| SDSS J081421.68+522410.0 | |
|---|---|
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| Observation data (J2000.0 epoch) | |
| Constellation | Lynx |
| Right ascension | 08h 14m 21.68s |
| Declination | +52° 24′ 10.08″ |
| Redshift | 0.24674±0.00006 |
| Heliocentric radial velocity | 73,969.90±17.69 km/s |
| Galactocentric velocity | 74,013±18 km/s |
| Distance | 3.5 billion light-years (1.1 Gpc) |
| Apparent magnitude (V) | 17.16 |
| Characteristics | |
| Type | E (purported with 89% chance)[1] |
| Mass | 2.4×1011 M☉ |
| Size | 242,700 ly (74.40 kpc) (diameter; 25.0 r-mag/arcsec2) |
| Notable features | Giant radio galaxy |
| Other designations | |
| Alcyoneus, 2MASS J08142169+5224103, WISEA J081421.70+522410.0 | |
References: [2] | |
Alcyoneus is a low-excitation, Fanaroff–Riley class II radio galaxy located 3.5 billion light-years (1.1 gigaparsecs) from Earth, with host galaxy SDSS J081421.68+522410.0.[2] It is located in the constellation Lynx and it was discovered in Low-Frequency Array (LOFAR) data by a team of astronomers led by Martijn Oei. As of 2024, it has the second-largest extent of radio structure of any radio galaxy identified, with lobed structures spanning 5 megaparsecs (16 million light-years) across, described by its discoverers at the time as the "largest known structure of galactic origin."[1][a] It has since been superseded by another radio galaxy, Porphyrion, with lobed structures of 7 megaparsecs (23 million light-years).[3][4]
Aside from the size of its radio emissions, the central galaxy is otherwise of ordinary radio luminosity, stellar mass, and supermassive black hole mass. It is a standalone galaxy with an isophotal diameter at 25.0 r-mag/arcsec2 of about 242,700 light-years (74.40 kpc), with the nearest cluster located 11 million light years away from it.[1] The galaxy was named after the giant Alcyoneus from Greek mythology.[1][5]
- ^ a b c d Cite error: The named reference
Oei2022was invoked but never defined (see the help page). - ^ a b Cite error: The named reference
nedwas invoked but never defined (see the help page). - ^ Oei, Martijn S. S. L.; Hardcastle, Martin J.; Timmerman, Roland; Gast, Aivin R. D. J. G. I. B.; Botteon, Andrea; Rodriguez, Antonio C.; Stern, Daniel; Calistro Rivera, Gabriela; Van Weeren, Reinout J.; Röttgering, Huub J. A.; Intema, Huib T.; De Gasperin, Francesco; Djorgovski, S. G. (2024-09-18). "Black hole jets on the scale of the cosmic web". Nature. 633: 537–541. doi:10.1038/s41586-024-07879-y.
- ^ Will Dunham (2024-09-18). "Faraway black hole unleashes record-setting energetic jets". Reuters.
- ^ "Somerville student names newly-discovered largest known radio galaxy". Somerville College, some.ox.ac.uk. 2022-02-21.
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