WeBo 1
| Emission nebula | |
|---|---|
| Planetary nebula | |
 HaRGB Image of WeBo 1 taken from the Mount Lemmon Sky Center | |
| Observation data: J2000 epoch | |
| Right ascension | 02h 40m 14.37s[1] |
| Declination | +61° 09′ 16.77″[1] |
| Distance | 2772-7175[2] ly |
| Constellation | Cassiopeia |
| Designations | PN G135.6+01.0, 2MASS J02401437+6109168[1] |
WeBo 1 is a faint ring-shaped planetary nebula discovered in 1996 by astronomers Howard E. Bond and Ronald F. Webbink while they verified the coordinates for the nearby X-ray source LS I +61 303.[2] WeBo 1 sits near the Heart Nebula.
WeBo 1 exhibits characteristics similar to Abell 35-type nuclei. At a distance of 2.2 kpc, its major axis is 0.48 ± 0.26 pc, WeBo 1 has an estimated age of 12,000 ± 6000 yr if 4.7 days is the rotation period.[2]
V1169 Cassiopeiae
[edit]V1169 Cas has the properties of a Barium star or "Ba II star",[3] despite being a K0 III star,[4] V1169 Cas appears red due to interstellar reddening of E(V-I) ≃ 0.77, which corresponds to an E(B-V) ≃ 0.57 or 0.70[5] using the formula from"[6]". Based on an mass of 1.5 M☉, the primary star has a radius of 9 ± 5 R☉.[7] The observed magnitude, reddening, and angular radius[8] imply an upper limit distance of 2.2 to 2.4 kpc and a lower limit distance of 0.75 kpc. The star system maintains a rotation period of 4.7 days, with a visual magnitude of Mv = +1.3 -0.9+1.6 if the distance is 1.6 ± 0.85 kpc.[2]
Although V1169 Cas was thought to be a single star system, a surplus of ultraviolet flux suggests the presence of a companion White dwarf (WD) or Planetary Nebula Nucleus (PNN).[9] This companion is estimated to have a Teff of 40,000 K and a radius less than 0.056 R.[5]
References
[edit]- 1 2 3 "WeBo 1". simbad.cds.unistra.fr.
- 1 2 3 4 Pollacco, L.; Howard, E.; Webbink, F. (2003). "WeBo 1: A Young Barium Star Surrounded by a Ringlike Planetary Nebula". The Astronomical Journal. 125 (1): 260. doi:10.1086/344809.
- ↑ Bidelman, P.; Keenan, C. (November 1951). B/abstract "The Ba II Stars". Astrophysical Journal. 114: 473. Bibcode:1951ApJ...114..473B. doi:10.1086/145488.
{{cite journal}}: Check|url=value (help) - ↑ Bessell, M. S. (October 1979). "UBVRI photometry II: the Cousins VRI system, its temperature and absolute flux calibration, and relevance for two-dimensional photometry". Publications of the Astronomical Society of Japan. 91: 589–607. Bibcode:1979PASP...91..589B. doi:10.1086/130542.
- 1 2 Bond, E.; Siegel, H.; Breeveld, A.; Hoversten, E. A.; Stark, M. (July 2012). "SWIFT/UVOT PHOTOMETRY OF THE PLANETARY NEBULA WeBo 1: UNMASKING A FAINT HOT COMPANION STAR". The Astronomical Journal. 144 (2): 65. doi:10.1088/0004-6256/144/2/65.
- ↑ Warren, P. R.; Dean, J. F.; Cousins, A. W. J. (June 1978). "Reddening of Cepheids using BVI photometry". Monthly Notices of the Royal Astronomical Society. 183: 569–583. Bibcode:1978MNRAS.183..569D. doi:10.1093/mnras/183.4.569.
- ↑ Jorissen, A.; Van Eck, S.; Mayor, M.; Udry, S. (April 1998). "Insights into the formation of barium and Tc-poor S stars from an extended sample of orbital elements". Astronomy & Astrophysics. 332: 877–903. Bibcode:1998A&A...332..877J. doi:10.48550/arXiv.astro-ph/9801272.
- ↑ Marti, J.; Peracaula, M.; Massi, M.; Estalella, R.; Paredes, J. M. (January 1998). "Deep VLA images of LS I +61(deg) 303: a search for associated extended radio emission". Astronomy & Astrophysics. 329: 951–956. Bibcode:1998A&A...329..951M.
- ↑ Schonberner, D. (January 1989). "Evolutionary Tracks for Central Stars of Planetary Nebulae". Proceedings of the International Astronomical Union. 131: 463.
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