The pulsating nucleus of the planetary nebula Longmore 4

Journal Article · Sat Sep 01 00:00:00 EDT 1990 · Astronomical Journal; (USA)

DOI:https://doi.org/10.1086/115560· OSTI ID:6483052

Bond, H E; Meakes, M G ^[1]

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1. Space Telescope Science Institute, Baltimore, MD (USA)

CCD photometry of the planetary nebula Longmore 4 is presented to show that the central star of the nebula is a multiperiodic pulsator. Both its spectrum, which is dominated by features of He II and C IV, and its pulsation periods are very similar to those of the other known pulsating central star, K 1-16. The four known pulsating GW Vir white dwarfs are also dominated by features of He II, C IV, and O IV, indicating extremely hot (100,000 K or higher), hydrogen-deficient, and carbon- and oxygen-rich surface layers. The apparent uniformity of the chemical compositions supports a pulsation mechanism based on cyclical ionization of carbon and oxygen. 31 refs.

• OSTI ID: 6483052
• Journal Information: Astronomical Journal; (USA), Vol. 100; ISSN 0004-6256
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
PLANETARY NEBULAE
PHOTOMETRY
WHITE DWARF STARS
OSCILLATIONS
CHARGE-COUPLED DEVICES
CHEMICAL COMPOSITION
SPECTROPHOTOMETRY
STAR EVOLUTION
VARIABLE STARS
DWARF STARS
NEBULAE
SEMICONDUCTOR DEVICES
STARS
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources