An Etymological Dictionary of Astronomy and Astrophysics

One of the most massive → star formation regions in the → Galaxy, situated in the constellation → Aquila at the junction point of the → Galactic bar and the → spiral arms. It lies at a distance of about 6 kpc from the Sun and covers a vast area of the → Galactic plane with l = (29° to 32°) and b = (-1° to + 1°).

W 43 is a complex of more than 20 → molecular clouds in ¹³CO emission with systemic velocities ranging from 12 km s^-1 to 110 km s^-1. The total → virial mass is estimated to be several 10⁶Msun.

Close to its center, W 43-Main is undergoing a remarkably efficient episode of → star formation and qualifies as a mini-starburst Among the 15 dense cores of W 43-Main (0.2 pc FWHM size and 5 × 10⁵ cm^-3 density), three extremely massive, → dense cores are potentially forming → massive stars: W 43-MM1 (M = 3600 Msun), W 43-MM2 (M = 1600 Msun), and W 43-MM3 (M = 1000 Msun). Adjacent to W 43-Main is a → giant H II region, illuminated by a cluster of → Wolf-Rayet and → OB stars, emitting ~ 10⁵¹ → Lyman continuum photons per second and a → far-infrared  → continuum luminosity of ~ 3.5 × 10⁶  Lsun. It is not yet clear what the impact is of this → starburst cluster on the W 43-Main cloud located 2-10 pc away. With its special characteristics, W 43 represents a type of molecular cloud complex which hosts high luminosity embedded clusters. Other well-known examples are W 49 and W 51 (e.g., Nguyen Luong et., 2013, arXiv:1306.0547).

See also: Number 43 in the following catalog: Gart Westerhout, 1958, Bull. Astron. Inst. Netherlands, 14, 215, A survey of the continuous radiation from the galactic system at a frequency of 1390 Mc/s.

One of the most massive → star formation regions in the → Galaxy, situated in the constellation → Aquila at the junction point of the → Galactic bar and the → spiral arms. It lies at a distance of about 6 kpc from the Sun and covers a vast area of the → Galactic plane with l = (29° to 32°) and b = (-1° to + 1°).

W 43 is a complex of more than 20 → molecular clouds in ¹³CO emission with systemic velocities ranging from 12 km s^-1 to 110 km s^-1. The total → virial mass is estimated to be several 10⁶Msun.

Close to its center, W 43-Main is undergoing a remarkably efficient episode of → star formation and qualifies as a mini-starburst Among the 15 dense cores of W 43-Main (0.2 pc FWHM size and 5 × 10⁵ cm^-3 density), three extremely massive, → dense cores are potentially forming → massive stars: W 43-MM1 (M = 3600 Msun), W 43-MM2 (M = 1600 Msun), and W 43-MM3 (M = 1000 Msun). Adjacent to W 43-Main is a → giant H II region, illuminated by a cluster of → Wolf-Rayet and → OB stars, emitting ~ 10⁵¹ → Lyman continuum photons per second and a → far-infrared  → continuum luminosity of ~ 3.5 × 10⁶  Lsun. It is not yet clear what the impact is of this → starburst cluster on the W 43-Main cloud located 2-10 pc away. With its special characteristics, W 43 represents a type of molecular cloud complex which hosts high luminosity embedded clusters. Other well-known examples are W 49 and W 51 (e.g., Nguyen Luong et., 2013, arXiv:1306.0547).

See also: Number 43 in the following catalog: Gart Westerhout, 1958, Bull. Astron. Inst. Netherlands, 14, 215, A survey of the continuous radiation from the galactic system at a frequency of 1390 Mc/s.

A → boson particle that, along with → Z boson, mediates the → weak force in particle interactions. Two kinds of W bosons exist, the W⁺ and its antiparticle W^-. With a mass of 80.4 GeV/c², the W boson is almost 100 times as massive as the → proton.

See also: W for → weak; → boson.

A → boson particle that, along with → Z boson, mediates the → weak force in particle interactions. Two kinds of W bosons exist, the W⁺ and its antiparticle W^-. With a mass of 80.4 GeV/c², the W boson is almost 100 times as massive as the → proton.

See also: W for → weak; → boson.

A member of a class of → pulsating stars with a period of 1 to 35 days located in the → instability strip of the → H-R diagram. Also known as type II Cepheid variables, W Virginis stars are typically 1.5 mag fainter than classical Type I Cepheids and have
a mass less than that of the Sun. They also exhibit a period-luminosity relation which is distinct, but works in a similar way to the relation for Type I Cepheids. Hence W Virginis stars can also be used to measure Galactic and extragalactic distances.

See also: W, alphabetical letter; → variable star designation; → Virgo; → star.

A member of a class of → pulsating stars with a period of 1 to 35 days located in the → instability strip of the → H-R diagram. Also known as type II Cepheid variables, W Virginis stars are typically 1.5 mag fainter than classical Type I Cepheids and have
a mass less than that of the Sun. They also exhibit a period-luminosity relation which is distinct, but works in a similar way to the relation for Type I Cepheids. Hence W Virginis stars can also be used to measure Galactic and extragalactic distances.

See also: W, alphabetical letter; → variable star designation; → Virgo; → star.

Short for → Wolf-Rayet.

See also: → Wolf-Rayet star.

Short for → Wolf-Rayet.

See also: → Wolf-Rayet star.

Short for → Wolf-Rayet star.

See also: → Wolf-Rayet star.

Short for → Wolf-Rayet star.

See also: → Wolf-Rayet star.

The most luminous → galaxy known. It has a → redshift of z = 4.601 and a → bolometric luminosity of 3.5 × 10¹⁴Lsun. W2246-0526 hosts a deeply buried → active galactic nucleus (AGN)/→ supermassive black hole (SMBH). Discovered using the → Wide-field Infrared Survey Explorer (WISE), W2246-0526 is classified as a → hot dust-obscured galaxy, based on its → luminosity and → dust temperature (T. Diaz-Santos et al. 2015, arXiv:1511.04079).

See also: Object designation from → Wide-field Infrared Survey Explorer (WISE).

The most luminous → galaxy known. It has a → redshift of z = 4.601 and a → bolometric luminosity of 3.5 × 10¹⁴Lsun. W2246-0526 hosts a deeply buried → active galactic nucleus (AGN)/→ supermassive black hole (SMBH). Discovered using the → Wide-field Infrared Survey Explorer (WISE), W2246-0526 is classified as a → hot dust-obscured galaxy, based on its → luminosity and → dust temperature (T. Diaz-Santos et al. 2015, arXiv:1511.04079).

See also: Object designation from → Wide-field Infrared Survey Explorer (WISE).