| Bean Galaxy | |
|---|---|
| 👁 Image DESI Legacy Surveys DR9 photo of the Bean Galaxy. | |
| Observation data (J2000 epoch) | |
| Constellation | Draco |
| Right ascension | 17h 15m 30.04s |
| Declination | +64° 39' 51.61" |
| Redshift | 0.07898 |
| Heliocentric radial velocity | 22745 |
| Distance | 1.089 bly (334 mpc) |
| Group or cluster | SDSS-C4 3089 |
| magnitude (K) | 11.568 |
| Characteristics | |
| Type | cD |
| Mass | 1.349×1012 M☉ |
| Size | 319,000 ly (97,800 pc) |
| Other designations | |
| 7C 1715+6442, LEDA 59953, PGC 59953, WN B1715+6442 | |
The Bean Galaxy, also known as 7C 1715+6442 is a supergiant elliptical galaxy, active galaxy, radio galaxy, and brightest cluster galaxy in the constellation of Draco.[1][2][3] The galaxy is 1.09 billion light years (or 334,000,000 parsecs) away at a spectroscopic redshift of z = 0.07898.[1][2] The galaxy has an apparent K magnitude of 11.568.[1] The Bean Galaxy is the brightest cluster galaxy of SDSS-C4 3089, and this galaxy cluster contains a total of 17 galaxies.[4] The galaxy was discovered in 1980 by the Westerbork Radio Telescope in the 14th list of radio sources.[5]
Characteristics
[edit]The Bean Galaxy is a massive, large supergiant elliptical galaxy in the galaxy cluster, SDSS-C4 3089.[1][2] The galaxy has a total diameter of 319,000 light years (or 97,800 parsecs) across, or roughly three times larger than the Milky Way.[2] The size was estimated using the 2MASS K-band total mag angular diameter of approximately one arcmin (or 60.4 arcsecs), and a redshift-independent distance of 1.09 billion light years (or 334,000,000 parsecs) away.[2]
The Bean Galaxy is thought to be exceptionally massive, having a stellar mass of 1.35 trillion M☉ (or 1012.13).[6] The stellar population of the galaxy is predicted to be old, with an average age of 6.75 billion years old (or 109.829).[7] The stellar population mainly consists of metal-poor red giant branch, and asymptotic giant branch stars.[7] The galaxy has a star-formation rate of 0.235 M☉ per year, typical for gas-poor elliptical galaxies.[8]
The galactic center of the Bean Galaxy has an active galactic nucleus (also referred to as an AGN), which is small region in the galactic center of a galaxy that is very luminous and energetic.[2] The active galactic nucleus is powered by a large supermassive black hole (also known as an SMBH) with a mass of 2.207 billion M☉ estimated using velocity dispersion.[9]
The Bean Galaxy is classified as a giant radio galaxy (also called as an GRG), i. e. a radio galaxy with radio lobes larger than 2.2 million light years (or 700,000 parsecs) across.[9] It was first discovered in 1980 that the Bean Galaxy was a radio galaxy.[5] The radio emissions stretch roughly 3 million light years (or 926,000 parsecs) across, based on an angular diameter of 10 arcmin.[9] These radio lobes are created by the galaxy's massive central black hole.[9] This giant radio galaxy is unusual because it is located in a galaxy cluster, which is rare for giant radio galaxies,[9] and it is similar to other radio galaxies such as Inkathazo in both extent and location.[10]
X-ray source
[edit]One X-ray source has been discovered in the Bean Galaxy: CXOX J171530.1+643950, which is classified as a radio X-ray source, and was discovered in 2024 in a survey of 3.1 million X-ray sources.[11]
References
[edit]- ^ a b c d "SIMBAD Results for Bean Galaxy". SIMBAD. Retrieved 2026-01-10.
- ^ a b c d e f "NED Results for Bean Galaxy". NASA/IPAC Extragalactic Database. Retrieved 2026-01-10.
- ^ Zhao, Dongyao (2015). "The link between morphology and structure of brightest cluster galaxies: automatic identification of cDs". Monthly Notices of the Royal Astronomical Society. 448 (3): 2530. arXiv:1501.06352. Bibcode:2015MNRAS.448.2530Z. doi:10.1093/mnras/stv190.
- ^ "SIMBAD Results for SDSS-C4 3089". SIMBAD. Retrieved 2026-01-10.
- ^ a b Harris, D. E. (1980). "Westerbork synthesis observations of 8 clusters of galaxies which contain tailed radio galaxies". Astronomy and Astrophysics Supplement Series. 39: 215. Bibcode:1980A&AS...39..215H. Retrieved 2026-01-10.
- ^ Mamon, Gary (2020). "The frequency of very young galaxies in the local Universe - II. The view from SDSS spectra". Monthly Notices of the Royal Astronomical Society. 492 (2): 1791. arXiv:1912.06522. Bibcode:2020MNRAS.492.1791M. doi:10.1093/mnras/stz3556.
- ^ a b Mattolini, D. (2025). "Re-assessing the stellar population scaling relations of the galaxies in the Local Universe". Astronomy & Astrophysics. 703: A5. arXiv:2509.04570. Bibcode:2025A&A...703A...5M. doi:10.1051/0004-6361/202554972. Retrieved 2026-01-10.
- ^ Demers, Melanie (2019). "Smaller stellar disc scale lengths in rich environments". Monthly Notices of the Royal Astronomical Society. 489 (2): 2216. arXiv:1908.06810. Bibcode:2019MNRAS.489.2216D. doi:10.1093/mnras/stz2305.
- ^ a b c d e Oei, Martijn (2023). "Measuring the giant radio galaxy length distribution with the LoTSS". Astronomy & Astrophysics. 672: A163. arXiv:2210.10234. Bibcode:2023A&A...672A.163O. doi:10.1051/0004-6361/202243572. Retrieved 2026-01-10.
- ^ Charlton, K. K. L. (2025). "A spatially resolved spectral analysis of giant radio galaxies with MeerKAT". Monthly Notices of the Royal Astronomical Society. 537 (1): 272. arXiv:2411.06813. Bibcode:2025MNRAS.537..272C. doi:10.1093/mnras/stae2543.
- ^ Flesch, Eric (2024). "The Millions of Optical-Radio/X-ray Associations (MORX) Catalogue, v2". The Open Journal of Astrophysics. 7: 6. arXiv:2308.01507. Bibcode:2024OJAp....7E...6F. doi:10.21105/astro.2308.01507.
