SBS 1415+437

SBS 1415+437 is a blue compact dwarf galaxy and Wolf-Rayet galaxy located in the constellation Boötes. It is approximately 45.3 million light-years away from the Milky Way, and was discovered in 1995 by a team of astronomers from the University of Virginia coordinated by Trinh Thuan.^[1]

SBS 1415+437
Observation data (J2000 epoch)
Constellation	Boötes
Right ascension	14h 27m 01.68s
Declination	+43° 30′ 22.88″
Redshift	0.002055
Heliocentric radial velocity	616 km/s
Distance	45.3 million ly
Apparent magnitude (B)	15.6
Characteristics
Type	Dwarf galaxy
Size	10,000 ly
Apparent size (V)	0.75' x 0.15'
Other designations
PGC 51017, SBSG 1415+437, SDSS CGB 12067.1

It was initially thought that the galaxy hosted only very young stars, but the stars were later found to be up to 1.3 billion years old.^[1][2][3]

SBS 1415+437 is also a starburst galaxy of the rare Wolf-Rayet type, as it contains an unusually large number of Wolf-Rayet stars. These are massive stars (at least 20 solar masses), short-lived, with surface temperatures of over 25,000 kelvin which, due to very strong stellar winds (over 2,000 km/s), lose large quantities of their mass (in about 100,000 years a Wolf-Rayet star can lose the equivalent of the mass of the Sun).^[4][1][5] It is said the galaxy hosted a number of Red-giant branch stars apart from Wolf-Rayets as well.^[6]

In 2019, astronomers found there are traces of ionized gas inside the star-forming regions of SBS 1415+437, hinting the presence of elemental abundances of chemical elements such as nitrogen, argon and sulfur.^[7]

See also

• List of galaxies
• Kiso 5639, a similar dwarf galaxy

References

1. Guseva, N. G. (May 16, 2003). "Spectroscopic and photometric studies of low-metallicity star-forming dwarf galaxies" (PDF). AaNDA. Retrieved July 22, 2024.
2. "Hubble Sees an Intriguing Young-Looking Dwarf Galaxy - NASA Science". science.nasa.gov. Retrieved 2024-07-22.
3. Thuan, Trinh X.; Izotov, Yuri I.; Foltz, Craig B. (November 1999). "The Young Age of the Extremely Metal-deficient Blue Compact Dwarf Galaxy SBS 1415+437". The Astrophysical Journal. 525 (1): 105–126. arXiv:astro-ph/9905345. Bibcode:1999ApJ...525..105T. doi:10.1086/307877. ISSN 0004-637X.
4. López-Sánchez, A. R.; Esteban, C. (2009-12-01). "Massive star formation in Wolf-Rayet galaxies - II. Optical spectroscopy results". Astronomy & Astrophysics. 508 (2): 615–640. arXiv:0910.1578. Bibcode:2009A&A...508..615L. doi:10.1051/0004-6361/200912042. ISSN 0004-6361.
5. [e-mail]. "Intense and short-lived". www.esahubble.org. Retrieved 2024-07-22.
6. Aloisi, A.; van der Marel, R. P.; Mack, J.; Leitherer, C.; Sirianni, M.; Tosi, M. (2005-09-01). "Do Young Galaxies Exist in the Local Universe? Red Giant Branch Detection in the Metal-poor Dwarf Galaxy SBS 1415+437". The Astrophysical Journal. 631 (1): L45–L48. arXiv:astro-ph/0508484. Bibcode:2005ApJ...631L..45A. doi:10.1086/497112. ISSN 0004-637X.
7. Kumari, Nimisha; James, Bethan L; Irwin, Mike J; Aloisi, Alessandra (2019-02-05). "Small-scale chemical abundance analysis in a blue compact dwarf galaxy SBS 1415+437". Monthly Notices of the Royal Astronomical Society. 485 (1): 1103–1120. arXiv:1901.08600. doi:10.1093/mnras/stz343. ISSN 0035-8711.