Science Archives Publication System

The HIPPARCOS mission: photometric data.

Bibcode: 1997A&A...323L..61V

Evans, D. W.; Mignard, F.; van Leeuwen, F. +3 more

An overview of the Hipparcos and Tycho photometric data is presented, with reference to the main aspects of the data reductions and the overall quality and quantity of the results. The data have been presented in three forms: as mean values in the astrometric catalogues, as epoch photometry, and as interpreted results of the variability analysis, …

1997 • Astronomy and Astrophysics

Hipparcos 102

Interstellar Abundances in the Magellanic Clouds. I. GHRS Observations of the Small Magellanic Cloud Star Sk 108

DOI: 10.1086/304811 Bibcode: 1997ApJ...489..672W

York, D. G.; Blades, J. C.; Welty, D. E. +2 more

We present HST GHRS echelle-B and G160M spectra of the Wolf-Rayet binary Sk 108, located in the northeastern part of the main ``bar'' of the Small Magellanic Cloud. The spectra show interstellar absorption from C I, O I, Si II, Si II*, S II, P II, Cr II, Mn II, Fe II, Ni II, and Zn II. We find at least 25 interstellar components, which may be grou…

1997 • The Astrophysical Journal

eHST 101

The activity and size of the nucleus of Comet Hale-Bopp (C/1995 O1)

DOI: 10.1126/science.275.5308.1900 Bibcode: 1997Sci...275.1900W

Feldman, P. D.; A'Hearn, M. F.; Weaver, H. A. +1 more

1997 • Science

eHST 101

Models for Dense Molecular Cloud Cores

DOI: 10.1086/304764 Bibcode: 1997ApJ...489..122D

Neufeld, David A.; Doty, Steven D.

We present a detailed theoretical model for the thermal balance, chemistry, and radiative transfer within quiescent dense molecular cloud cores that contain a central protostar. In the interior of such cores, we expect the dust and gas temperatures to be well coupled, while in the outer regions CO rotational emissions dominate the gas cooling and …

1997 • The Astrophysical Journal

ISO 101

Determination of the Sun's Seismic Radius from the SOHO Michelson Doppler Imager

DOI: 10.1086/316782 Bibcode: 1997ApJ...489L.197S

Kosovichev, A. G.; Schou, J.; Dziembowski, W. A. +1 more

Dopplergrams from the Michelson Doppler Imager (MDI) instrument on board the SOHO spacecraft have been used to accurately measure frequencies of the Sun's fundamental (f) mode in the medium angular degree range, l = 88--250. The comparison of these frequencies with the corresponding frequencies of the standard solar models suggests that the appare…

1997 • The Astrophysical Journal

SOHO 100

Discovery of Far-Infrared Pure Rotational Transitions of CH⁺ in NGC 7027

DOI: 10.1086/310729 Bibcode: 1997ApJ...483L..65C

Barlow, M. J.; Cernicharo, J.; González-Alfonso, E. +4 more

We report the discovery of the rotational spectrum of CH⁺ in the Infrared Space Observatory Long Wavelength Spectrometer (LWS) spectrum of the planetary nebula NGC 7027. The identification relies on a 1996 reanalysis of the LWS spectrum by Liu et al. and on new LWS data. The strong line at 179.62 µm (coinciding with the 2₁₂

1997 • The Astrophysical Journal

ISO 98

WFPC2 Observations of the Carina Dwarf Spheroidal Galaxy.

DOI: 10.1086/118576 Bibcode: 1997AJ....114.1458M

Mighell, Kenneth J.

We present our analysis of Hubble Space Telescope Wide Field Planetary Camera 2 observations in F555W (∼V) and F814W (∼I) of the Carina dwarf spheroidal galaxy. The resulting V vs V-I color-magnitude diagrams reach V≈27.1 mag. The reddening of Carina is estimated to be E(V-I)=0.08±0.02 mag. A new estimate of the distance modulus of Carina, (m - M)…

1997 • The Astronomical Journal

eHST 98

The Asymmetric Radio Remnant of SN 1987A

DOI: 10.1086/303917 Bibcode: 1997ApJ...479..845G

Gaensler, B. M.; Manchester, R. N.; Staveley-Smith, L. +3 more

We present seven years of radio observations of SN 1987A made with the Australia Telescope Compact Array. At 1.4, 2.4, 4.8, and 8.6 GHz, the flux density of the radio remnant has increased monotonically since emission was redetected 1200 days after the explosion. On day 3200, the remnant was expanding at 2800 +/- 400 km s^-1, which we in…

1997 • The Astrophysical Journal

eHST 98

HST/GHRS Observations of the Compact Slow Ejecta of Eta Carinae

DOI: 10.1086/118256 Bibcode: 1997AJ....113..335D

Humphreys, R. M.; Balick, B.; Davidson, Kris +6 more

We report spectroscopic observations of eta Car and adjacent gas with an unprecedented combination of spatial and spectral resolution, 0.1 arcsec x 0.1 Angstroms. Radial velocities show that the bright objects C and D, 0.2 arcsec from the star, are slow equatorial ejecta. The narrow emission lines which fluctuate in the spectrum of the core region…

1997 • The Astronomical Journal

eHST 97

Globular cluster orbits based on Hipparcos proper motions

DOI: 10.1016/S1384-1076(97)00035-3 Bibcode: 1997NewA....2..477O

Tucholke, H. -J.; Brosche, P.; Odenkirchen, M. +1 more

We present and analyse space motions and orbits for a sample of 15 galactic globular clusters. The absolute proper motions of these clusters have been determined with respect to reference stars of the new Hipparcos system. Orbital integrations in two model potentials for the Galaxy are considered.

The sample shows a mean rotation near 40 km s…

1997 • New Astronomy

Hipparcos 95