ETHOS 1
| Emission nebula | |
|---|---|
| Planetary nebula | |
| Observation data: J2000 epoch | |
| Right ascension | 19h 16m 31.5s[1] |
| Declination | 36° 09′ 47.9″[1] |
| Distance | 19,500±27,500 ly |
| Apparent diameter | ~62.6" (jets) ~19.4" (main)[2] |
| Constellation | Lyra |
| Designations | ATO J289.1311+36.1632,PN G068.1+11.0[1] |
ETHOS 1 is a high-latitude planetary nebula in the constellation of Lyra. This nebula is notable for possessing fast polar jets.
Nomenclature
[edit]Commonly known as ETHOS 1. Which stands for the Extremely Turquoise Halo Object Survey. And is also the first planetary nebula discovered by the ETHOS.
Properties
[edit]ETHOS 1 is a High latitude planetary nebula. fewer than 9 percent of Galactic PNe are located at latitudes |b| ≳ 10°.
Main/Inner nebula
[edit]The inner nebula features major emission lines such as [O III] and Hβ. Which has a diameter of ~19.4 arcsec and the inner nebula has a kinematical age of 900±100 yr kpc-1. The main nebula has a high electron temperature of 17,700±500 K.[3] The [N II] emission line extends out to ~2 arcsec, which represents the outermost reigon.[4] There is also a He II line that is much brighter than Hβ line. Which is a clear indication that the nebula is density-bounded. But the ionized mass of the nebula is strikingly low at ~0.002.
The polar jets
[edit]ETHOS 1 has 2 polar outflows (jets) traveling at 120±10 km sec-1. The NW jet has a velocity of 65±5 km s-1, while the SE jet has a velocity of -55±5 km s-1. The jet has a diameter of 62.6 arcsec, and the kinematical ages of these jets is estimated to be 1750±250 yr kpc-1. The presence of [O III] in the jet and its relatively low Te = 12,900 K indicate that strong, radiative cooling is occurring in the post-shock region.[5] A He I line was identified in the SE jet.
Binary star system
[edit]The central star is a close binary central star of PNe (CSPN) that shows evidence of passing through a common-envelope (CE) phase.[6] The central star is a ∼140-kK pre-white dwarf with a mass of ∼0.84 M⊙. making it one of the hottest and most massive post-CE central star known.[7]
References
[edit]- 1 2 3 "ATO J289.1311+36.1632". simbad.cds.unistra.fr.
- ↑ Miszalski, B.; Corradi, R.L.M; Jones, D.; Santander-García, M.; Rodríguez-Gil, P.; Rubio-Díez, M.M. Asymmetric Planetary Nebulae V.
- ↑ Shaw, R.A.; Dufour, R.J. (September 1995). "Software for the Analysis of Emission Line Nebulae". Publications of the Astronomical Society of Japan. 107: 896. Bibcode:1995PASP..107..896S. doi:10.1086/133637.
- ↑ Raga, A.C.; Cantó, J.; Biro, S. (1 January 1993). "Ballistic stellar jets from sources with a time-dependent ejection direction". Monthly Notices of the Royal Astronomical Society. 260 (1): 163–170.
- ↑ Dopita, M.A. (August 1997). "What Excites FLIERS?". The Astrophysical Journal. 485 (1): L41-44. Bibcode:1997ApJ...485L..41D. doi:10.1086/310804.
- ↑ De Marco, O.; Hillwig, T.C.; Smith, A.J. (July 2008). "Binary Central Stars of Planetary Nebulae Discovered Through Photometric Variability. I. What we Know and what we would like to Find Out". The Astronomical Journal (1): 323–336. Bibcode:2008AJ....136..323D. doi:10.1088/0004-6256/136/1/323.
- ↑ Acker, A.; Miszalski, B.; Moffat, A.F.J. (March 2009). "Binary planetary nebulae nuclei towards the Galactic bulge. I. Sample discovery, period distribution, and binary fraction". Astronomy & Astrophysics. 496 (3): 813–825. Bibcode:2009A&A...496..813M. doi:10.1051/0004-6361/200811380.