Elemental compositions of two extrasolar rocky planetesimals

Journal Article · Mon Mar 10 00:00:00 EDT 2014 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/783/2/79· OSTI ID:22351608

Xu, S.; Jura, M.; Klein, B.; Zuckerman, B. ^[1]

---

1. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1562 (United States)

We report Keck/HIRES and Hubble Space Telescope/COS spectroscopic studies of extrasolar rocky planetesimals accreted onto two hydrogen atmosphere white dwarfs, G29-38 and GD 133. In G29-38, eight elements are detected, including C, O, Mg, Si, Ca, Ti, Cr, and Fe while in GD 133, O, Si, Ca, and marginally Mg are seen. These two extrasolar planetesimals show a pattern of refractory enhancement and volatile depletion. For G29-38, the observed composition can be best interpreted as a blend of a chondritic object with some refractory-rich material, a result from post-nebular processing. Water is very depleted in the parent body accreted onto G29-38, based on the derived oxygen abundance. The inferred total mass accretion rate in GD 133 is the lowest of all known dusty white dwarfs, possibly due to non-steady state accretion. We continue to find that a variety of extrasolar planetesimals all resemble to zeroth order the elemental composition of bulk Earth.

• OSTI ID: 22351608
• Journal Information: Astrophysical Journal, Vol. 783, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABUNDANCE
ELEMENT ABUNDANCE
HYDROGEN
MASS
OXYGEN
REFRACTORIES
SPACE
STEADY-STATE CONDITIONS
TELESCOPES
WHITE DWARF STARS