NGC 1501

NGC 1501
Emission nebula
Planetary nebula
	As seen from the Hubble Space Telescope
Observation data: J2000 epoch
Right ascension	04h 06m 59.39s
Declination	+60° 55′ 14.4″
Distance	est. 4,240 ly (1.30 kpc) ly
Apparent magnitude (V)	13.0
Apparent dimensions (V)	0.863' (diameter)
Constellation	Camelopardalis
Physical characteristics
Radius	0.5 ly
Designations	PK 144+6.1, PN G 144.5+06.5, GC 801, CS 14.4, H 4.53
	See also: Lists of nebulae

NGC 1501 (also known as the Camel's Eye Nebula^[3] or the Oyster Nebula^[4]) is a complex planetary nebula located in the constellation of Camelopardalis, it was discovered on 27 August 1787 by William Herschel.^[2]^[5]

Properties

The central star of the planetary nebula has a spectral type of [WC4], similar to that of a carbon-rich Wolf–Rayet star.^[6] It is a pulsating star, meaning that its brightness varies regularly and periodically. In the case of NGC 1501's progenitor star, this is incredibly fast, with the star's brightness changing significantly in just half an hour. An analysis of Gaia data suggests that the central star is a binary system.^[7] Visible-light observations capture the glow of gases including hydrogen and nitrogen.^[8] The total mass of the nebula is estimated to be around 0.22 M_☉, most of which is ionized gas (0.21 M_☉) and a small fraction (8.9×10⁻⁴ M_☉) is carbon-rich dust.^[9]

Gallery

The location of NGC 1501 (circled in red)
NGC 1501 from the 0.8m Schulman Telescope at the Mount Lemmon SkyCenter

References

^ ^a ^b ^c "SIMBAD Astronomical Database". NGC 1501. Retrieved 9 November 2014.
^ ^a ^b Sabbadin, F.; Benetti, S.; Cappellaro, E.; Turatto, M. (2000). "The tetra-lobed planetary nebula NGC 1501". Astronomy and Astrophysics. 361: 1112–1120. arXiv:astro-ph/0007039. Bibcode:2000A&A...361.1112S.
^ Stoyan, Ronald; Schurig, Stephan (2014). interstellarum Deep Sky Atlas. Erlangen: Cambridge University Press; Oculum-Verlag GmbH. ISBN 978-1-107-50338-0. OCLC 920437579.
^ "Hubble View of Bubbly Nebula". 17 April 2015. Retrieved 8 December 2016.
^ Seligman, Courtney. "Celestial Atlas: NGC Objects: NGC 1500 - 1549". cseligman.com. Archived from the original on 1 January 2016. Retrieved 10 July 2015.
^ González-Santamaría, I.; Manteiga, M.; Manchado, A.; Ulla, A.; Dafonte, C.; López Varela, P. (2021). "Planetary nebulae in Gaia EDR3: Central star identification, properties, and binarity". Astronomy & Astrophysics. 656: A51. arXiv:2109.12114. Bibcode:2021A&A...656A..51G. doi:10.1051/0004-6361/202141916. S2CID 237940344.
^ Chornay, N.; Walton, N. A.; Jones, D.; Boffin, H. M. J.; Rejkuba, M.; Wesson, R. (2021). "Towards a more complete sample of binary central stars of planetary nebulae with Gaia". Astronomy & Astrophysics. 648: A95. arXiv:2101.01800. Bibcode:2021A&A...648A..95C. doi:10.1051/0004-6361/202140288. S2CID 230770301.
^ "Oyster Nebula NGC 1501 As Seen By Hubble - SpaceRef". spaceref.com. 7 September 2016. Retrieved 8 February 2021.^{[permanent dead link‍]}
^ Rubio, G.; Toalá, J. A.; Todt, H.; Sabin, L.; Santamaría, E.; Ramos-Larios, G.; Guerrero, M. A. (2022). "Planetary nebulae with Wolf–Rayet-type central stars – IV. NGC 1501 and its mixing layer". Monthly Notices of the Royal Astronomical Society. 517 (4): 5166–5179. arXiv:2210.09116. Bibcode:2022MNRAS.517.5166R. doi:10.1093/mnras/stac3011.