MWP 1
| Emission nebula | |
|---|---|
| Planetary nebula | |
 Image of MWP 1 from the mosaic camera on the Nicholas U. Mayall Telescope at Kitt Peak | |
| Observation data: J2000 epoch | |
| Right ascension | 21h 16m 30s[1] |
| Declination | +34° 11′ 42″[1] |
| Distance | (~503 pc) ~1,637[2] ly |
| Constellation | Cygnus |
| Designations | PK 080-10 1, PN G080.3-10.4, PN G080.8-10.6, RX J2117.1+3412[1] |
MWP 1 or the Methuselah nebula is a large planetary nebula surrounding the X-ray source RX J2117.1+3412. MWP 1 was first noticed in 1987 by Alain Maury at the Palomar Schmidt telescope. In 1992 astronomers Motch, Werner, and Pakull (MWP) identified the X-ray source RX J2117.1+3412 and in the same year Appleton, Kawaler, and Eitter discovered a large planetary nebula surrounding RX J2117.1+3412.[3]
MWP 1 shows a bright inner region and an extensive bipolar shape containing filaments and arcs. The shape of the outer emission is a very faint "S-shape". The position angle of the major axis for larger structure is 50° north through east.[3] The maximum extent of MWP 1 is 13 arcmin proving the linear diameter of the nebula is 5.3 pc. The filaments of MWP 1 are similar to He 2-104, which could help explain the origin of the filaments.[4]
MWP has an expansion age of about 10⁵ yr, based on an expansion velocity of 20 km/s.[5]
The inner regions of MWP 1 have a typical surface brightness of 1.5x10-15 ergs cm⁻² s⁻² arcsec⁻² for Hα and 1.2x10-16 ergs cm⁻² s⁻² arcsec⁻² for O III, while the hook feature to the south has a surface brightness 1.7 times brighter than Hα and 2.1 times brighter than O III, and the average brightness in the filaments is 9.4x10-17 ergs cm⁻² s⁻² arcsec⁻² for O III and approximately 5.1x10-17 ergs cm⁻² s⁻² arcsec⁻² for the Hα line.[3]
RX J2117.1+3412
[edit]X-ray source and central star RX J2117.1+3412 lies at the "knee" of the evolutionary track where the star reaches maximum effective temperature and enters the white dwarf cooling sequence. The star has an age fewer than 10⁴ yr, assuming it is a helium-burning star with a mass of 0.60 M☉.[3] Recent observations of RX J2117.1+3412 show that the star pulsates between 600 s and 1000 s. RX J2117.1+3412 is a PG 1159 star,[6] a classification that was proven by the discovery of this nebula. The star has a surface temperature of ~150,000 K[7]
References
[edit]- 1 2 3 "MWP 1". simbad.cds.unistra.fr.
- ↑ Mindil, A.; Algarni, E.; Alghamdi, S. A.; Ali, A. (June 2022). "A new statistical distance scale for planetary nebulae, based on Gaia EDR3". p. 13. doi:10.1088/1674-4527/ac7545.
- 1 2 3 4 Eitter, J. J.; Appleton, P. N.; Kawaler, S. D. (November 1993). "An Enormous Planetary Nebula Surrounding the X-Ray Source RXJ 2117+34". The Astronomical Journal. 106 (5): 1973–1979. Bibcode:1993AJ....106.1973A. doi:10.1086/116778.
- ↑ Lutz, J. H.; Kaler, J. B.; Schwarz, H. E.; Aspin, C.; Shaw, R. A. (1989). "HE 2-104: A LINK BETWEEN SYMBIOTIC STARS AND PLANETARY NEBULAE". The Astronomical Society of the Pacific. 101 (645): 966. doi:10.1086/132560.
- ↑ Osterbrock, D. E. (1989). Astrophysics of gaseous nebulae and active galactic nuclei. University Science Books. p. 408. ISBN 0-935702-22-9.
- ↑ Werner, K.; Pakull, M. W.; Motch, C. (February 1993). "A new PG 1159 star discovered in the ROSAT XRT all sky survey : NLTE analysis of X-ray and optical spectra". Astronomy & Astrophysics. 268: 561–569. Bibcode:1993A&A...268..561M.
- ↑ Pakull, M. W.; Werner, K.; Motch, C.; Dolez, N.; Chevreton, M.; Pfeiffer, B.; Belmonte, J. A.; Vauclair, G. (1993). "A new pulsating PG 1159 star dwarf: RXJ 2117.1+3412". Astronomy & Astrophysics: L35–L38. ISSN 0004-6361.