "A study of reflection nebulae". Astrophysical Journal. 71: 990–998. Bibcode:1966AJ.....71..990V. doi:10.1086/109995.
  8. ↑ "* c Ori". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 12 March 2017.
  9. 1 2 3 Kim, Jinyoung Serena; Clarke, Cathie J.; Fang, Min; Facchini, Stefano (20 July 2016). "Proplyds Around a B1 Star: 42 Orionis in NGC 1977". The Astrophysical Journal Letters. 826 (1): L15. arXiv: 1606.08271 . Bibcode:2016ApJ...826L..15K. doi: 10.3847/2041-8205/826/1/L15 .
  10. ↑ Johnson, H. M.; Snow, T. P., Jr.; Gehrz, R. D.; Hackwell, J. A. (April 1977). "Copernicus spectra and infrared photometry of 42 Orionis". Publications of the Astronomical Society of the Pacific. 89: 165. Bibcode:1977PASP...89..165J. doi: 10.1086/130096 .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  11. ↑ Bally, John; Youngblood, Allison; Ginsburg, Adam (10 September 2012). "The Spindle: An Irradiated Disk and Bent Protostellar Jet in Orion". The Astrophysical Journal. 756 (2): 137. Bibcode:2012ApJ...756..137B. doi: 10.1088/0004-637X/756/2/137 .
  12. ↑ Gianopoulos, Andrea (2021-11-19). "Hubble Spots a Swift Stellar Jet in Running Man Nebula". NASA. Retrieved 2022-09-27.


This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.