Nebula | |
---|---|
Observation data: J2000.0 [1] epoch | |
Right ascension | 04h 41.0m [1] |
Declination | +25° 52′ [1] |
Constellation | Taurus |
Designations | HCL 2, Heiles's cloud 2, TMC-1, Taurus molecular cloud 1 [1] |
The Taurus molecular cloud (TMC-1) is an interstellar molecular cloud in the constellations Taurus and Auriga. This cloud hosts a stellar nursery containing hundreds of newly formed stars. [2] The Taurus molecular cloud is only 140 pc (430 ly) away from Earth, making it possibly the nearest large star formation region. It has been important in star formation studies at all wavelengths of Electromagnetic spectrum. [3]
It is notable for containing many complex molecules, such as cyanopolyynes HCnN for n = 3,5,7,9, [4] and cumulene carbenes H2Cn for n = 3–6. [5] In 2007 the polyatomic anion octatetraynyl radical was detected in TMC-1, making it the second type of anion to be found in the interstellar medium and the largest such molecule detected to date. [6] [7]
The Taurus molecular cloud was identified in the past as a part of the Gould Belt, a large structure surrounding the solar system. More recently (January 2020) the Taurus molecular cloud was identified as being part of the much larger Radcliffe wave, a wave-shaped structure in the local arm of the Milky Way.
The newly formed stars in this cloud have an age of 1–2 million years. [8] The Taurus–Auriga association, which is the stellar association of the cloud, contains the variable star T Tauri, which is the prototype of T Tauri stars. [9] The many young stars and the close proximity to Earth make it uniquely well-suited to search for protoplanetary disks and exoplanets around stars, and to identify brown dwarfs in the association. Members of this region are suited for direct imaging of young exoplanets, which glow brightly in infrared wavelengths.
Members [9] [10] of the Taurus–Auriga association with a circumstellar disk or exoplanet:
A rogue planet, also termed a free-floating planet (FFP) or an isolated planetary-mass object (iPMO), is an interstellar object of planetary mass which is not gravitationally bound to any star or brown dwarf.
XZ Tauri is a binary system approximately 460 light-years away in the constellation Taurus. The system consists of two T Tauri stars orbiting each other about 6 billion kilometers apart. The system made news in 2000 when a superflare was observed in the system.
AA Tauri is a young variable star in the equatorial constellation of Taurus, located in the Taurus-Auriga star-forming region. It is too faint to view with the naked eye, having an apparent visual magnitude that varies from 12.2 down to 16.1. The star is located approximately 439 light-years away from the Sun based on parallax, and is drifting further away with a radial velocity of +17 km/s.
2MASS J0441+2301 is a young quadruple system hosting a planetary-mass object, a red dwarf star and two brown dwarfs, approximately 470 light years away.
AB Aurigae is a young Herbig Ae star in the Auriga constellation. It is located at a distance of approximately 509 light years from the Sun based on stellar parallax. This pre-main-sequence star has a stellar classification of A0Ve, matching an A-type main-sequence star with emission lines in the spectrum. It has 2.4 times the mass of the Sun and is radiating 38 times the Sun's luminosity from its photosphere at an effective temperature of 9,772 K. The radio emission from the system suggests the presence of a thermal jet originating from the star with a velocity of 300 km s−1. This is causing an estimated mass loss of 1.7×10−8 M☉ yr−1.
Sigma Herculis, Latinized from σ Her, is a binary star system in the northern constellation of Hercules. It has a combined apparent visual magnitude of 4.18, making it bright enough to be visible to the naked eye. Based upon an annual parallax shift of 10.36 mas as seen from Earth, Sigma Herculis is located about 310 light years away from the Sun.
Scott Jay Kenyon is an American astrophysicist. His work has included advances in symbiotic and other types of interacting binary stars, the formation and evolution of stars, and the formation of planetary systems.
HL Tauri is a young T Tauri star in the constellation Taurus, approximately 450 light-years (140 pc) from Earth in the Taurus Molecular Cloud. The luminosity and effective temperature of HL Tauri imply that its age is less than 100,000 years. At apparent magnitude 15.1, it is too faint to be seen with the unaided eye. It is surrounded by a protoplanetary disk marked by dark bands visible in submillimeter radiation that may indicate a number of planets in the process of formation. It is accompanied by the Herbig–Haro object HH 150, a jet of gas emitted along the rotational axis of the disk that is colliding with nearby interstellar dust and gas.
Westerhout 40 or W40 is a star-forming region in the Milky Way located in the constellation Serpens. In this region, interstellar gas forming a diffuse nebula surrounds a cluster of several hundred new-born stars. The distance to W40 is 436 ± 9 pc, making it one of the closest sites of formation of high-mass O-type and B-type stars. The ionizing radiation from the massive OB stars has created an H II region, which has an hour-glass morphology.
MWC 480 is a single star, about 500 light-years away in the constellation of Auriga. It is located in the Taurus-Auriga Star-Forming Region. The name refers to the Mount Wilson Catalog of B and A stars with bright hydrogen lines in their spectra. With an apparent magnitude of 7.62, it is too faint to be seen with the naked eye.
Phi Fornacis is a single star in the southern constellation of Fornax. It has a white hue and is faintly visible to the naked eye with an apparent visual magnitude of 5.13. The distance to this object is approximately 154 light-years based on parallax, and it is drifting further away with a radial velocity of +19 km/s.
LkCa 15 is a T Tauri star in the Taurus Molecular Cloud. These types of stars are relatively young pre-main-sequence stars that show irregular variations in brightness. It has a mass that is about 97% of the Sun, an effective temperature of 4370 K, and is slightly cooler than the Sun. Its apparent magnitude is 11.91, meaning it is not visible to the naked eye.
In infrared astronomy, the J band refers to an atmospheric transmission window centred on 1.25 micrometres.
GG Tauri, often abbreviated as GG Tau, is a quintuple star system in the constellation Taurus. At a distance of about 450 light years away, it is located within the Taurus-Auriga Star Forming Region. The system comprises three stars orbiting each other in a hierarchical triple system, known as GG Tauri A, and another binary star system more distant from the central system, known as GG Tauri B.
A circumplanetary disk is a torus, pancake or ring-shaped accumulation of matter composed of gas, dust, planetesimals, asteroids or collision fragments in orbit around a planet. They are reservoirs of material out of which moons may form. Such a disk can manifest itself in various ways.
GK Tauri is a young binary system composed of T Tauri-type pre-main sequence stars in the constellation of Taurus about 466 light years away, belonging to the Taurus Molecular Cloud.
LDN 1641 or Lynds 1641 is a dark cloud in the constellation Orion. It encompasses a large part of the Orion A molecular cloud in the Orion molecular cloud complex, which is the closest giant molecular cloud to earth. At its northern end it is connected to the Orion Nebula and at its southern end it is connected to the dark cloud LDN 1647. LDN 1641 contains more than a thousand young stellar objects (YSOs). It is a relative low density star-forming region without any massive O- or B-type stars that could disturb the formation of young stars with their ultraviolet radiation. This means that researchers can study star formation that is happening in a very different environment when compared to the Orion Nebula.
IRAS 04125+2902 is a M-type star and a T Tauri variable located in the Taurus Molecular Cloud, 160 parsecs from Earth. This young protostar has 70% of the Sun's mass, 1.45 times the Sun's radius and an effective temperature of 4,080 K. It has a very young age of three million years. It is surrounded by a transitional disk, inclined at 30° relative to Earth, and has one known exoplanet.
KPNO-Tau 12 is a low-mass brown dwarf or free-floating planetary-mass object that is surrounded by a protoplanetary disk, actively accreting material from it.