High-dispersion observations of H-alpha in the suspected brown dwarf, white dwarf binary system G29-38
نویسندگان
چکیده
منابع مشابه
Keck Speckle Imaging of the White Dwarf G29-38: No Brown Dwarf Companion Detected
The white dwarf Giclas 29-38 has attracted much attention due to its large infrared excess and the suggestion that excess might be due to a companion brown dwarf. We observed this object using speckle interferometry at the Keck telescope, obtaining diffraction-limited resolution (55 milliarcseconds) at K band, and found it unresolved. Assuming the entire K band excess is due to a single point-l...
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A near-infrared excess is detected at the white dwarf PHL 5038 in UKIDSS photometry, consistent with the presence of a cool, substellar companion. We have obtained Hand K-grism spectra and images of PHL 5038 using NIRI on Gemini North. The target is spatially and spectrally resolved into two components; an 8000 K DA white dwarf, and a likely L8 brown dwarf companion, separated by 0.94 ′′. The s...
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Metals in the photospheres of white dwarfs with TeA between 12,000 and 25,000 K should gravitationally settle out of these atmospheres in 1Y2 weeks. Temporal variations in the line strengths of these metals could provide a direct measurement of episodic metal accretion. Using archival VLTand Keck spectroscopy, we find evidence that the DAZd white dwarf G29-38 shows significant changes in its Ca...
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Optical time series photometry of the short period magnetic white dwarf + probable brown dwarf binary SDSS J121209.31 + 013627.7 reveals pulse-like variability in all bands from i to u, increasing towards bluer wavelengths and peaking at u. These modulations are most likely due to a self-eclipsing accretion hot spot on the white dwarf, rotating into view every 88.43 minutes. This period is comm...
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ژورنال
عنوان ژورنال: The Astronomical Journal
سال: 1989
ISSN: 0004-6256
DOI: 10.1086/114967