Sharpless 264, also known as the Lambda Orionis Ring, is a

molecular cloud A molecular cloud, sometimes called a stellar nursery (if star formation is occurring within), is a type of interstellar cloud, the density and size of which permit absorption nebulae, the formation of molecules (most commonly molecular hydroge ...

and

H II region 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 hundre ...

, which can be seen in the northern region of the

Orion molecular cloud complex The Orion molecular cloud complex (or, simply, the Orion 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 a ...

(OMCC), in the constellation of Orion. The OMCC is one of the best-known

star formation Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as "stellar nurseries" or "star-forming regions", collapse and form stars. As a branch of astronomy, star formation includ ...

regions and the closest sector of 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 ey ...

to the

Solar System The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...

where high-mass

star A star is an astronomical object comprising a luminous spheroid of plasma held together by its gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night, but their immense distances from Earth make ...

s are born. The

nebula A nebula ('cloud' or 'fog' in Latin; pl. nebulae, nebulæ or nebulas) 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 regio ...

is named after its main star,

λ Orionis Meissa , designated Lambda Orionis (λ Orionis, abbreviated Lambda Ori, λ Ori) is a star in the constellation of Orion. It is a multiple star approximately away with a combined apparent magnitude of 3.33. The main components are a ...

, a

blue giant In astronomy, a blue giant is a hot star with a luminosity class of III (giant) or II (bright giant). In the standard Hertzsprung–Russell diagram, these stars lie above and to the right of the main sequence. The term applies to a variety of s ...

responsible for the

ionization Ionization, or Ionisation is the process by which an atom or a molecule acquires a negative or positive Electric charge, charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged a ...

of the surrounding material.Mathieu, R. D.
''The λ Orionis Star Forming Region''
''in Handbook of Star Forming Regions'', Volume I: The Northern Sky ASP Monograph Publications, vol. 4, Bo Reipurth, December 2008, p. 757, . It is also sometimes called the Angelfish Nebula due to its resemblance as to its lighter areas (pink to peach colour) to an

angelfish Angelfish may refer to: *Several groups of fish: **Freshwater angelfish, tropical cichlids of the genus ''Pterophyllum'' **Marine angelfish of the family Pomacanthidae **Atlantic pomfret (''Brama brama''), sold by fishmongers as "angelfish" in Sou ...

. In the infrared its ionized boundaries are that which appears, instead.

Observations

(also known as Meissa or Heka) at about 1,100 light-years is the

representing the head of Orion and can be found to the

north North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''no ...

of the quadrangle defined by the stars

Betelgeuse Betelgeuse is a red supergiant of spectral type M1-2 and one of the largest stars visible to the naked eye. It is usually the tenth-brightest star in the night sky and, after Rigel, the second-brightest in the constellation of Orio ...

Bellatrix Bellatrix is the third-brightest star in the constellation of Orion, positioned 5° west of the red supergiant Betelgeuse (Alpha Orionis). It has the Bayer designation γ Orionis, which is Latinized to Gamma Orionis. With a slightly ...

Rigel Rigel is a blue supergiant star in the constellation of Orion. It has the Bayer designation β Orionis, which is Latinized to Beta Orionis and abbreviated Beta Ori or β Ori. Rigel is the brightest and most massive componentand ...

and

Saiph Saiph , designation Kappa Orionis (κ Orionis, abbreviated Kappa Ori, κ Ori) and 53 Orionis (53 Ori), is the sixth-brightest star in the constellation of Orion. Of the four bright stars that compose Orion's main quadrangle, it is the st ...

. This star can be found at the centre of open cluster

Collinder 69 The Lambda Orionis Cluster (also known as the Collinder 69) is an open star cluster located north-west of the star Betelgeuse in the constellation of Orion. It is about five million years old and roughly away from the Sun. Included within the cl ...

composed of fourth and fifth-magnitude young hot stars, visible to the naked eye. It can be resolved with a pair of

binoculars Binoculars or field glasses are two refracting telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes ( binocular vision) when viewing distant objects. Most binoculars are sized to be hel ...

. The rest of the cluster and associated nebula spans a few hundred light-years centred about 1400

light-years 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 101 ...

away. The broad nebula shown is not visible unaided, with

or small amateur

telescopes A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to obser ...

. It becomes clear in long-exposure

photographs A photograph (also known as a photo, image, or picture) is an image created by light falling on a photosensitive surface, usually photographic film or an electronic image sensor, such as a CCD or a CMOS chip. Most photographs are now creat ...

, such as in the first illustration on this page.

Orange giant A giant star is a star with substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature.Giant star, entry in ''Astronomy Encyclopedia'', ed. Patrick Moore, New York: Oxford University Press, ...

φ² Orionis, while appearing to be surrounded by the Ring, is merely a foreground object at only about 116 light years from Earth.

HD 34989 HD 34989 is a blue-white star in the main sequence, of apparent magnitude 5.80, in the constellation of Orion (constellation), Orion. It is 1700 Light year, light-years from the Solar System. Observation The star is in the norther ...

is a

blue-white main sequence star In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the ...

, visible magnified only, just outside the Ring. It has a small nebulous cloud more geared towards the near-infrared than other parts of the neighbouring ionized regions across the Ring.

Gallery

Orion%27s_Big_Head_Revealed_in_Infrared.jpg, The ring shows its

status in the infrared — this image includes the very bright source of infrared and near-infrared Betelgeuse, therefore blue-white when shown converted to visible light. Sig07-006.jpg, Barnard 30, a part of the Lambda Orionis Ring seen by the

Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...

. Young stars are forming in this region. Barnard 35 Spitzer.jpg,

Barnard 35 Barnard is a version of the surname Bernard, which is a French and West Germanic masculine given name and surname. The surname means as tough as a bear, Bar(Bear)+nard/hard(hardy/tough) __NOTOC__ People Some of the people bearing the surname B ...

, a part of the Lambda Orionis Ring seen by the

. The Herbig-Haro Object

HH 175 HH may refer to: Organizations * Happy Hippie Foundation, a non-profit organization founded by Miley Cyrus * Hartmann House Preparatory School, an independent preparatory school in Harare, Zimbabwe * Heirs Holdings, a Nigerian conglomerate wit ...

is part of this structure. The bright star on the lower right part of the image is FU Orionis. HD 34989 Spitzer.jpg, The star

is surrounded by material that is part of the Lambda Orionis Ring. The images of this region were taken with the

References

External links

CCD Images of the Sharpless CatalogGalaxy Map
{{Sh2 objects Sharpless objects H II regions Orion molecular cloud complex Orion (constellation)