NGC 1514

NGC 1514, also known as the Crystal Ball Nebula,^[3] is a planetary nebula in the zodiac constellation of Taurus,^[2] positioned to the north of the star Psi Tauri along the constellation border with Perseus.^[4] Distance to the nebula is 466 pc, according to GAIA DR2 data.^{[full citation needed]}

NGC 1514

Emission nebula
Planetary nebula
Observation data: J2000 epoch
Right ascension	04h 09m 16.98573s[1]
Declination	+30° 46′ 33.4699″[1]
Distance	1520 ly
Apparent magnitude (V)	9.27
Apparent dimensions (V)	2.2′[2]
Constellation	Taurus
Physical characteristics
Radius	0.5[citation needed] ly
See also: Lists of nebulae

It was discovered by William Herschel on November 13, 1790, describing it as "a most singular phenomenon" and forcing him to rethink his ideas on the construction of the heavens. Up until this point Herschel was convinced that all nebulae consisted of masses of stars too remote to resolve, but now here was a single star "surrounded with a faintly luminous atmosphere". He concluded: "Our judgement I may venture to say, will be, that the nebulosity about the star is not of a starry nature."^[5][6]

This is a double-shell nebula that is described as, "a bright roundish amorphous PN" with a radius of around 65″ and a faint halo that has a radius of 90″.^[7] It consists of an outer shell, an inner shell, and bright blobs.^[8] The inner shell appears to be distorted, but was likely originally spherical.^[9] An alternative description is of "lumpy nebula composed of numerous small bubbles" with a somewhat filamentary structure in the outer shell.^[6] Infrared observations show a huge region of dust surrounds the planetary nebula, spanning 8.5 ly (2.6 pc). There is also a pair of rings forming what appears to be a diabolo-like structure, similar to those found in MyCn 18, but these are extremely faint and only visible in the mid-infrared,^[9] The combined mass of the gas and dust is estimated at 2.2±1.4 M_☉^[7] The ionized gas is moderately excited, and the electron temperature is estimated to be 15,000 K.^[9]

The nebula originated from a binary star system with the designation HD 281679 from the Henry Draper Catalogue.^[10] The bright, visible component is a giant star on the horizontal branch with a stellar classification of A0III, while the nebula-generating companion is now a hot, sub-luminous O-type star.^[6] The two were originally thought to have an orbital period on the order of 10 days,^[8] but observations of the system over years showed that their orbit is actually one of the longest known for any planetary nebula, with a period of about 9 years.^[11] Their orbital eccentricity is about 0.5.^[11]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
2. Finlay, Warren H. (2014), Concise Catalog of Deep-sky Objects, The Patrick Moore Practical Astronomy Series (2nd ed.), Springer Science & Business Media, p. 177, ISBN 978-3-319-03169-9.
3. Stoyan, Ronald; Schurig, Stephan (2014). interstellarum Deep Sky Atlas. Erlangen: Cambridge University Press; Oculum-Verlag GmbH. ISBN 978-1-107-50338-0. OCLC 920437579.
4. Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. Vol. 1. Sky Publishing Corporation and the European Space Agency. ISBN 0-933346-84-0.
5. Herschel, William (February 10, 1791), "On Nebulous Stars, Properly So Called.", Philosophical Transactions of the Royal Society, 81: 71–88, Bibcode:1791RSPT...81...71H, doi:10.1098/rstl.1791.0006, S2CID 186209286.
6. Ressler, Michael E.; et al. (December 2010), "The Discovery of Infrared Rings in the Planetary Nebula NGC 1514 During the WISE All-sky Survey", The Astronomical Journal, 140 (6): 1882–1890, arXiv:1011.3877, Bibcode:2010AJ....140.1882R, doi:10.1088/0004-6256/140/6/1882, S2CID 31272682.
7. Aryal, B.; et al. (February 2010), "A giant dusty bipolar structure around the planetary nebula NGC 1514", Monthly Notices of the Royal Astronomical Society, 402 (2): 1307–1312, Bibcode:2010MNRAS.402.1307A, doi:10.1111/j.1365-2966.2009.15966.x.
8. Muthu, C.; Anandarao, B. G. (December 2003), "A Spatiokinematic Study of the Planetary Nebula NGC 1514", The Astronomical Journal, 126 (6): 2963–2970, Bibcode:2003AJ....126.2963M, doi:10.1086/379552.
9. Aller, A.; Vázquez, R.; Olguín, L.; Miranda, L. F.; Ressler, M. E. (2021), "The morpho-kinematical structure and chemical abundances of the complex planetary nebula NGC 1514", Monthly Notices of the Royal Astronomical Society, 504 (4): 4806–4816, arXiv:2105.01495, doi:10.1093/mnras/stab1233.
10. "NGC 1514". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-08-15.
11. Jones, D.; Van Winckel, H.; Aller, A.; Exter, K.; De Marco, O. (2017). "The long-period binary central stars of the planetary nebulae NGC 1514 and LoTr 5". Astronomy & Astrophysics. 600: L9. arXiv:1703.05096. Bibcode:2017A&A...600L...9J. doi:10.1051/0004-6361/201730700. S2CID 55371290.

External links

• Basic data on NGC 1514
• Discussion on the dynamics of the NGC 1514 system Archived 2012-10-25 at the Wayback Machine