Astronomy:Sh 2-68
| Nebula | |
|---|---|
 Image of Sh 2-68 Nebula | |
| Observation data: epoch | |
| Right ascension | 18h 24m 58.43s[1] |
| Declination | +00° 51′ 36.0″[1] |
| Distance | 350 pc |
| Constellation | Serpens |
| Physical characteristics | |
| Dimensions | 8'[2] |
| Designations | Sh 2-68, LBN 93, PN G030.6+06.2[1] |
Sh 2-68 (also known as Flaming Skull Nebula) is a planetary nebula located in the constellation Serpens. It is the remnant of a low to intermediate mass star that has shed its outer layers, leaving behind a glowing shell of ionized gas illuminated by its central white dwarf star. Estimated to be 30,000 to 45,000 years old, Sh 2-68 is notable for its interaction with the surrounding interstellar medium (ISM), which has stalled the nebula's expansion and created an extended tail structure, giving it a distinctive asymmetrical appearance.[3][4][5]
It has a proper motion of 53.2 +/- 5.5 mas yr-1, the largest value for a planetary nebula ever found.[6]
Central star
The central star of Sh 2-68 is a hot white dwarf designated WD 1822+008 with a spectral type DAOZ.6, indicating strong absorption lines from hydrogen and helium in a hot atmosphere. The star appears as a blue point source offset from the nebula's center, embedded in the oxygen-rich core.[7][1][4][8]
References
- ↑ 1.0 1.1 1.2 1.3 "Simbad - Object view". https://simbad.cds.unistra.fr/mobile/object.html?object_name=Sh%202-68.
- ↑ "CCD Images of the Sharpless Catalog". http://www.sharplesscatalog.com/sharpless.aspx.
- ↑ info@noirlab.edu. "Planetary Nebula Sh2-68" (in en). https://www.noirlab.edu/public/images/noao-sh2-68/.
- ↑ 4.0 4.1 "Sh 2-68". http://galaxymap.org/cat/view/sharpless/68.
- ↑ Kerber, F.; Guglielmetti, F.; Mignani, R.; Roth, M. (January 2003). "Sh 2-68 – A Planetary Nebula Leaving it's Mark on the Interstellar Medium" (in en). Symposium - International Astronomical Union 209: 525–526. doi:10.1017/S007418090020956X. ISSN 0074-1809. https://www.cambridge.org/core/journals/symposium-international-astronomical-union/article/sh-268-a-planetary-nebula-leaving-its-mark-on-the-interstellar-medium/DB9BB8BB36B23033F8009D6815C703BC.
- ↑ Kerber, F.; Guglielmetti, F.; Mignani, R.; Roth, M. (2002). "Proper motion of the central star of the Planetary Nebula Sh 2-68". Astronomy and Astrophysics 381: L9–L12. doi:10.1051/0004-6361:20011546. Bibcode: 2002A&A...381L...9K. https://ui.adsabs.harvard.edu/abs/2002A%26A...381L...9K/abstract.
- ↑ REFoster61. "PN G 030.6+06.2 and SH 2-68 - astrophotography by REFoster61" (in en). https://telescopius.com/pictures/view/201228/sh-2-68/sh2-68/by-refoster61.
- ↑ Kerber, F.; Guglielmetti, F.; Mignani, R.; Roth, M. (2002-01-01). "Proper motion of the central star of the Planetary Nebula Sh 2–68" (in en). Astronomy & Astrophysics 381 (1): L9–L12. doi:10.1051/0004-6361:20011546. ISSN 0004-6361. Bibcode: 2002A&A...381L...9K. https://www.aanda.org/articles/aa/abs/2002/01/aadi244/aadi244.html.
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