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We reconsider the already published phenomenon of the blue shift of diffuse interstellar bands, observed in spectra of HD34078 (AE Aur) and members of the Sco OB1 association, in particular HD152233. We have analyzed 29 diffuse bands. Some of them, already proven as blue-shifted in our earlier study, are now confirmed using another instrument: the 6.5 m Clay telescope equipped with the MIKE spectrograph. The high signal-to-noise ratio (over 600) of our spectra allowed us to reveal even small small-scale displacements of positions (both blue and redshifts) of diffuse bands along the considered lines of sight. In some cases, the magnitude of deviation exceeds 10 km s-1. Also, we prove that profiles of many diffuse bands in spectra of HD34078 suffer significant broadening. The origin of the observed phenomena is discussed.

The first decade of the 21st century and the last few years of the 20th have been transformative for ground- and space-based observational astronomy due to new observing facilities, access to digital archives, and growth in use of the Internet for communication and dissemination of information and for access to the archives. How have these three factors affected the characteristics and content of papers published in refereed astronomical journals, as well as the journals themselves? In this and subsequent papers I will propose answers to this question. The analysis in this, the first paper of a series, is based on an examination of the 100 most cited papers in astronomy and astrophysics for each year between 2000 and 2009, inclusive, and supplemental data from 1995 and 1990. The main findings of this analysis are: Over the 10 yr period the totalnumber of authors of the top-100 articles year-1has more than tripled. This increase is seen most strongly in papers with more than six authors. The number of uniqueauthors in any given year has more than doubled. The yearly number of papers with five or fewer authors has declined over the same time period. Averaged over the 10 yr period the normalized number of authors per paperincreases steadily with citation rank-the most highly cited papers tend to have the largest number of authors and vice versa. This increase is especially notable for papers ranked 1 through 20 in terms of number of citations andnumber of authors. The distributionof normalized citation counts versus ranking is remarkably constant from year to year and, except for the top-ranked half-dozen or so papers in each year, is very closely approximated by a power law. Nearly all of the papers that show the most divergence from the power-law fit-all in the sense of having a high number of citations-are based on the results of large observational surveys. Among the top-100 papers there is a small but significant correlation of paper length with citation rank. More striking, though, is that the average page length of the top-100 papers is one and a half times that for astronomy papers in general. For every year from 2000 to 2008, the same five journals account for 80 to 85% of the totalcitations for each year from all of the journals in the category of "Astronomy and Astrophysics" by ISI's Journal Citation Reports. These numbers do not include Natureor Science. Averaged over the 10 yr time period studied in this article, these same five journals account for 77% of the 1000 most cited papers, slightly less than the journals' fractional contribution to the totalnumber of articles published by all journals. The five journals are A&A, AJ, ApJ, ApJS, and MNRAS. Two samples of the top-100 cited papers, both for the 6 yr from 2001 to 2006 but compiled 2.5 yr apart, show that a significant number of articles originally ranked in the top 100 for the year, drop out, and are replaced by other articles as time passes. Most of the dropouts address topics in extragalactic astronomy; their replacements for the most part deal with non-extra-galactic topics. Finally, some additional findings are noted that relate to the entire ensemble of astronomical journals published during the century's first decade. Various indicators of Internet access to astronomical Web sites such as data archives and journal repositories show increases of between factors of 3 and 10 or more. I propose that there are close complementarities between the communication capabilities that Internet usage enables and the strong growth in numbers of authors of the most highly cited papers. Subsequent papers will examine this and other interpretations of the analysis presented here in detail.

We have investigated the temporal variability and statistics of the "instantaneous" Strehl ratio. The observations were carried out with the 3.63-m AEOS telescope equipped with a high-order adaptive-optics system. In this paper Strehl ratio is defined as the peak intensity of a single short exposure. We have also studied the behavior of the phase variance computed on the reconstructed wavefronts. We tested the Maréchal approximation and used it to explain the observed negative skewness of the Strehl ratio distribution. The estimate of the phase variance is shown to fit a three-parameter Gamma distribution model. We show that simple scaling of the reconstructed wavefronts has a large impact on the shape of the Strehl ratio distribution.

In this paper we present an error analysis for polarimetric data obtained with dual-beam instruments. After recalling the basic concepts, we introduce the analytical expressions for the uncertainties of polarization degree and angle. These are then compared with the results of Monte Carlo simulations, which are also used to briefly discuss the statistical bias. We then approach the problem of background subtraction and the errors introduced by an imperfect Wollaston prism, flat-fielding, and retarder plate defects. Finally, we investigate the effects of instrumental polarization and propose a simple test to detect and characterize it. The application of this method to real VLT-FORS1 data has shown the presence of a spurious polarization that is of the order of ?1.5% at the edges of the field of view. The cause of this problem has been identified as the presence of rather curved lenses in the collimator, combined with the incomplete removal of reflections by the coatings. This problem is probably common to all focal-reducer instruments equipped with a polarimetric mode. An additional spurious and asymmetric polarization field, whose cause is still unclear, is visible in the Bband.

We present broadband BVIphotometry for the open cluster NGC 6791, based upon analysis of 1764 individual CCD images. We discuss in detail the transformation of the instrumental magnitudes to the standard photometric system of Landolt and then discuss methods for selecting a subset of cluster stars whose photometric indices are most likely to be of high reliability. Color-magnitude and color-color diagrams for the cluster are presented and discussed. A detailed comparison of this photometry with the results of previous observational studies is presented. We make preliminary comparisons with theoretical isochrones provided by D. A. VandenBerg and conclude that an excellent match can be achieved if the metal abundance and age of the cluster are both near the upper end of the range of recent estimates ([Fe/H]???+0.3, age???12 Gyr) and the reddening and true distance modulus are both near the low end of the range of recent estimates [E(B?V)???0.09 mag and (m?M)0???12.79 mag] if the isochrone predictions are reliable. A companion paper will discuss candidate variable stars and stars possibly showing planetary transits. Data tables listing measured magnitudes and standard errors, image-quality indices, a variability index, and equinox J2000.0 equatorial coordinates for 14,342 stars to V?24 have been made available to the public through the services of the Canadian Astronomy Data Centre. Equatorial coordinates only have been provided for a further 1916 stars, the photometry for which we were unable to calibrate because of lack of color information.

Changes in the average length of papers and letters/short contributions in English-language astronomy, mathematics, and physical-science journals since about 1900 are investigated statistically. The results are presented in tables and graphs, and sharp increases are observed for the period 1945-1984, including a 64-percent increase in paper length 1945-1984, a 26-percent increase in letter length 1975-1984, and a 76-percent increase in letter length 1965-1984. Interpretations of these findings by the author and two historians of science, two editors of scientific journals, and one distinguished astronomer are summarized. Factors considered include both social phenomena, such as publishing budgets, manuscript-preparation techniques, language skills, and institutional pressure to publish, and the possibility of a real increase in the amount of scientific information in each paper.

We present precise and deep optical photometry of the globular M92. Data were collected in three different photometric systems: Sloan Digital Sky Survey (g', r', i', and z'; MegaCam at CFHT), Johnson-Kron-Cousins (B, V, and I; various ground-based telescopes), and Advanced Camera for Surveys (ACS) Vegamag (F475W, F555W, and F814W; Hubble Space Telescope). Special attention was given to the photometric calibration, and the precision of the ground-based data is generally better than 0.01 mag. We computed a new set of ?-enhanced evolutionary models accounting for the gravitational settling of heavy elements at fixed chemical composition ([?/Fe] = +0.3, [Fe/H] = -2.32 dex, and Y= 0.248). The isochrones-assuming the same true distance modulus (? = 14.74 mag), the same reddening [E(B- V) = 0.025 ± 0.010 mag], and the same reddening law-account for the stellar distribution along the main sequence and the red giant branch in different color-magnitude diagrams (i', g'- i'; i', and g'- r'; i', g'- z'; I, and B- I; and F814W and F475W-F814W). The same outcome applies to the comparison between the predicted zero-age horizontal-branch (ZAHB) and the HB stars. We also found a cluster age of 11 ± 1.5 Gyr, in good agreement with previous estimates. The error budget accounts for uncertainties in the input physics and the photometry. To test the possible occurrence of CNO-enhanced stars, we also computed two sets of ?- and CNO-enhanced (by a factor of 3) models, both at fixed total metallicity ([M/H] = -2.10 dex) and at fixed iron abundance. We found that the isochrones based on the former set give the same cluster age (11 ± 1.5 Gyr) as the canonical ?-enhanced isochrones. The isochrones based on the latter set also give a similar cluster age (10 ± 1.5 Gyr). These findings support previous results concerning the weak sensitivity of cluster isochrones to CNO-enhanced chemical mixtures.

We use new and extant literature spectroscopy to address abundances and membership for UMa moving group stars. We first compare the UMa, Coma, and Hyades H-R diagrams via a homogeneous set of isochrones and find that these three aggregates are essentially coeval; this (near) coevality can explain the indistinguishable distributions of UMa and Hyades dwarfs in the chromospheric emission versus color plane. Our spectroscopy of cool UMa dwarfs reveals striking abundance anomalies-trends with Teff, ionization state, and excitation potential-like those recently seen in young, cool M34, Pleaides, and Hyades dwarfs. In particular, the trend of rising ?7774-based O iabundance with declining Teffis markedly subdued in UMa compared to the Pleiades, suggesting a dependence on age or metallicity. Recent photometric metallicity estimates for several UMa dwarfs are markedly low compared to the group's canonical metallicity, and similar deviants are seen among cool Hyads as well. Our spectroscopy does not confirm these curious photometric estimates, which seem to be called into question for cool dwarfs. Despite disparate sources of Li data, our homogeneous analysis indicates that UMa members evince remarkably small scatter in the Li- Teffplane for Teff?5200 K. Significant star-to-star scatter suggested by previous studies is seen for cooler stars. Comparison with the consistently determined Hyades Li- Tefftrend reveals differences that are qualitatively consistent with this cluster's larger [Fe/H] (and perhaps slightly greater age). However, quantitative comparison with standard stellar models indicates the differences are smaller than expected, suggesting the action of a fourth parameter beyond age, mass, and [Fe/H] controlling Li depletion. The UMa-Coma cool star Li abundances may show a slight 0.2 dex difference; however, this may be mass-independent and thus more consistent with a modest initial Li abundance difference.

V697 Sco, the remnant of Nova Scorpii 1941 and currently at V?20.0, is found from photometric observations to have the characteristics of an intermediate polar with an orbital period (Porb) of 4.49 hr and a rotation period (Prot) of 3.31 hr. It therefore appears to be a member of the rare class of intermediate polars where Prot?Porb, which are probably diskless systems. The prominence of the modulation at 1 / 2 Prot, and its orbital sidebands, indicates two-pole accretion.

Long-slit spectroscopy is entering an era of increased spatial and spectral resolution and increased sample size. Improved instruments reveal complex velocity structure that cannot be described with a one-dimensional rotation curve, yet samples are too numerous to examine each galaxy in detail. Therefore, one goal of rotation curve measurement techniques is to flag cases in which the kinematic structure of the galaxy is more complex than a single-valued curve.

OF PAPERS PRESENTED AT THE BISHOP, CALIFORNIA, MEETING OF THE ASThONOMICAL SOCIETY OF THE PACIFIC, 11-13 JUNE 1974

ABSThACTS OF PAPERS PRESENTED AT THE HAWAII MEETING 22-25 WNE 1971

ABSThACTS OF PAPERS PRESENTED AT THE UNIVERSITY OF SOUTHERN CALIFORNIA MEETING OF THE ASThONOMICAL SOCIETY OF THE PACIFIC, 11-13 JUNE 1973

OF PAPERS PRESENThD AT THE SANTA CRUZ MEETING OF THE ASThONOMICAL SOCIETY OF THE PACIFIC, 26-29 JUNE 1972

The Space Telescope Imaging Spectrograph (STIS) instrument was installed on the Hubble Space Telescope(HST) during the second servicing mission, in 1997 February. Four bands cover the wavelength range of 115-1000 nm, with spectral resolving powers between 26 and 200,000. Camera modes are used for target acquisition and deep imaging. Correction for HST's spherical aberration and astigmatism is included. The 115-170 nm range is covered by a CsI MAMA (Multianode Microchannel Array) detector and the 165-310 nm range by a Cs2Te MAMA, each with a format of 2048 × 2048 pixels, while the 305-555 and 550-1000 nm ranges are covered by a single CCD with a format of 1024 × 1024 pixels. The multiplexing advantage of using these two-dimensional detectors compared with the 1 × 512 pixel detectors of the first-generation spectrographs is 1 or 2 orders of magnitude, depending on the mode used. The relationship between the scientific goals and the instrument specifications and design is discussed.

We studied the histories of the 1039 papers submitted in 1984 to the Pub. A. S.P., A.J., and Ap. J. (first half of 1984) and found that 90% were eventually accepted and published in the initial journals. Of the remainder, two-thirds never appeared in other journals and one-third (32 papers) appeared in a large variety (18) of journals, mostly nondomestic. These numbers do not differ significantly between the three journals but differ drastically from journals in fields other than the physical sciences where the acceptance rates are usually 10%-30% and authors tend to submit rejected papers to other journals rather than to revise them. Key words: publication-reviewing

For the 165 papers published in the Astrophysical Journal and Supplements in 1954, we counted the citations during 1955-1994. They show an exponential decay with a halflife of 29 yr. Papers receiving more citation than others during the first five years do not have longer halflives. This sample shows that observational papers have an average halflife (35 yrs) that is somewhat longer than for theoretical papers (22 yrs). Longer papers, such as Supplement ones, are cited more frequently on the average than short ones, such as Journal papers and, especially, Notes. Excluding Notes, 57% of the 1954 papers are still cited in 1990-1994. These durations are so long primarily because the field has been growing so rapidly--by a factor of 24 in 40 years. If normalized to a constant literature output, the average halflife would have been 6 yr. Another pertinent effect is caused by the changing fields of interest. Because studies of extragalactic objects, relative to other fields, are now 7 times more frequent than in 1954, citations to them have remained nearly constant in 40 years while citations to papers in other fields have dropped off more quickly.

Shifting the focus of Type Ia supernova (SN Ia) cosmology to the near infrared (NIR) is a promising way to significantly reduce the systematic errors, as the strategy minimizes our reliance on the empirical width-luminosity relation and uncertain dust laws. Observations in the NIR are also crucial for our understanding of the origins and evolution of these events, further improving their cosmological utility. Any future experiments in the rest-frame NIR will require knowledge of the SN Ia NIR spectroscopic diversity, which is currently based on a small sample of observed spectra. Along with the accompanying paper, Phillips et al., we introduce the Carnegie Supernova Project-II (CSP-II), to follow-up nearby SNe Ia in both the optical and the NIR. In particular, this paper focuses on the CSP-II NIR spectroscopy program, describing the survey strategy, instrumental setups, data reduction, sample characteristics, and future analyses on the data set. In collaboration with the Harvard-Smithsonian Center for Astrophysics (CfA) Supernova Group, we obtained 661 NIR spectra of 157 SNe Ia. Within this sample, 451 NIR spectra of 90 SNe Ia have corresponding CSP-II follow-up light curves. Such a sample will allow detailed studies of the NIR spectroscopic properties of SNe Ia, providing a different perspective on the properties of the unburned material; the radioactive and stable nickel produced; progenitor magnetic fields; and searches for possible signatures of companion stars.

The Carnegie Supernova Project-II (CSP-II) was an NSF-funded, four-year program to obtain optical and near-infrared observations of a "Cosmology" sample of ?100 Type Ia supernovae located in the smooth Hubble flow (0.03 ? z? 0.10). Light curves were also obtained of a "Physics" sample composed of 90 nearby Type Ia supernovae at z? 0.04 selected for near-infrared spectroscopic timeseries observations. The primary emphasis of the CSP-II is to use the combination of optical and near-infrared photometry to achieve a distance precision of better than 5%. In this paper, details of the supernova sample, the observational strategy, and the characteristics of the photometric data are provided. In a companion paper, the near-infrared spectroscopy component of the project is presented.

High-speed photometry of KUV 01584?0939 (alias Cet3) shows that it has a period of 620.26 s. Combined with its hydrogen-deficient spectrum, this implies that it is an AM CVn star. The optical modulation is probably a superhump, in which case the orbital period will be slightly shorter than what we have observed.

Of 4000 papers published in astronomy and in physics in the past 40 years, 40.3%, and 23.4%, respectively, have not been cited (referenced). However, if we limit this to the final research papers (excluding announcements, book reviews, proposals for funding, and observing time, obituaries, etc.), the fractions are 1.4% and 1.5%, respectively. So virtually all the papers in these two sciences are useful. These data also tell us that the productivities of astronomers peak at age 40.4 years. and that 43.0% were published after the age of 50 years. For physicists, the peak occurs at 36.6 years. and only 33.7% were published after the age of 50 years. Therefore physicists peak about four years earlier than astronomers and they produce 9% fewer citations after the age of 50 years.

Recently, Su et al. propose an innovative design, referred as the "SYZ" design, for China's new project of a 12 m optical-infrared telescope. The SYZ telescope design consists of three aspheric mirrors with non-zero power, including a relay mirror below the primary mirror. SYZ design yields a good imaging quality and has a relatively flat field curvature at Nasmyth focus. To evaluate the science-compatibility of this three-mirror telescope, in this paper, we thoroughly compare the performance of SYZ design with that of Ritchey-Chrétien (RC) design, a conventional two-mirror telescope design. Further, we propose the Observing Information Throughput (OIT) as a metric for quantitatively evaluating the telescopes' science performance. We find that although a SYZ telescope yields a superb imaging quality over a large field of view, a two-mirror (RC) telescope design holds a higher overall throughput, a better diffraction-limited imaging quality in the central field of view (FOV < 5') which is better for the performance of extreme Adaptive Optics (AO), and a generally better scientific performance with a higher OIT value.

In an effort to document how astronomers have become increasingly collaborative, the evolution in the fraction of refereed papers published by nauthors per year has been derived for four journals: The Astrophysical Journal(ApJ), Monthly Notices of the Royal Astronomical Society(MNRAS), The Astronomical Journal, and Astronomy & Astrophysics(A&A). Records compiled here for the ApJ and MNRAS extend back to 1920. The fraction of single-author papers has dropped steadily with time since 1940 in the ApJ and MNRAS, and at least since 1970 for the other two journals. Over a period of ?20-25 years commencing around 1980, two-author papers were more common than those by any other number of authors. Both f(2) and f(3) have since gone through a maximum in all four journals, albeit at different times, while f(4) either evinces a maximum or has leveled off. The general situation for n= 5 to 9 is the same in all four journals, with the fraction of such papers increasing steadily since 1980. For values of nin this range it is found that to 0.7 in the ApJ, MNRAS, and A&A. Among papers with n= 2, 5, and 8-10, in all four journals studied the percentage of occasions in which the first and second authors have worked at the same institution exceeds 50%.

About 15% of all citations in astronomical papers published during January 1983 were self-citations, in the sense that the cited and citing papers had at least one author in common. The self-citation rate varies surprisingly little among journals, countries, subdisciplines, and epochs, and is rather higher than has generally been thought. These data do not tell us whether the current rate of self-citations in astronomical papers is too high, too low, or just right for an active, growing science; they merely tell us what it actually is.

In 1983 I found that the most productive ages for research astronomers was 40-75 years, contradicting the frequent statement that a scientist's best work is done before the age of 35. Now most scientists work in small to large teams, unlike the individual research usually done previously. How has that affected the productive careers of astronomers? A new study of 14 recent Russell Lecturers shows a peak in productivity at age 33 and more than half that peak during 25-56 years, in agreement with results in other sciences. Nevertheless, 33% of their best work was done after the age of 50 years.

We report the discovery of HATS-15 b and HATS-16 b, two massive transiting extrasolar planets orbiting evolved (?10 Gyr) main-sequence stars. The planet HATS-15 b, which is hosted by a G9 V star (mag), is a hot Jupiter with mass of and radius of , and it completes its orbit in about 1.7 days. HATS-16 b is a very massive hot Jupiter with mass of and radius of it orbits around its G3 V parent star (mag) in ?2.7 days. HATS-16 is slightly active and shows a periodic photometric modulation, implying a rotational period of 12 days, which is unexpectedly short given its isochronal age. This fast rotation might be the result of the tidal interaction between the star and its planet.

The Robotic Observations of Microlensing Events/Reactive Event Assessment Survey was a Key Project at Las Cumbres Observatory (hereafter LCO) which continuously monitored 20 selected fields (3.76 sq.deg) in the Galactic Bulge throughout their seasonal visibility window over a three-year period, between 2017 March and 2020 March. Observations were made in three optical passbands (SDSS−g′, −r′, −i′), and LCO’s multi-site telescope network enabled the survey to achieve a typical cadence of ∼10 hr in i′and ∼15 hr in g′and r′. In addition, intervals of higher cadence (<1 hr) data were obtained during monitoring of key microlensing events within the fields. This paper describes the Difference Image Analysis data reduction pipeline developed to process these data, and the process for combining the photometry from LCO’s three observing sites in the Southern Hemisphere. The full timeseries photometry for all ∼8 million stars, down to a limiting magnitude of i∼ 18 mag is provided in the data release accompanying this paper, and samples of the data are presented for exemplar microlensing events, illustrating how the tri-band data are used to derive constraints on the microlensing source star parameters, a necessary step in determining the physical properties of the lensing object. The timeseries data also enables a wealth of additional science, for example in characterizing long-timescale stellar variability, and a few examples of the data for known variables are presented.

We considered the 242 papers published in 1977-86 in the Astrophysical Journal by 49 well-known astronomers (i.e., the living Russell, Warner, Pierce, and Heineman awardees and the AAS Presidents) plus a control group of 242 papers selected at random. We found that the numbers of reviews per paper were 1.34 and 1.37, respectively, or an insignificant 0.5? difference. The average reviewing time was 2.1? larger (42.7 days) for the papers by the well-known astronomers than for the control (40.8 days), probably because the former are longer papers on the average. The acceptance rate of 95% is higher for the former than for the control (83%), as one would expect for papers by more experienced authors. Thus, the papers by well-known astronomers do not receive significantly fewer or more-rapid reviews, but a larger fraction of them is eventually accepted.