Hubble 12
| Emission nebula | |
|---|---|
| Planetary nebula | |
| Infrared image by the Hubble Space Telescope | |
| Observation data: J2000 epoch | |
| Right ascension | 23h 26m 14.82s[1] |
| Declination | 58°10′54.65′′[1] |
| Distance | 7,305-46,477[2] ly |
| Apparent diameter | ~10"[3] |
| Constellation | Cassiopeia |
| Designations | PN G111.8-02.8[1] |
| See also: Lists of nebulae | |
Hubble 12 (Hb 12) is a bipolar planetary nebula with an hourglass like shape. The nebula has three pairs of bipolar lobes.
Nomenclature
[edit ]Hubble 12 (Hb 12 for short) was discovered by American astronomer Edwin Hubble in 1921.[4]
Characteristics
[edit ]Hb 12 has three pairs of bipolar lobes with a faint Hα arc filament.[3] Additionally, the outermost lobe is fainter on the eastern side than on the western side, which may indicate less dense regions on the eastern side of the PN.[5]
The distance of Hb 12 is estimated to be ~2.24 kpc to ~14.25 kpc.[2] A zone with a high electron density of ~5x105 cm-3 corresponds to an electron temperature of ~13,600 K.[5] A shocked [Fe II] line was found in the bipolar structures near the core.[6]
The central star
[edit ]The central star of Hb 12 has an estimated temperature of ~35,000 K and a luminosity of ~1200 L⊙.[5] The appearance of highly structured bipolar lobes with two pairs of H2 knots[7] [8] suggests that multiple pulsed mass-loss episodes have occurred during the AGB or post-AGB phases.[9] [10]
References
[edit ]- 1 2 3 "PN Hb 12". simbad.cds.unistra.fr.
- 1 2 Stanghellini, L.; Haywood, M. (May 2010). "The Galactic Structure and Chemical Evolution Traced by the Population of Planetary Nebulae". The Astrophysical Journal. 714 (2): 1096–1107. arXiv:1003.0759 . Bibcode:2010ApJ...714.1096S. doi:10.1088/0004-637X/714/2/1096.
- 1 2 Kowk, S.; Hsia, C.-H. (May 2007). "Multiple Coaxial Rings in the Bipolar Nebula Hubble 12". The Astrophysical Journal. 660 (1): 341–345. Bibcode:2007ApJ...660..341K. doi:10.1086/513096.
- ↑ Hubble, E. (June 1921). "Twelve New Planetary Nebulae". Publications of the Astronomical Society of Japan. 33 (193): 174. Bibcode:1921PASP...33..174H. doi:10.1086/123070.
- 1 2 3 Hyung, S.; Aller, L. H. (January 1996). "The optical spectrum of the young planetary nebula Hubble 12". Monthly Notices of the Royal Astronomical Society. 278 (2): 551–564. Bibcode:1996MNRAS.278..551H. doi:10.1093/mnras/278.2.551 .
- ↑ Frank, A.; Welch, C. A.; Pipher, J. L.; Woodward, C. E.; Forrest, W. J. (September 1990). "[Fe II] Bubbles in the Young Planetary Nebula Hubble 12". The Astrophysical Journal. 512 (1): L69–L72. Bibcode:1999ApJ...522L..69W. doi:10.1086/312206.
- ↑ Hsia, C.-H.; Zhang, Y.; Kowk, S.; Chau, W. (February 2019). "A young multipolar planetary nebula in the making—IRAS 21282+5050". Astrophysics and Space Science. 364 (2): 13–32. arXiv:1902.08851 . Bibcode:2019Ap&SS.364...32H. doi:10.1007/s10509-019-3523-2.
- ↑ Fang, X.; Kowk, S.; Zhang, Y.; Hisa, C.-H.; Chau, W.; Ramos-Larios, G.; Guerrero, M. A. (June 2018). "Extended Structures of Planetary Nebula Detected in H2 Emission". The Astrophysical Journal. 859 (2): 23–92. arXiv:1804.08840 . Bibcode:2018ApJ...859...92F. doi:10.3847/1538-4357/aac01e .
- ↑ Clark, D. M.; Edwards, M. L.; López, J. A.; Winge, C. (November 2014). "A Detailed Study of the Structure of the Nested Planetary Nebula, Hb 12, the Matryoshka Nebula". The Astrophysical Journal. 148 (5): 9–98. Bibcode:2014AJ....148...98C. doi:10.1088/0004-6256/148/5/9898, 9 pp.
{{cite journal}}: CS1 maint: postscript (link) - ↑ Vaytet, N. M. H.; Rushton, A. P.; Lloyd, M.; López, J. A.; Meaburn, J.; O'Brien, T. J.; Mitchell, D. L.; Pollacco, D. (September 2009). "High-speed knots in the hourglass-shaped planetary nebula Hubble 12". Monthly Notices of the Royal Astronomical Society. 398 (1): 385–393. arXiv:0905.4625 . Bibcode:2009MNRAS.398..385V. doi:10.1111/j.1365-2966.2009.15149.x .