Carina Nebula

Coordinates: Sky map 10h 45m 08.5s, −59° 52′ 04″
Source: Wikipedia, the free encyclopedia.

Carina Nebula
arcmins
ConstellationCarina
Physical characteristics
Radius~230[4] ly   (~70 pc)
Notable features
  • Eta Carinae
  • Keyhole Nebula
  • Many open clusters & dark nebulae
DesignationsNGC 3372,[5] ESO 128-EN013,[1] GC 2197,[1] h 3295,[1] Caldwell 92[6]
See also: Lists of nebulae
The Cosmic Cliffs at the edge of NGC 3324, one of the first images taken by the James Webb Space Telescope

The Carina Nebula

bright and dark nebulosity in the constellation Carina, located in the Carina–Sagittarius Arm of the Milky Way galaxy. The nebula is approximately 8,500 light-years (2,600 pc) from Earth.[2]

The nebula has within its boundaries the large

Collinder 228, Collinder 232, NGC 3324, and NGC 3293
are also considered members of the association. NGC 3293 is the oldest and furthest from Trumpler 14, indicating sequential and ongoing star formation.

The nebula is one of the largest diffuse nebulae in our skies. Although it is four times as large as and even brighter than the famous Orion Nebula, the Carina Nebula is much less well known due to its location in the southern sky. It was discovered by Nicolas-Louis de Lacaille in 1752 from the Cape of Good Hope.

The Carina Nebula was selected as one of five cosmic objects observed by the James Webb Space Telescope, as part of the release of its first official science images. A detailed image was made of an early star-forming region of NGC 3324 known as the Cosmic Cliffs.[10]

Discovery and basic information

arcminutes centered on the coordinates of right ascension 10h 45m 08.5s and declination −59° 52′ 04″.[1] In modern times it is calculated to be around 8,500 light-years (2,600 pc) from Earth.[2]

Objects within the Carina Nebula

Eta Carinae

Main article: Eta Carinae
Eta Carinae observed in different wavelengths

Eta Carinae is a highly luminous hypergiant star. Estimates of its mass range from 100 to 150 times the mass of the Sun, and its luminosity is about four million times that of the Sun.

This object is currently the most massive star that can be studied in great detail, because of its location and size. Several other known stars may be

Eddington limit, i.e., the outward pressure of their radiation is almost strong enough to counteract gravity. Stars that are more than 120 solar masses exceed the theoretical Eddington limit, and their gravity is barely strong enough to hold in its radiation and gas, resulting in a possible supernova or hypernova
in the near future.

Eta Carinae's effects on the nebula can be seen directly. Dark globules and some other less visible objects have tails pointing directly away from the massive star. The entire nebula would have looked very different before the Great Eruption in the 1840s surrounded Eta Carinae with dust, drastically reducing the amount of ultraviolet light it put into the nebula.

Homunculus Nebula

Main article: Homunculus Nebula
Eta Carinae, surrounded by the Homunculus Nebula

Within the large bright nebula is a much smaller feature, immediately surrounding Eta Carinae itself, known as the Homunculus Nebula (from Latin meaning Little Man). It is believed to have been ejected in an enormous outburst in 1841 which briefly made Eta Carinae the second-brightest star in the sky.

The Homunculus Nebula is a small H II region, with gas shocked into ionized and excited states.[11] It also absorbs much of the light from the extremely luminous central stellar system and re-radiates it as infrared (IR). It is the brightest object in the sky at mid-IR wavelengths.[12]: 145–169 

The distance to the Homunculus can be derived from its observed angular dimensions and calculated linear size, assuming it is axially symmetric. The most accurate distance obtained using this method is 7,660 ± 160 light-years (2,350 ± 50 pc). The largest radius of the bipolar lobes in this model is about 22,000 AU, and the axis is oriented 41° from the line of sight, or 49° relative to the plane of the sky, which means it is seen from Earth slightly more "end on" than "side on".[13]

Keyhole Nebula

The Keyhole Nebula is a dark nebulosity superimposed on the brightest part of the Carina Nebula.

The Keyhole, or Keyhole Nebula, is a small dark cloud of cold molecules and dust within the Carina Nebula, containing bright filaments of hot, fluorescing gas, silhouetted against the much brighter background nebula.

Appleton's Journal article.[17] The name Keyhole Nebula then came into common use, sometimes for the Keyhole itself, sometimes to describe the whole of the Carina Nebula (signifying "the nebula that contains the Keyhole").[18][19]

The diameter of the Keyhole structure is approximately seven light-years (2.1 pc). Its appearance has changed significantly since it was first observed, possibly due to changes in the ionizing radiation from Eta Carinae.[20] The Keyhole does not have its own NGC designation. It is sometimes erroneously called NGC 3324,[21] but that catalogue designation refers to a reflection and emission nebula just northwest of the Carina Nebula (or to its embedded star cluster).[22][23][24]

Defiant Finger

Hubble image of the Defiant Finger. North is down.

A small Bok globule in the Keyhole Nebula (at RA 10h 44m 30s, Dec −59° 40') has been photographed by the Hubble Space Telescope and is nicknamed the "Carina Defiant Finger" due to its shape.[25] In Hubble images, light can be seen radiating off the edges of the globule; this is especially visible in the southern tip, where the "finger" is. It is thought that the Defiant Finger is being ionized by the bright Wolf–Rayet star WR 25, and/or Trumpler 16-244, a bright blue supergiant. It has a mass of at least 6 M☉, and stars may be forming within it. Like other interstellar clouds under intense radiation, the Defiant Finger will eventually be completely evaporated; for this cloud the time frame is predicted to be 200,000 to 1,000,000 years.[26]

Trumpler 14

Main article: Trumpler 14
Hubble image of the open cluster Trumpler 14

Trumpler 14 is an open cluster with a diameter of six light-years (1.8 pc), located within the inner regions of the Carina Nebula, approximately 8,000 light-years (2,500 pc) from Earth.[27] It is one of the main clusters of the Carina OB1 stellar association, which is the largest association in the Carina Nebula.[12] About 2,000 stars have been identified in Trumpler 14.[28] and the total mass of the cluster is estimated to be 4,300 M☉.[29]

Trumpler 15

Main article: Trumpler 15

Trumpler 15 is a star cluster on the north-east edge of the Carina Nebula. Early studies disagreed about the distance, but astrometric measurements by the Gaia mission have confirmed that it is the same distance as the rest of Carina OB1.[2]

Trumpler 16

Main article: Trumpler 16

Trumpler 16 is one of the main clusters of the Carina OB1 stellar association, which is the largest association in the Carina Nebula, and it is bigger and more massive than Trumpler 14.[12] The star Eta Carinae is part of this cluster.

Mystic Mountain

Main article: Mystic Mountain
Mystic Mountain

Mystic Mountain is the term for a dust–gas pillar in the Carina Nebula, a photo of which was taken by Hubble Space Telescope on its 20th anniversary. The area was observed by Hubble's Wide Field Camera 3 on 1–2 February 2010. The pillar measures three light-years (0.92 pc) in height; nascent stars inside the pillar fire off gas jets that stream from towering “peaks”.

WR 22

Main article: WR 22

WR 22 is an eclipsing binary. The dynamical masses derived from orbital fitting vary from over 70 M☉ to less than 60 M☉ for the primary and about 21 to 27 M☉ for the secondary.[30] The spectroscopic mass of the primary has been calculated at 74 M☉[31] or 78.1 M☉.[32]

WR 25

Main article: WR 25
The brightest star is WR 25

WR 25 is a binary system in the central portion of the Carina Nebula, a member of the Trumpler 16 cluster. The primary is a Wolf–Rayet star, possibly the most luminous star in the galaxy. The secondary is hard to detect but thought to be a luminous OB star.

HD 93129

Main article: HD 93129

HD 93129 is a triple star system of O-class stars in Carina. All three stars of HD 93129 are among the most luminous in the galaxy;[33] HD 93129 consists of two clearly resolved components, HD 93129 A and HD 93129 B, and HD 93129 A itself is made up of two much closer stars.

HD 93129 A has been resolved into two components. The spectrum is dominated by the brighter component, although the secondary is only 0.9 magnitudes fainter. HD 93129 Aa is an O2 supergiant and Ab is an O3.5 main sequence star.

milliarcseconds in 2004 to only 27 mas in 2013, but an accurate orbit is not available.[35]

HD 93129 B is an

arcseconds away from the closer pair. It is about 1.5 magnitudes fainter than the combined HD 93129 A, and is approximately the same brightness as HD 93129 Ab.[36][37]

HD 93250

Main article: HD 93250

HD 93250 is one of the brightest stars in the region of the Carina Nebula. It is only 7.5

arcminutes from Eta Carinae,[38] and HD 93250 is considered to be a member of the same loose open cluster Trumpler 16, although it appears closer to the more compact Trumpler 14.[39]

HD 93250 is known to be a binary star, however, individual spectra of the two components have never been observed but are thought to be very similar. The spectral type of HD 93250 has variously been given as O5,[40] O6/7,[41] O4,[42] and O3.[43] It has sometimes been classified as a main sequence star and sometimes as a giant star.[42][43] The Galactic O-Star Spectroscopic Survey has used it as the standard star for the newly created O4 subgiant spectral type.[44]

HD 93205

Main article: HD 93205

HD 93205 is a binary system of two large stars.

The more massive member of the pair is an O3.5 main sequence star. The spectrum shows some ionized nitrogen and helium emission lines, indicating some mixing of fusion products to the surface and a strong stellar wind. The mass calculated from apsidal motion of the orbits is 40 to 60 M☉. This is somewhat lower than expected from evolutionary modelling of a star with its observed parameters.[45]

The less massive member is an O8 main sequence star of approximately 20 M☉.[46] It moves in its orbit at a speed of over 300 km/s (190 mi/s) and is considered to be a relativistic binary, which causes the apses of the orbit to change in a predictable way.[47]

Catalogued open clusters in Carina Nebula

As of 1998, there are eight known open clusters in the Carina Nebula:[3]

  • Bochum 10 (Bo 10)
  • Bochum 11 (Bo 11)
  • Collinder 228 (Cr 228)[48]
  • Collinder 232 (Cr 232)
  • Collinder 234 (Cr 234)
  • Trumpler 14 (Tr 14, Cr 230)
  • Trumpler 15 (Tr 15, Cr 231)
  • Trumpler 16 (Tr 16, Cr 233)

Annotated map

Annotated map of part of the Carina Nebula showing the location of various objects in the nebula. This view combines multiple ground and Hubble observatory images in a 50-light-year wide (15 pc) view.[49]
A celestial map of the nebula.

Gallery

  • Overview of the Carina Nebula. The Keyhole is superimposed on the bright area above center, and Eta Carinae is the bright star just to its left.
    Overview of the Carina Nebula. The Keyhole is superimposed on the bright area above center, and Eta Carinae is the bright star just to its left.
  • Carina Nebula in infrared light[50]
    Carina Nebula in infrared light[50]
  • X-rays from stars and diffuse multimillion-Kelvin plasma light up the Carina Nebula in this Chandra X-ray Observatory image
    X-rays from stars and diffuse multimillion-Kelvin plasma light up the Carina Nebula in this Chandra X-ray Observatory image
  • Close-up of the Carina Nebula's central region
    Close-up of the Carina Nebula's central region
  • Wolf–Rayet star WR 22
    Wolf–Rayet star WR 22
  • Bok globule nicknamed "The Caterpillar"[51]
    Bok globule nicknamed "The Caterpillar"[51]
  • Region R44 in the Carina Nebula[52]
    Region R44 in the Carina Nebula[52]
  • Scientists taking a “deep dive” into one of the iconic first images from the James Webb Space Telescope have discovered dozens of energetic jets and outflows from young stars previously hidden by dust clouds. [53]
    Scientists taking a “deep dive” into one of the iconic first images from the James Webb Space Telescope have discovered dozens of energetic jets and outflows from young stars previously hidden by dust clouds. [53]

See also

References

  1. ^
    The NGC/IC Project. Archived from the original
    on 28 May 2009. Retrieved 29 November 2016.
  2. ^
    S2CID 119328315
    .
  3. ^ a b c Frommert, Hartmut & Kronberg, Christine (22 March 1998). "NGC 3372". SEDS.org. Archived from the original on 30 May 2016. Retrieved 26 November 2016.
  4. ^ "NGC 3372 – The Eta Carinae Nebula". Atlas of the Universe. Retrieved 1 October 2013.
  5. ^ "NGC 3372". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 3 September 2013.
  6. ISBN 978-0-521-82796-6
    .
  7. ^ "The Carina Nebula: Star Birth in the Extreme". Hubblesite. NASA. 24 April 2007. Retrieved 20 November 2020.
  8. ^ Uranometria 2000.0
  9. APOD, Picture of the day for 27 Dec 2018
  10. ^ Garner, Rob (8 July 2022). "NASA Shares List of Cosmic Targets for Webb Telescope's 1st Images". NASA. Retrieved 8 July 2022.
  11. S2CID 2460614
    .
  12. ^
    ISBN 978-1-4614-2274-7
    .
  13. S2CID 12453761
    .
  14. OCLC 5045340
    .
  15. doi:10.1098/rstl.1864.0001
    .
  16. Bibcode:1873AReg...11..221A
    .
  17. ^ Converse, Emma M. (27 December 1873). "Eta Argûs". Appletons' Journal. 10 (249): 818.
  18. doi:10.5479/ADS/bib/1914LicOB.8.55M
    .
  19. ISBN 978-0-486-23567-7
    .
  20. Bibcode:1977S&T....54...22W
    .
  21. ^ For example, see APOD – NGC 3324.
  22. ISBN 978-0-943396-89-7
    .
  23. The NGC/IC Project. Archived from the original
    on 28 May 2009. Retrieved 17 May 2014.
  24. ^ "NGC 3324". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 17 May 2014.
  25. ^ "NAME Carina Defiant Finger". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 3 April 2020.
  26. S2CID 14709621
    .
  27. S2CID 18502004
    .
  28. Bibcode:2009eso..pres...47.
    Science Release eso0947.
  29. S2CID 119294869
    .
  30. Bibcode:1999A&A...347..127S
    .
  31. S2CID 18714731
    .
  32. S2CID 16025012
    .
  33. S2CID 8258609
    .
  34. S2CID 18416034
    .
  35. S2CID 53500788
    .
  36. Bibcode:2000A&A...355L..27H
    .
  37. Bibcode:1996A&AS..116...75V
    .
  38. S2CID 119215270
    .
  39. S2CID 14060690
    .
  40. Bibcode:1973MmRAS..77..199T
    .
  41. ISBN 978-0-8357-0331-4
    .
  42. ^
    S2CID 119122481
    .
  43. ^
    doi:10.1088/0004-6256/142/5/146
    .
  44. S2CID 55658165
    .
  45. S2CID 16834579
    .
  46. S2CID 117107602
    .
  47. S2CID 16221731
    .
  48. ^ Frommert, Hartmut & Kronberg, Christine (6 May 2001). "Collinder 228". SEDS.org. Retrieved 29 November 2016.
  49. ^ "The Carina Nebula: Star Birth in the Extreme". The Hubble Heritage Project. Space Telescope Science Institute. 24 April 2007. Retrieved 14 August 2023.
  50. ^ "Stars v. Dust in the Carina Nebula". European Southern Observatory. 29 August 2018. Retrieved 30 August 2018.
  51. ^ "Carina Nebula Details: The Caterpillar". Hubblesite. Space Telescope Science Institute. 24 April 2007. Retrieved 14 August 2023.
  52. ^ "Pillars of Destruction". European Southern Observatory. 2 November 2016. Retrieved 7 December 2016.
  53. ^ "Carina Nebula Jets (NIRCam Narrowband Filters - Annotated)". 18 October 2023.

External links

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