Science Archives Publication System

The ¹²C/¹³C Ratio in the Planetary Nebula NGC 3242 from Hubble Space Telescope STIS Observations

DOI: 10.1086/340270 Bibcode: 2002ApJ...568L..57P

Marconi, Alessandro; Tosi, Monica; Stanghellini, Letizia +2 more

We present high-resolution Hubble Space Telescope ultraviolet spectroscopy of NGC 3242, the only planetary nebula with a measured abundance of ³He. The Space Telescope Imaging Spectrograph has been used to observe the C III multiplet near 1908 Å. The presence of ¹²C and ¹³C lines at these wavelengths allows a direc…

2002 • The Astrophysical Journal

eHST 17

Solar cycle variation of the temperature structure within the cores of coronal streamers

DOI: 10.1051/0004-6361:20011563 Bibcode: 2002A&A...381.1049F

Foley, C. R.; Culhane, J. L.; Patsourakos, S. +1 more

We use the Coronal Diagnostic Spectrometer onboard the Solar and Heliospheric Observatory (SOHO) to analyze conditions in coronal streamer structures observed close to solar minimum (1996 July 8) and near maximum (1999 August 5). We measured the intensities of emission lines from Fe IX-XV ions and found the most intense emission to be from Fe XI a…

2002 • Astronomy and Astrophysics

SOHO 17

Henry Draper catalogue identifications for Tycho-2 stars

DOI: 10.1051/0004-6361:20020249 Bibcode: 2002A&A...386..709F

Makarov, V. V.; Fabricius, C.; Wycoff, G. L. +1 more

We present identifications in the Tycho-2 Catalogue, for 99.8 per cent of the stars in the Henry Draper Catalogue and for 96 per cent of the Henry Draper Extensions. Based on observations made with the ESA Hipparcos astrometry satellite. The identifications are available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.7…

2002 • Astronomy and Astrophysics

Hipparcos 17

Characterizing the Adaptive Optics Off-Axis Point-Spread Function. I. A Semiempirical Method for Use in Natural Guide Star Observations

DOI: 10.1086/343217 Bibcode: 2002PASP..114.1267S

Lloyd, J. P.; Graham, James R.; Faber, S. M. +11 more

Even though the technology of adaptive optics (AO) is rapidly maturing, calibration of the resulting images remains a major challenge. The AO point-spread function (PSF) changes quickly in both time and position on the sky. In a typical observation, the star used for guiding will be separated from the scientific target by 10"-30". This is sufficie…

2002 • Publications of the Astronomical Society of the Pacific

eHST 17

HST observations rule out the association between Cir X-1 and SNR G321.9-0.3

DOI: 10.1051/0004-6361:20020224 Bibcode: 2002A&A...386..487M

Caraveo, P. A.; De Luca, A.; Mignani, R. P. +1 more

Cir X-1 is one of the most intriguing galactic X-ray sources. It is a ~16.6 days variable X/radio source, a type-I X-ray burster and a QPO emitter. In spite of an uncertain optical counterpart classification, all these properties identify the source as an LMXB. The morphology of the surrounding radio nebula has suggested an association with the ne…

2002 • Astronomy and Astrophysics

eHST 17

The Photospheric Absorption Lines in the Ultraviolet Spectrum of the Multiple System HD 5980

DOI: 10.1086/344215 Bibcode: 2002ApJ...581..598K

Koenigsberger, Gloria; Kurucz, Robert L.; Georgiev, Leonid

We search for radial velocity variations in the ultraviolet spectra of the erupting Wolf-Rayet/luminous blue variable system HD 5980, located in the Small Magellanic Cloud. We obtain an average radial velocity of 22+/-22 km s^-1 for five observations in 1999 at different orbital phases, -39+/-24 km s^-1 for one observation in 2…

2002 • The Astrophysical Journal

eHST 16

Will Jets Identify the Progenitors of Type Ia Supernovae?

DOI: 10.1086/341413 Bibcode: 2002ApJ...571L..99L

Livio, Mario; Riess, Adam; Sparks, William

We use the fact that a Type Ia supernova has been serendipitously discovered near the jet of the active galaxy 3C 78 to examine the question of whether jets can enhance accretion onto white dwarfs. One interesting outcome of such a jet-induced accretion process is an enhanced rate of novae in the vicinity of jets. We present results of observation…

2002 • The Astrophysical Journal

eHST 16

The white dwarf cooling sequence in the old open cluster NGC 188

DOI: 10.1051/0004-6361:20020858 Bibcode: 2002A&A...390..961A

Andreuzzi, G.; Richer, H. B.; Limongi, M. +1 more

We develop the white dwarf luminosity function (LF) of the old open cluster NGC 188 in order to determine a lower limit to the age of the cluster by using the faint end of the cooling sequence. To produce an extensive sequence of the cooling white dwarfs we imaged four contiguous HST-WFPC2 fields in the center of the cluster in the F555W and F814W…

2002 • Astronomy and Astrophysics

eHST 16

The massive double-lined O-type binary HD 165052

DOI: 10.1046/j.1365-8711.2002.05404.x Bibcode: 2002MNRAS.333..202A

Barbá, R. H.; Morrell, N. I.; Arias, J. I. +3 more

We present a new optical spectroscopic study of the O-type binary HD 165052 based on high- and intermediate-resolution CCD observations. We re-investigated the spectral classification of the binary components, obtaining spectral types of O6.5V and O7.5V for the primary and secondary, respectively, finding that both stars display weak CIIIλ5696 emi…

2002 • Monthly Notices of the Royal Astronomical Society

IUE 16

The Central Binary and Surrounding Nebula of the Symbiotic Star V1016 Cygni

DOI: 10.1086/340018 Bibcode: 2002ApJ...571..947B

Eyres, S. P. S.; Bode, M. F.; Taylor, A. R. +3 more

We present Hubble Space Telescope (HST) Wide Field Planetary Camera 2 images of the symbiotic star V1016 Cygni that, for the first time, directly explore the inner regions of the nebula to AU scales at optical wavelengths. They also suggest that the [O III] λλ4959, 5007 emission takes place in a bipolar outflow. We use these images to determine th…

2002 • The Astrophysical Journal

eHST 16