Hubble 5

Hb 5
Emission nebula
Planetary nebula
Image of Hb 5 from the Hubble Space Telescope
Observation data: J2000 epoch
Right ascension17h 47m 56.25s
Declination−29° 59′ 40.07″
Apparent diameter52" x 18"
ConstellationSagittarius
DesignationsPK 359.3-00.1, Hen 2-286, PN G359-3.3-00.9, Sa 2-244, BI 1-E
See also: Lists of nebulae

Hubble 5 (Hb 5) is a large bipolar planetary nebula (PN) with a complex shape. The nebula was discovered by American astronomer Edwin Hubble in 1921.

The nebula is a bipolar, point-symmetric PN with complex shapes. Hb 5 has an estimated size of 52" x 18" in Hα. The distance of Hb 5 remains uncertain, with estimates ranging between 0.7 kpc and 2 kpc. The electron temperature of the nebula is 13,000K-16,000K based on the Ne III temperature being lower than the Ne V temperature. The Hβ flux is ~3.0 x 10-12 erg cm⁻² s⁻¹ or 1.19 x 10-10 erg cm⁻² s⁻¹.

Central star

Central star is very faint and has an Ne VI line that proves that the star is quite hot. The star has a zanstra temperature ranging from ~100,000 K for hydrogen to ~130,000 K for helium II. The star has a radius of about ~0.17 R☉ and a luminosity of 2 x 10⁴ Lʘ.

References

  1. 1 2 3 "PN Hb 5". simbad.cds.unistra.fr.
  2. 1 2 3 Pottasch, S. R.; Surendiranath, R. (2007). "Abundances in planetary nebulae: Hb 5" (PDF). Astronomy & Astrophysics. 462: 179–192. doi:10.1051/0004-6361:20066012.
  3. ↑ 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.
  4. ↑ Corradi, L. M.; Schwarz, H. E. (1993). "Kinematics of bipolar planetary nebulae". Astronomy & Astrophysics. 278: 247–254.
  5. ↑ Acker, A.; Ochsenbein, F.; Stenholm, B. (1992). "The Strasbourg-ESO Catalogue of Galactic Planetary Nebulae. Parts I, II". European Southern Observatory. Bibcode:1992secg.book.....A.
  6. ↑ Odell, C. R. (1963). "Photoelectric Spectrophotometry of Gaseous Nebulae. I. The [S ii] Lines". The Astrophysical Journal. 138: 1018.