Search Publications

BI Lyncis: A hydrogen-deficient binary consisting of two low-mass giants of spectral types early-B and G
DOI: 10.1051/0004-6361:20011255 Bibcode: 2001A&A...378..936J

Jeffery, C. S.; Aznar Cuadrado, R.

BI Lyn has previously been misclassified as an evolved binary system containing either a hot subdwarf or white dwarf and a thick accretion disk. New intermediate dispersion spectra are presented which demonstrate clearly that the hot component is a luminous low-mass helium star and the cool companion is a rapidly rotating G-type…

2001 Astronomy and Astrophysics
IUE 7
New physical elements of HR 7428 and its Hα behaviour.
DOI: 10.1051/0004-6361:20010823 Bibcode: 2001A&A...375..100M

Frasca, A.; Catalano, S.; Marilli, E. +1 more

HR 7428 is a spectroscopic binary composed of a K2 II-III and a main-sequence A2 star. Thanks to a new set of radial velocity measurements from our and IUE spectroscopy we have improved the orbital period determination and the spectroscopic elements of both components. Combining optical photometry and UV low dispersion IUE spect…

2001 Astronomy and Astrophysics
IUE 7
Evidence for prolonged main sequence stellar evolution of F stars in close binaries
DOI: 10.1051/0004-6361:20010148 Bibcode: 2001A&A...369..554S

Suchkov, A. A.

Binary F stars exhibit large brightness anomaly, which is defined here as the difference between the absolute magnitude from the \mboxuvby photometry and the actual absolute magnitude of the star. We have found that the anomaly inversely correlates with the binary components separation. There is evidence that the correlation reflects actual popula…

2001 Astronomy and Astrophysics
Hipparcos 6
The late-time expansion of the ejecta of SN 1987A
DOI: 10.1051/0004-6361:20010292 Bibcode: 2001A&A...370.1056J

Jakobsen, P.; Jansen, R. A.

The evolution of the shape and size of the ejecta of SN 1987A is analyzed over a period of ~ 8 years based on HST images and spectra taken between 1278 and 4336 days after the supernova outburst. We combine both proprietary and archival HST data obtained with the FOC, WFPC2 and STIS. The low resolution near-UV prism FOC spectrum obtained at day 30…

2001 Astronomy and Astrophysics
eHST 6
Contribution to the search of binaries among Am stars. II. HD 81976 and HD 98880, double-lined spectroscopic binaries
DOI: 10.1051/0004-6361:20010168 Bibcode: 2001A&A...369..908C

Ginestet, N.; Prieur, J. -L.; Carquillat, J. -M.

We present the results of the observations of two Am stars of eighth magnitude, the double-lined spectroscopic binaries HD 81976 and HD 98880, carried out with the CORAVEL instrument at the Observatoire de Haute-Provence in order to determine their orbital elements. We found 1) for HD 81976: P = 5.655750 days, T = 2449785.941 HJD, omega = 341.4

2001 Astronomy and Astrophysics
Hipparcos 6
ROSAT/Chandra observations of a bright transient in M 81
DOI: 10.1051/0004-6361:20011396 Bibcode: 2001A&A...380..251G

Tennant, A. F.; Wu, K.; Swartz, D. A. +1 more

We present a 10-year X-ray light curve and the spectra of a peculiar X-ray transient in the spiral galaxy M 81. The source was below the detection limit of ROSAT PSPC before 1993, but it brightened substantially in 1993, with luminosities exceeding the Eddington limit of a 1.5-M_sun compact accretor. It then faded and was not firmly detected in th…

2001 Astronomy and Astrophysics
eHST 6
Temporal and spatial variations of the quiet upper chromosphere from SOHO/SUMER observations of hydrogen Lyman lines
DOI: 10.1051/0004-6361:20010755 Bibcode: 2001A&A...374..691K

Kariyappa, R.; Curdt, W.; Varghese, B. A.

We have analyzed a time series of spectra in the hydrogen Lyman lines and the Lyman continuum obtained by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on the SOlar Heliospheric Observatory (SOHO). The time series of about 2 hours and 22 min was obtained on 1999 March 9 in a quiet region near the center of the solar …

2001 Astronomy and Astrophysics
SOHO 5
Search for the [C{{II}}] 158 micron emission toward the blue compact dwarf galaxy I Zw 36
DOI: 10.1051/0004-6361:20010281 Bibcode: 2001A&A...370..868M

Onaka, T.; Mochizuki, K.

We observed the blue compact dwarf galaxy I Zw 36 in the [C Ii] 158 mu m line with the Infrared Space Observatory obtaining an upper limit for the line flux, F_[ion {C{ii}]} <= 1.1 10-20 W cm-2 (3 sigma ). A comparison with previous CO observations yields an upper limit for the [C Ii]/CO J = 1-0 line flux ratio, F_[ion {C{…

2001 Astronomy and Astrophysics
ISO 5
ISO continuum observations of quasars at z=1-4. I. Spectral energy distributions of quasars from the UV to far-infrared
DOI: 10.1051/0004-6361:20000508 Bibcode: 2001A&A...365..409O

Kawara, K.; Taniguchi, Y.; Oyabu, S. +8 more

Eight luminous quasars with -30 < MB < -27 at z = 1.4-3.7 have been observed in the mid- and far-infrared using ISO. All the quasars have been detected in the mid-infrared bands of ISOCAM, while no far-infrared detections have been made with ISOPHOT. SEDs (Spectral Energy Distributions) from the UV to far-infrared have been obtain…

2001 Astronomy and Astrophysics
ISO 5
The brightness of SN 1991T and the uniformity of decline-rate and colour corrected absolute magnitudes of supernovae Ia
DOI: 10.1051/0004-6361:20000104 Bibcode: 2001A&A...368..391R

Tonry, J.; Richtler, T.; Jensen, J. B. +2 more

We present a distance to NGC 4527, the host galaxy of the type Ia SN 1991T, measured by surface brightness fluctuations. This supernova has been labelled ``peculiar'' both on the grounds of its spectroscopic behaviour and its apparent overluminosity with respect to other supernovae. The distance modulus to

2001 Astronomy and Astrophysics
eHST 5