High-speed knots in the hourglass shaped planetary nebula Hubble 12

Abstract

We present a detailed kinematical analysis of the young compact hourglass-shaped planetary nebula Hb 12. We performed optical imaging and longslit spectroscopy of Hb 12 using the Manchester echelle spectrometer with the 2.1m San Pedro Martir telescope. We reveal, for the first time, the presence of end caps (or knots) aligned with the bipolar lobes of the planetary nebula shell in a deep [NII]6584 image of Hb 12. We measured from our spectroscopy radial velocities of 120 km/s for these knots. We have derived the inclination angle of the hourglass shaped nebular shell to be 65 degrees to the line of sight. It has been suggested that Hb 12's central star system is an eclipsing binary (Hsia et al. 2006) which would imply a binary inclination of at least 80 degrees. However, if the central binary has been the major shaping influence on the nebula then both nebula and binary would be expected to share a common inclination angle. Finally, we report the discovery of high-velocity knots with Hubble-type velocities, close to the core of Hb 12, observed in Halpha and oriented in the same direction as the end caps. Very different velocities and kinematical ages were calculated for the outer and inner knots showing that they may originate from different outburst events.

9 pages, 6 figures, accepted for publication in MNRAS

References in corpus (12)

• The Origin and Shaping of Planetary Nebulae: Putting the Binary Hypothesis to the Test
• Binary Planetary Nebulae Nuclei towards the Galactic Bulge. I. Sample Discovery, Period Distribution and Binary Fraction
• A magnetically collimated jet from an evolved star
• Do most planetary nebulae derive from binaries? I Population synthesis model of the galactic planetary nebula population produced by singlestars and binaries
• Isolated vs. Common Envelope Dynamos in Planetary Nebula Progenitors
• Binary central stars of PN discovered through photometric variability. I. What we know and what we would like to find out
• A planetary nebula around nova V458 Vul undergoing flash ionization
• Magnetic fields in planetary nebulae and post-AGB nebulae
• Proof of polar ejection fom the close-binary core of the planetary nebula Abell 63
• Hubble-type outflows of the high-excitation, poly-polar planetary nebula NGC 6302 -- from expansion proper motions
• The magnetic field toward the young planetary nebula K~3-35
• The Evidence for a Binary origin of the Young Planetary Nebula HB 12

Cited by in corpus (13)

• Planetary Nebulae: Observational Properties, Mimics, and Diagnostics
• The Necklace: equatorial and polar outflows from the binary central star of the new planetary nebula IPHASXJ194359.5+170901
• ETHOS 1: A high latitude planetary nebula with jets forged by a post common envelope binary central star
• SALT HRS discovery of the binary nucleus of the Etched Hourglass Nebula MyCn 18
• Extended Structures of Planetary Nebulae Detected in H${}_2$ Emission
• High velocity string of knots in the outburst of the Planetary Nebula Hb4
• Multiple outflows in the planetary nebula NGC 6058
• Distance mapping applied to four well-known planetary nebulae and a nova shell
• Two-wind interactions in binaries with two orbiting giant stars
• Spectroscopic Variability of the Compact Planetary Nebula Hb 12
• Morphological study of the nested planetary nebula Hubble 12
• Fallback in bipolar Planetary Nebulae ?
• [Fe II] 1.644$\mu$m imaging survey of planetary nebulae with low-ionisation structures