Search Publications

Far infrared spectroscopy of FU Ori objects. ISO-LWS observations
Bibcode: 2000A&A...357.1035L

Liseau, R.; White, G. J.; Benedettini, M. +12 more

We present the results of the first spectrophotometric observations of a sample of FU Ori objects obtained with the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). The [OI] (63 mu m) and the [CII] (158 mu m) lines are commonly observed in all spectra (both ON and OFF source). The observational novelty is the prese…

2000 Astronomy and Astrophysics
ISO 21
Mechanisms for dynamic coronal mass supply via evaporative solar ``micro-events''
Bibcode: 2000A&A...359.1185B

Güdel, M.; Krucker, S.; Benz, A. O. +1 more

The idea that the corona is at least in part supplied by chromospheric evaporation in loop ``micro-events" is quantified in terms of the power requirements of evaporation mechanisms, using recent analyses of data on such events in high temperature EUV lines from the SoHO EIT instrument. Estimates are derived for the pre-event and event values of l…

2000 Astronomy and Astrophysics
SOHO 21
The ISO spectroscopic view of the HH 24-26 region
Bibcode: 2000A&A...359..148B

White, G. J.; Benedettini, M.; Lorenzetti, D. +6 more

We report the results of an investigation, performed with the ISO spectrometers (LWS and SWS), on the star forming region associated with the Herbig-Haro objects HH 24-25 and 26. Low-resolution LWS spectra (45-197 mu m) were observed towards the HH24MMS, HH25MMS and HH26IR sources as well as the HH26IR outflow. In addition, SWS scans of the pure H…

2000 Astronomy and Astrophysics
ISO 21
Characteristics of quiet Sun cell and network brightenings
Bibcode: 2000A&A...362..371H

Phillips, K. J. H.; Harra, L. K.; Gallagher, P. T.

Extreme ultraviolet observations of the quiet Sun are made with the Coronal Diagnostic Spectrometer (cds) on board the Solar and Heliospheric Observatory (soho). It has been previously noted that frequent transition region brightenings occur in both the bright network and dark cell regions. Analysing 1125 events, we determined the characteristics …

2000 Astronomy and Astrophysics
SOHO 21
ISO observations of a sample of 60 mu m peaker galaxies
DOI: 10.48550/arXiv.astro-ph/0005076 Bibcode: 2000A&A...359..900L

Hanlon, L.; McBreen, B.; Clavel, J. +9 more

The sample of IRAS galaxies with spectral energy distributions that peak near 60 mu m are called Sixty Micron Peakers (SMPs or 60PKs). Their generally peculiar and amorphous morphologies, hot dust and lack of a cirrus component have been interpreted as being indicative of a recent interaction/merger event. Mid-infrared spectra of eight SMPs, obtai…

2000 Astronomy and Astrophysics
ISO 21
Polaris: astrometric orbit, position, and proper motion
DOI: 10.48550/arXiv.astro-ph/0002406 Bibcode: 2000A&A...360..399W

Wielen, R.; Dettbarn, C.; Jahreiß, H. +2 more

We derive the astrometric orbit of the photo- center of the close pair α UMi AP (= α UMi Aa) of the Polaris multiple stellar system. The orbit is based on the spectroscopic orbit of the Cepheid α UMi A (orbital period of AP: 29.59 years), and on the difference Δµ between the quasi-instantaneously measured HIPPARCOS proper motion of Polaris a…

2000 Astronomy and Astrophysics
Hipparcos 21
HV Ursae Majoris, a new contact binary with early-type components
DOI: 10.48550/arXiv.astro-ph/0002379 Bibcode: 2000A&A...356..603C

Kiss, L. L.; Alfaro, E. J.; Csák, B. +1 more

We present the first UBV and uvby photometric observations for the short period variable star HV Ursae Majoris classified as a field RRc variable. The observed differences between the consecutive minima and the lack of colour variations disagree with the RRc-classification and suggest the possible binary nature of HV UMa. In order to reveal the re…

2000 Astronomy and Astrophysics
Hipparcos 20
Multi-wavelength observations and modelling of shock-cloud interaction regions in the Vela Supernova Remnant
Bibcode: 2000A&A...359..316B

Bocchino, F.; Sciortino, S.; Raymond, J. +1 more

We present optical photometric and spectrophotometric observations of two selected filaments near the North rim of the Vela supernova remnant also observed in UV with the International Ultraviolet Explorer, and in X-rays with the ROSAT PSPC detector. From the optical data, we have derived spatially-resolved ( ~ 3'') profiles of several …

2000 Astronomy and Astrophysics
IUE 20
VLBI observations of two single dMe stars: spatial resolution and astrometry
DOI: 10.48550/arXiv.astro-ph/9912159 Bibcode: 2000A&A...353..569P

Güdel, M.; Benz, A. O.; Conway, J. E. +1 more

We report on 3.6 cm VLA and VLBA observations of YZ CMi and AD Leo, two nearby dMe stars. We resolve YZ CMi and can fit a circular symmetrical gaussian component of FWHP of 0.98 +/-0.2 mas, corresponding to an extent of the corona above the photosphere of 1.77 x 1010 +/-8.8 x 109 cm or 0.…

2000 Astronomy and Astrophysics
Hipparcos 20
HST spectroscopy of the double QSO HS 1216+5032 AB
DOI: 10.48550/arXiv.astro-ph/0003427 Bibcode: 2000A&A...357...37L

Reimers, D.; Hagen, H. -J.; Lopez, S.

We report on Hubble Space Telescope Faint Object Spectrograph observations of the double QSO HS 1216+5032 AB (z_e(A)=1.455; z_e(B)=1.451, and angular separation theta =9.1farcs ). The spectral coverage is 910 Å to 1340 Å in the QSO rest-frame. An unusual broad-absorption-line (BAL) system is observed only in the B component: maximum outflow veloci…

2000 Astronomy and Astrophysics
eHST 20