Search Publications
Faint stars in the Ursa Minor dwarf spheroidal galaxy: implications for the low-mass stellar initial mass function at high redshift
Wyse, Rosemary F. G.; Gilmore, Gerard; Gallagher, John S., III +4 more
The stellar initial mass function at high redshift is an important defining property of the first stellar systems to form and may also play a role in various dark matter problems. We here determine the faint stellar luminosity function in an apparently dark-matter-dominated external galaxy in which the stars formed at high redshift. The Ursa Minor…
XMM-Newton observations of the nearby brown dwarf LP 944-20
Bouy, Hervé; Martín, Eduardo L.
The nearby ( d=5.0 pc) brown dwarf LP 944-20 was observed with the XMM-Newton satellite on 07 January 2001. The target was detected with the Optical Monitor ( V=16.736±0.081), but it was not detected during the ≈48 ks observation with the X-ray telescopes. We determine a 3 σ upper limit for the X-ray emission from this object of LX<3…
Observations of Mira stars with the IOTA/FLUOR interferometer and comparison with Mira star models
Beckmann, U.; Weigelt, G.; Hofmann, K. -H. +16 more
We present K'-band observations of five Mira stars with the IOTA interferometer. The interferograms were obtained with the FLUOR fiber optics beam combiner, which provides high-accuracy visibility measurements in spite of time-variable atmospheric conditions. For the M-type Miras X Oph, R Aql, RU Her, R Ser, and the C-type Mira V CrB we derived th…
Diagnosis of coronal magnetic field with data of Nobeyama Radio Heliograph
Nakajima, Hiroshi; Huang, Guang-Li
The expression is derived for the coronal magnetic field strength from the observations of brightness, temperature, peak frequency, spectral index, and polarization degree of solar microwave bursts. One example of solar burst on November 28, 1998 is given for the calculation of coronal magnetic field from the data of Nobeyama Radio Heliograph (NoR…
The relation between far-UV and visible extinctions
Zagury, Frederic
For directions of sufficient reddening ( E( B- V)>∼0.25), there is a simple relation between the slope of the extinction curve in the far-UV and E( B- V). Regardless of direction, the far-UV extinction curve is proportional to 1/ λn e -2 E( B- V)/ λ ( λ in µm, n=4), in accordance with the idea that reddened stars spe…