%R 1997PASP..109...73G
%J-77
%T Subrahmanyan Chandrasekhar (1910-1995)
%A GARSTANG R.H.
%F contents_97_02
%K Obituaries
%B With the passing of Chandrasekhar the astronomical community lost its most productive theoretical astrophysicist. His
work covered stellar structure and white dwarf stars, stellar dynamics, the absorption coefficient of the negative
hydrogen ion, radiative transfer, hydrodynamic and hydromagnetic stability, ellipsoidal figures of equilibrium, and
black holes. I point out some highlights of his work, and add some notes based mainly on my personal experiences at
Yerkes Observatory.

%R 1997PASP..109...78T
%J-113
%T Astrophysics in 1996
%A TRIMBLE VIRGINIA, MCFADDEN LUCY ANN
%F contents_97_02
%K Invited Review Paper
%B The loudest astronomical headlines of the year came from both very near (planets orbiting stars in the solar
neighborhood) and very far (galaxies and parts of galaxies at redshifts of 1 to 3 and more). We explore these and other
happenings in our Solar System (Galileo at Jupiter, Comet Hyakutake), Milky Way (the bursting pulsar, spotted stars),
Local Group (masers, MACHOs, and more), and Universe (gravitational lensing, an assortment of extrema).

%R 1997PASP..109..114S
%J-124
%T Superhumps in Cataclysmic Binaries. X. V1974 Cygni (Nova Cygni 1992)
%A SKILLMAN DAVID R., HARVEY DAVID, PATTERSON JOSEPH, VANMUNSTER TONNY
%F contents_97_02
%K Stars
%B We report photometry of V1974 Cygni, the remnant of Nova Cygni 1992. A very nearly stable photometric signal with a
period of 117.012 (\pm.002) min was present throughout 1993-6, with declining amplitude. This appears to be the
underlying orbital period of the binary; at least during 1993, it probably manifested itself through the external
heating of the secondary star's atmosphere. We interpret the declining signal amplitude as the result of white dwarf
cooling after the nova ouburst. This suggests an e-folding timescale of \sim 80 d for luminosity decline, consistent
with the UV flux which probably arises from the heated accretion disk. During 1994-1996 there appeared another
photometric signal, far less stable. The period varied in the range 122.4-122.7 min, with an average {dot}P \mid
of about 10^6^. We interpret this as a "superhump," a common phenomenon in cataclysmic binaries of short P_orb_ and
high accretion rate.

%R 1997PASP..109..125M
%J-129
%T The Star-Formation History of LGS 3
%A MOULD JEREMY
%F contents_97_02
%K Galaxies
%B LGS 3 presents the optical appearance of a dwarf spheroidal galaxy, but has a significant neutral hydrogen component.
Photometry of its brightest stars with COSMIC at the prime focus of the Hale telescope shows a 10 (superscript 8) year
old population and a 10 (superscript 10) year old population. Either we are seeing a recent burst of star formation in a
dwarf spheroical galaxy, or, if intermediate age populations are also present, we are witnesing recent transition from a
dwarf irregular to a dwarf spheroidal galaxy.

%R 1997PASP..109..130M
%J-139
%T Increasing a Telescope's Field of View, and Subsequent Observations of Edge-On Galaxies NGC 4244 and NGC 5907
%A MARCUS DAVID
%F contents_97_02
%K Galaxies
%B A unique focal reducer for the Steward Observatory 2.3 m Ritchey-Chretien telescope on Kitt Peak was designed and
built. It increased the field of view and a Loral 2048 X 2048 charged couple device (CCD) with 15 mu m pixels from about
5' x 5' to 24` x 24`. The inverted-Cassegrainian, two-mirror design permits high efficiency of UV wavelengths and good
broad band image quality from 3500 A to 8500 A without significant chromatic aberrations. Other features include a
coronagraph and a filter slide in the slow f/9 beam which achieves the difficult and useful combination of narrow band
imaging with a wide field of view. THe filter slide tilts to vary the center wavelength of narrow interference filters
to accommodate different red shifts. The image quality is seeing-limited in the central 12' diameter, and degraded by
about 0.8" in the central 18' diameter, and degraded by 1-2" at the edges of the field. The development of hte optical
system prescription is briefly discussed. The instrument is used to obtain continuum-corrected H-alpha and [S II] images
of the edge-on galaxies NGC 4244 and NGC 5907. Interesting filamentary structure is evident. THe distribution of ionized
hydrogen gas in NGC 4244 and NGC 5907 is quantified. THe data indicates those galaxies do not have an extended halo like
that in NGC 891 and our Galaxy.

%R 1997PASP..109..140B
%J-150
%T Towards Asteroseismology from Space: the EVRIS Experiment. I. The Photometer: Description and Calibration
%A BUEY J.T., AUVERGNE M., VUILLEMIN A., EPSTEIN G.
%F contents_97_02
%K Astronomical Instrumentation
%B EVRIS is the first space experiment dedicated to asteroseismology. It will be launched on board the MARS 96 Russian
spacecraft in November 1996. The main goal of the experiment is to detect solar-like oscillations in main sequence
stars, with relative amplitudes of a few ppm. The detector is a multiplier phototube working in counting mode. To reach
the necessary sensitivity, it will work at a very high counting rate (> 10superscript6 counts s superscript-1). The
instrumental perturbations on the signal must be kept at one tenth of the photon noise level. This paper describes
experiments and calibrations showing that the unavoidable limitation of the photon noise can be obtained in these
conditions, for frequencies higher than 0.1 mHz. A nine-day experiment gives a reliable estimate of the true noise level
in Fourier space.

%R 1997PASP..109..151D
%J-165
%T Heterodyned Holographic Spectroscopy
%A DOUGLAS N.G.
%F contents_97_02
%K Astronomical Instrumentation
%B In Holographic Spectroscopy an image of an interference pattern is projected onto a detector and transformed back to
the input spectrum. The general characteristics are similar to those of Fourier Transform Spectroscopy, but the spectrum
is obtained without scanning. In the Heterodyned arrangement one or more diffraction gratings are used so that high
resoulution spectra can be recorded without a corresponding increase in the recording density. The technique offers
interesting possibilities, but is not without difficulties. The purpose of this paper is to review recent developments,
especially in astronomical applications, to describe teh theoretical background to typical problems such as coherence
losses, and to discuss the extent to which these can be solved in practical instrumention.

%R 1997PASP..109..166C
%J-172
%T Errors in Elliptical Gaussian Fits
%A CONDON J.J.
%F contents_97_02
%K Computing and Data Analysis
%B Elliptical Gaussian fits are used in astronomy for accurate measurements of fundamental source parameters such as
central position, peak flux density, and angular size. The full value of a noise-limited image can be realized only if
the effects of noise on the fitted parameters are estimated accurately. This paper presents the equations of error
propagation for two-dimensional elliptical Gaussian fits in the presence of Gaussian noise plus a new method that
simplifies the use of a priori size constraints to reduce amplitude errors.

%R 1997PASP..109..173D
%J-207
%T Atmospheric Intensity Scintillation of Stars
%A DRAVINS DAINIS, LINDEGREN LENNART, MEZEY EVA, YOUNG ANDREW T.
%F contents_97_02
%K Atmospheric Phenomena and Seeing
%B Stellar intensity scintillation in the optical was extensively studies at the astronomical observatory on La Palma
(Canary Islands). Photon-counting detectors and digital signal processors recorded temporal auto-and cross-correlation
functions, power spectra, and probability distributions. This first paper of a series treats the temporal properties of
scintillation, ranging from microseconds to seasons of year. Previous studies, and the mechanisms producing
scintillation are reviewed. Atmospheric turbulence causes 'flying shadows' on the ground, and intensity fluctuations
occur both because this pattern is carried by winds, and is intrinsically changing. On very short timescales, a break in
the correlation functions around 300 mus may be a signature of an inner scale (approx. 3 mm in the shadow pattern at
windspeeds of ms -1). On millisecond timescales, the autocorrelation decreases for smaller telescope apertures until
approx. 5 cm, when the 'flying shadows' become resolved. During any night, timescales and amplitudes evolve on scales of
tens of minutes. In good summer conditions, the flying-shadow patterns are sufficiently regular and long-lived to show
anti-correlation dips in autocorrelation functions, which in winter are smeared out by apparent wind shear. Recordings
of intensity variance together with stellar speckle images suggest some correlation between good [angular] seeing and
large scintillation. Near zenith, the temporal statistics (with up to 12:th order moments measured)is best fitted by a
Beta distribution of the second kind (F-distribution), although it is well approximated by log-normal functions,
evolving with time.

%R 1997PASP..109..208E
%J-214
%T The Feasibility of Forecasting Cirrus Cloud Cover and Water Vapor Above Telescope Sites in Northern Chile
%A ERASMUS D.A., PETERSON R.
%F contents_97_02
%K Atmospheric Phenomena and Seeing
%B This paper presents the results of a study conducted to examine the feasibility of forecasting cirrus cloud cover and
atmospheric water vapor at European Southern Observatory (ESO) telescope sites in Chile at Paranal and La Silla. 6.7 mum
imagery from the Meteosat-3 satellite was used to quantify water vapor and cirrus cloud cover conditions above the
sites. Using these data in conjunction with upper-air meteorological data, a method was developed to forecast the amount
and type of cirrus cloud cover and water vapor above the telescopes. Forecasts were made of moisture and cloud
parameters for four periods in 1993 and 1994 and evaluated by an objective comparison of forecasted and measured values.
The results clearly indicate that it is feasible to forecast water vapor and cirrus cloud conditions above Paranal and
La Silla with an accuracy that would be useful for telescope scheduling.

%R 1997PASP..109..215O
%J-215
%T Optical Observations of Black-Hole X-ray Novae
%A OROSZ J.A.
%F contents_97_02
%K Dissertation Summary
%B The primary aim of this thesis was to increase the number of dynamically confirmed black hole X-ray novae (BHXNs). As
a result of this research, the optical counterpart of an GRO J1655-40 (XN Sco94) has been discovered (Bailyn et al.
1995), and the mass functions of GRO J0422+32, H 1705-250 (XN Oph77), and GRO J1655-40 have been measured (Orosz &
Bailyn 1995; Remillard et al. 1996; Bailyn et al. 1995). In addition, the measurements of fundamental system properties
of several BXHNs have been refined. Finally, some of the overall properties of the BHXNs as a class are discussed.

%R 1997PASP..109..216M
%T Erratum: "A Photometric Analysis of the Binary System of KO Aquilae"
%A MADER J.A., ANGIONE R.J.
%F contents_97_02
%K Erratum
%B The numbers in rows 2 and 3 of Table 3 are interchanged. The correct Table 3 is provided.