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In December 2018, the main-belt asteroid (6478)~Gault was reported to display activity. Gault is an asteroid belonging to the Phocaea dynamical family and was not previously known to be active, nor was any other member of the Phocaea family. In this work we present the results of photometric and spectroscopic observations that commenced soon after the discovery of activity. We obtained observations over two apparitions to monitor its activity, rotation period, composition, and possible non-gravitational orbital evolution. We find that Gault has a rotation period of $P = 2.4929 \pm 0.0003$ hours with a lightcurve amplitude of $0.06$ magnitude. This short rotation period close to the spin barrier limit is consistent with Gault having a density no smaller than $\rho = 1.85$~g/cm$^3$ and its activity being triggered by the YORP spin-up mechanism. Analysis of the Gault phase curve over phase angles ranging from $0.4^{\circ}$ to $23.6^{\circ}$ provides an absolute magnitude of $H = 14.81 \pm 0.04$, $G1=0.25 \pm 0.07$, and $G2= 0.38 \pm 0.04$. Model fits to the phase curve find the surface regolith grain size constrained between 100-500 $\rm{\mu}$m. Using relations between the phase curve and albedo we determine that the geometrical albedo of Gault is $p_{\rm v} = 0.26 \pm 0.05$ corresponding to an equivalent diameter of $D = 2.8^{+0.4}_{-0.2}$ km. Our spectroscopic observations are all consistent with an ordinary chondrite-like composition (S, or Q-type in the Bus-DeMeo taxonomic classification). A search through archival photographic plate surveys found previously unidentified detections of Gault dating back to 1957 and 1958. Only the latter had been digitized, which we measured to nearly double the observation arc of Gault. Finally, we did not find any signal of activity during the 2020 apparition or non-gravitational effects on its orbit., Comment: 15 pages, 11 figures; Accepted in MNRAS

Nine point sources appeared within half an hour on a region within $\sim$ 10 arcmin of a red-sensitive photographic plate taken in April 1950 as part of the historic Palomar Sky Survey. All nine sources are absent on both previous and later photographic images, and absent in modern surveys with CCD detectors which go several magnitudes deeper. We present deep CCD images with the 10.4-meter Gran Telescopio Canarias (GTC), reaching brightness $r \sim 26$ mag, that reveal possible optical counterparts, although these counterparts could equally well be just chance projections. The incidence of transients in the investigated photographic plate is far higher than expected from known detection rates of optical counterparts to e.g.\ flaring dwarf stars, Fast Radio Bursts (FRBs), Gamma Ray Bursts (GRBs) or microlensing events. One possible explanation is that the plates have been subjected to an unknown type of contamination producing mainly point sources with of varying intensities along with some mechanism of concentration within a radius of $\sim$ 10 arcmin on the plate. If contamination as an explanation can be fully excluded, another possibility is fast (t $, 21 pages, 3 figures, 1 table. Published in Scientific Reports. Supplementary information can be found on the publishers webpage (open access)

The arrivals of the new more accuracy reference catalogues and also development of new meth- ods and approaches for reduction astrometric data give the new life for photographic plates archives. Gaia DR2 is not only a giant step in the astrometric accuracy allowing to measure new objects also provides plates archives ob- served in the past with modern accuracy. In this work we present the first results of astrometric reduction in the sys- tem of Gaia DR2 for some photographic plates that were obtained by UK Schmidt telescope (UKST) and digitized by the SuperCOSMOS scanning machine. The UKST is a classical Schmidt with the following parameters: mirror diameter 1.83m; focal length 3.07m; photographic plate size 356mm square, covering 6.4 x 6.4 degrees of sky; plate scale 67.12 arcsec/mm. To date the UKST has taken over 17,000 plates, the plates are stored in the Plate Li- brary at the Royal Observatory, Edinburgh. The photo- graphic plates are digitized to 15 bits (32768 grey levels) with a resolution of 10 microns (0.67 arcsec)/pixel). Each digitized Schmidt plate has size 32256x32256 pixels and produces about 2 Gbyte pixel data .. We are making new reduction of photographic plates that allowing to provide valuable data for future researches in astrometry as well as in astrophysics. The obtained astrometric and photometric data from photographic plates were compared with same one from modern catalogues.

We have determined the rate of large accretion events in class I and II young stellar objects (YSOs) by comparing the all-sky digitised photographic plate surveys provided by SuperCOSMOS with the latest data release from Gaia (DR2). The long mean baseline of 55 years along with a large sample of class II YSOs ($\simeq$15,000) allows us to study approximately 1 million YSO-years. We find 139 objects with $\Delta R\geq1$~mag, most of which are found at amplitudes between 1 and 3 mag. The majority of YSOs in this group show irregular variability or long-lasting fading events, which is best explained as hot spots due to accretion or by variable extinction. There is a tail of YSOs at $\Delta R\geq3$~mag and they seem to represent a different population. Surprisingly many objects in this group show high-amplitude irregular variability over timescales shorter than 10 years, in contrast with the view that high-amplitude objects always have long outbursts. However, we find 6 objects that are consistent with undergoing large, long lasting accretion events, 3 of them previously unknown. This yields an outburst recurrence timescale of 112 kyr, with a 68\% confidence interval [74 to 180] kyr. This represents the first robust determination of the outburst rate in class II YSOs and shows that YSOs in their planet-forming stage do in fact undergo large accretion events, and with timescales of $\simeq$100,000 years. In addition, we find that outbursts in the class II stage are $\simeq$10 times less frequent than during the class I stage., Comment: 22 pages, 11 figures, accepted for publication in MNRAS

The New Astrometric Reduction of Old Observations (NAROO) center can be found at the Paris Observatory in Meudon, and it is dedicated to the measurement of astrophotographic plates and the analysis of old observations. The NAROO digitizer consists of a granite-based Newport-Microcontrol open-frame air-bearing XY positioning table, a scientific sCMOS camera, and a telecentric optical system. The plate holder assembly is suited for mounting glass plates up to 350 mm squared. The machine positioning stability is better than 15 nm, and its repeatability is better than 40 nm. With real photographic plate data, we were able to produce measurements with an accuracy better than 65 nm. The renewed interest about photographic plates concerns the expansion of the database of transient objects evolving in time, since digitization now makes it possible to measure images with a high level of accuracy and to identify all the available objects. The information extracted from such materials can be of an astrometric, photometric, and spectroscopic nature, when not purely imaging, with consequences in planetology, near-Earth asteroid risk assessment, astrophysical phenomena, and general relativity, to mention but a few. Through our scientific program in the Gaia era, we detail examples of current and upcoming uses for the community. We invite researchers to use our facilities and digitize their collection by answering our call for proposals.

We demonstrate the feasibility of determining magnitudes of stars on archival photographic plates using a commercially available scanner. We describe one photometric approach that could serve as a useful example for other studies. In particular, we measure and calibrate stellar magnitudes from a 1903 photographic plate from the Yerkes Observatory collection, and demonstrate that the overall precision from our methods is better than 0.10 mag. Notably, these measurements are dominated by intrinsic plate noise, rather than noise introduced through the scanning/digitization process. The low expense of this approach expands the scientific potential to study variable stars in the archives of observatory plate collections. We use the serendipitous discovery of a candidate transient at photographic magnitude $pg$ = 16.60 in the spiral galaxy NGC 7331 to illustrate our photometric methods. If this unknown source is a supernova, it would represent the fourth known supernova in NGC 7331., 12 pages, 11 figures, submitting to PASP; comments welcome

The paper presents the first results of processing of photographic observations of SS bodies based on materials from the collection of plates of the Ulug Bek Astronomical Institute of theAcademyofSciencesof theRepublicofUzbekistan(AI ASRUz). The glass archive of the AI AI ASRUz has about 15 thousand photographic plates with images of various space objects. In this paper, we discuss the first results of processing of major planets’ photographic observations inUzbekistanusing the new technique. The observations were carried out on two astrographs –Tashkentnormal astrograph (TNA, D/F=330/3438) and Kitab Double Zeiss astrograph (DAZ, D/F=400/3000) in 1895-2004. Currently, in AI the work runs to streamline the archive and create a database of observations in a single xls-format. The number of photographic plates with images of major planets obtained on two telescopes is more than 300 negatives. In 2017, together with MAO NAS ofUkraine, the processing of these photographic observations using the new methodology was started. The plate digitization is performed on the flat-bed 10000XL in 1200dpi mode. Positions and photometric estimations in B-color of all registered on the plate objects are obtained using the software proposed and developed in MAO NAS of Ukrainerunning in LINUX/MIDAS/ROMAFOT environment. The search for major planets and their satellites among the whole set of plate objects and the comparison of their observed and predicted positions is carried out online with the help of internet-service (http://lnfm1.sai.msu.ru/neb/nss/nssephmr.htm). Up to date, the small part of the plate collection is treated, namely 23 negatives with images of Uranus, Neptune, Pluto and Saturn’s satellites, obtained on the Kitab DAZ astrograph. 16 negatives with 19 exposures gave the best results with (О-С) in the range ±1.5″. In total, we obtained 47 astrometric positions of the objects of interest in the wide interval of brightness’s (8m ±16m). The internal positional accuracy of the catalog in the Tycho-2 reference system is σαδ= 0.08″–0.13″, the photometric error of B-magnitudes is estimated as σB = 0.2m.

We present an atlas composed of more than 1500 spectra of late-type stars (spectral types from G to M) observed simultaneously in the optical and calcium triplet spectral ranges. These spectra were obtained as part of a survey to search for cool supergiants in the Magellanic Clouds and were taken over four epochs. We provide the spectral and luminosity classification for each spectrum (71% are supergiants, 13% are giants or luminous giants, 4% are carbon or S stars, and the remaining 12% are foreground stars of lesser luminosities). We also provide a detailed guide for the spectral classification of luminous late-type stars, the result of the extensive classification work done for the atlas. Although this guide is based on classical criteria, we have put them together and re-elaborated them for modern CCD-spectra as these criteria were scattered among many different works and mainly conceived for use with photographic plate spectra. The result is a systematic, well-tested process for identifying and classifying luminous late-type stars, illustrated with CCD spectra of standard stars and the classifications of our own catalogue., Accepted for publication in A&A. The atlas of spectra and the complete list of targets will be available at CDS, once the paper is published

The nearest known binary brown dwarf WISE J104915.57-531906.1AB (LUH 16) is a well-studied benchmark for our understanding of substellar objects. Previously published astrometry of LUH 16 obtained with FORS2 on the Very Large Telescope was affected by errors that limited its use in combination with other datasets, thereby hampering the determination of its accurate orbital parameters and masses. We improve upon the calibration and analysis of the FORS2 astrometry with the help of Gaia DR2 to generate a high-precision dataset that can be combined with present and future LUH 16 astrometry. We demonstrate its use by combining it with available measurements from the Hubble Space Telescope (HST) and Gemini/GeMS and deriving updated orbital and mass parameters. Using Gaia DR2 as astrometric reference field, we derived the absolute proper motion and updated the absolute parallax of the binary to 501.557 +/- 0.082 mas. We refined the individual dynamical masses of LUH 16 to 33.5 +/- 0.3 M[Jupiter] (component A) and 28.6 +/- 0.3 M[Jupiter] (component B), which corresponds to a relative precision of ~1% and is three to four times more precise than previous estimates. We found that these masses show a weak dependence on one datapoint extracted from a photographic plate from 1984. The exact determination of a residual mass bias, if any, will be possible when more high-precision data can be incorporated in the analysis., Comment: 11 pages, 7 figures, 7 tables, accepted for publication in A&A on August 14, 2018

Photographic plate archives contain a wealth of information about positions and brightness celestial objects had decades ago. Plate digitization is necessary to make this information accessible, but extracting it is a technical challenge. We develop algorithms used to extract photometry with the accuracy of better than ~0.1m in the magnitude range 130.2m) variable stars. The algorithms are implemented in the free software VaST available at http://scan.sai.msu.ru/vast/, Comment: 4 pages, 3 figures; proceedings of the IAU Symposium 339 Southern Horizons in Time-Domain Astronomy, 13-17 November 2017, Stellenbosch, South Africa

The recent extensive digitisation of astronomical photographic plate archives, the development of new dedicated software and the use of powerful computers have for the first time enabled effective data mining in extensive plate databases, with wide applications in various fields of recent astrophysics. As an example, analyses of supermassive binary black holes (binary blazars) require very long time intervals (50 years and more), which cannot be provided by other data sources. Examples of data obtained from data mining in plate archives are presented and briefly discussed.

Astrometric calibration is based on patterns of cataloged stars and therefore effectively assumes a particular epoch, which can be substantially incorrect for historical images. With the known proper motions of stars we can "run back the clock" to an approximation of the night sky in any given year, and in principle the year that best fits stellar patterns in any given image is an estimate of the year in which that image was taken. In this paper we use 47 scanned photographic images of M44 spanning years 1910-1975 to demonstrate this technique. We use only the pixel information in the images; we use no prior information or meta-data about image pointing, scale, orientation, or date. Blind Date returns date meta-data for the input images. It also improves the astrometric calibration of the image because the final astrometric calibration is performed at the appropriate epoch. The accuracy and reliability of Blind Date are functions of image size, pointing, angular resolution, and depth; performance is related to the sum of proper-motion signal-to-noise ratios for catalog stars measured in the input image. All of the science-quality images and 85 percent of the low-quality images in our sample of photographic plate images of M44 have their dates reliably determined to within a decade, many to within months., Comment: submitted to AJ

Using recent data from photometric monitoring and data from the photographic plate archives we aim to study, the long-term photometric behavior of FUors. The construction of the historical light curves of FUors could be very important for determining the beginning of the outburst, the time to reach the maximum light, the rate of increase and decrease in brightness, the pre-outburst variability of the star. Our CCD photometric observations were performed with the telescopes of the Rozhen (Bulgaria) and Skinakas (Crete, Greece) observatories. Most suitable for long-term photometric study are the plate archives of the big Schmidt telescopes, as the telescopes at Kiso Observatory, Asiago Observatory, Palomar Observatory and others. In comparing our results with light curves of the well-studied FUors, we conclude that every new FUor object shows different photometric behavior. Each known FUor has a different rate of increase and decrease in brightness and a different light curve shape., Comment: 4 pages, 5 figures, accepted for publication in the International Astronomical Union Proceedings Series

Since the most ancient times astronomers felt the need to collect and list in atlases and catalogs all the visible objects in the sky the first stellar catalog known in the western world being the one of Hipparchus (II century BC). We have to wait until Charles Messier at the end of the XVIII century to have the first incidental catalog of nebulae, i.e. including a mixture of fuzzy objects, nebulæ, that telescopes of the epoch could detect. In Chapter 1 we have already discussed the atlases and catalogs that soon after the discovery of galaxies appeared in the literature describing the properties of the nearby galaxies, in particular their morphologies in Chapter 3. The subject of extragalactic papers, during the photographic plate era, were one or few galaxies, whose properties were carefully scrutinized looking at all details resolved by telescopes in the optical waveband. This happens also today, of course, basically at all wavelengths. However, the impact of new technologies permits in the last two decades to tackle survey programs addressed to the study of specific extragalactic problems considering millions of galaxies. These systematic investigations of enormous galaxy samples requires dedicated observing, reduction and storing/retrieval facilities provided, in the Big Science era, by international consortia. Data are treated in a statistically way, combining the multi-wavelength information coming from several instruments, scanning galaxy properties as a function of the redshift and of the environment. The big teams of scientists and engineers that has planned and built the instrumental facilities, including sometimes the telescopes themselves, are also charged of providing a nearly immediate access to the data, as well as their maintenance and calibration. The data are easy available through simple queries on the web. Usually one of the main step of these large teams is to build a catalog of the detected sources, providing the first measures typically obtained from automatic softwares of analysis. These data are then cross-correlated with other data available for the same sources in the web databases, possibly refined with better calibration. Relations between entries are evaluated and discussed at the light of theoretical models and simulations by members of the same team. Observations have the strong tendency to produce facts so models are refined and data-set revisited and/or integrated with new observations. This Chapter is dedicated to galaxy surveys. It is even difficult to offer a complete overview of the enormous number of galaxy surveys today available and/or ongoing. We interviewed scientists asking them to present the most significant surveys, in their view, in their area of scientific interest and emphasized the main results obtained by the surveys that have seen their active collaboration. Before entering the core of such discussion George Paturel will provide us in Section 5.2 a much clear idea of the efforts that are necessary to build a good galaxy catalogue and to homogenize the entries in a database. The information about the single galaxies are indeed so wide that a new concept of data managing has been developed: the Virtual Observatory (see Section 9.9). Since the beginning of the astronomical use of photographic techniques, big plates archives are preserved basically in all observatories. Thanks to their large field of view and easy storability, astronomers often re-used this patrimony over the time, e.g. to follow time variable phenomena or to inspect several different objects in the field of view of the plates. Along this line Virtual Observatories have been conceived for providing an easy retrieval of the multiple types of data available for individual objects. In Section 5.3 Alessandro Boselli and Laura Ferrarese will characterize the galaxy environments that are coming out from the various sky surveys, dealing in particular with the Virgo and Fornax clusters, our closer biggest associations of galaxies. Then, in Section 5.3.1 Bianca Poggianti will draw the picture emerging from WINGS, the WIde field Galaxy cluster Survey, dedicated to the study of the nearby (z < 0.07) galaxy clusters. Nils Bergvall (Section 5.3.2) and Valentina Karachentseva (Section 5.3.2) will present the properties of galaxies inhabiting the low density environments up to isolation. Martha Haynes and Riccardo Giovanelli will discuss the HI surveys in Section 5.4 and related subsections. Luciana Bianchi will introduce the UV surveys, with a particular emphasis for the results obtained by GALEX in Section 5.5.1. The most important IR and X ray surveys will be discussed by Alessandro Boselli and Ginevra Trinchieri respectively in Section 5.5.2 and 5.5.3. Finally, in Section 5.6 Jonathan Bland-Hawthorn and Bianca Poggianti will give a panoramic sketch of the main spectroscopic surveys.

We derive the proper motions, membership probabilities, and velocity dispersions of stars in the regions of the young (about 2-4 Myr-old) open clusters NGC 2244 (the central cluster in the Monoceros R2 association) and NGC 6530 (the dominant cluster in the Sgr OB1 association) from photographic plate material obtained at Shanghai Astronomical Observatory, with time baselines of 34 and 87 years, respectively. Both clusters show clear evidence of mass segregation, but they do not exhibit any significant velocity-mass (or, equivalently, a velocity-luminosity) dependence. This provides strong support for the suggestion that the observed mass segregation is -- at least partially -- due to the way in which star formation has proceeded in these complex star-forming regions (``primordial'' mass segregation). Based on arguments related to the clusters' published initial mass functions, in conjunction with our new measurements of their internal velocity dispersions (35 and 8 km/s for NGC 2244 and NGC 6530, respectively), we provide strong arguments in favor of the dissolution of NGC 2244 on very short time-scales, while we speculate that NGC 6530 may be more stable against the effects of internal two-body relaxation. However, this latter object may well be destroyed by the strong tidal field prevalent at its location in the Galactic plane in the direction of the Galactic Center., Comment: 36 pages, 10 figures, accepted to AJ

Apparatus is described for the purpose of automated grain mapping of polycrystalline samples within a laboratory environment, using a motorized sample stage and a CCD detector. The limitations that come from using a faster detector of relatively small surface are countered using an automated translation stage., Although CCD X-ray detectors can be faster to use, their large-area versions can be much more expensive than similarly sized photographic plate detectors. When indexing X-ray diffraction patterns, large-area detectors can prove very advantageous as they provide more spots, which makes fitting an orientation easier. On the other hand, when looking for single crystals in a polycrystalline sample, the speed of CCD detectors is more useful. A new setup is described here which overcomes some of the limitations of limited-range CCD detectors to make them more useful for indexing, whilst at the same time making it much quicker to find single crystals within a larger polycrystalline structure. This was done by combining a CCD detector with a six-axis goniometer, allowing the compilation of images from different angles into a wide-angled image. Automated scans along the sample were coupled with image processing techniques to produce grain maps, which can then be used to provide a strategy to extract single crystals from a polycrystal.

This result could have been proved by the Greeks more than two thousand years ago, so we certainly did not expect it to be a new theorem. However, since we found it (1996) we have asked a large number of experts, we have searched the literature, and we have posted queries on the internet, all without finding anyone who has heard of the theorem. We thus feel comfortable in concluding that the theorem is, if not unknown, at least not well known. If a reader of this note knows a reference to the theorem or to related facts, we would appreciate being informed. Before we give a mathematical proof of the theorem, we will explain in principle how the theorem was discovered experimentally. An extremely short light pulse is emitted in a wide range of directions from a point A. The duration of the light pulse is about 1 picosecond = 10−12 seconds, which produces a light pulse of length about 0.3 mm. As the light hits an arbitrary fixed plane π , it is scattered in all directions. At a point B, different from A, a “photograph” is taken with extremely short exposure time. The outcome of the experiment is that a bright circle is seen on the photographic plate. In other words, a bright curve—which is actually an ellipse—is seen on the plane π , and this curve looks circular as viewed from B. (The technique used to carry out such experiments is described in [2].) How can we interpret this experiment as supporting our theorem? Well, let us assume that photons are emitted precisely at time t = 0 from the point A and that the “photograph” is taken at time t = t1 > 0. Then photons originating at A can contribute to the picture only if their travel time is exactly t1, and hence the distance that they have travelled is exactly s = ct1, where c is the speed of light. This means that for any photon that has made one bounce at some point P on the plane π on its way from A to B, the sum of the distances AP and P B must be equal to s. What is the locus of the set of all such points P? If for a moment we forget about the plane π , the locus of all the points P in space such that the sum of the distances AP and P B is equal to s is a rotational ellipsoid E with axis of symmetry through A and B and focal points at A and B. Accordingly the set of bounce points P on the plane π is the curve in which π intersects E . This is the bright curve that is viewed by our camera located at the point B. It is an elementary fact that this curve is an ellipse, and as already explained, the assertion of the theorem is that this curve looks circular when viewed from B.

We present an application of Mathematical Morphology (MM) for the classification of astronomical objects, both for star/galaxy differentiation and galaxy morphology classification. We demonstrate that, for CCD images, 99.3 +/- 3.8 % of galaxies can be separated from stars using MM, with 19.4 +/- 7.9 % of the stars being misclassified. We demonstrate that, for photographic plate images, the number of galaxies correctly separated from the stars can be increased using our MM diffraction spike tool, which allows 51.0 +/- 6.0 % of the high-brightness galaxies that are inseparable in current techniques to be correctly classified, with only 1.4 +/- 0.5 % of the high-brightness stars contaminating the population. We demonstrate that elliptical (E) and late-type spiral (Sc-Sd) galaxies can be classified using MM at an accuracy of 91.4 +/- 7.8 %. It is a method involving less `free parameters' than current techniques, especially automated machine learning algorithms. The limitation of MM galaxy morphology based on seeing and distance is also presented. We examine various star/galaxy differentiation and galaxy morhpology classification techniques commonly used today, and show that the above MM techniques compare very favourably., 13 pages, 11 figures, accepted for publication in PASA

We report the discovery of 152 new high proper motion systems (mu >= 0.4"/yr) in the southern sky (Declination = -47 degrees to 00 degrees) brighter than UKST plate R_{59F} =16.5 via our SuperCOSMOS-RECONS (SCR) search. This paper complements Paper XII in The Solar Neighborhood series, which covered the region from Declination = -90 degrees to -47 degrees and discussed all 147 new systems from the southernmost phase of the search. Among the total of 299 systems from both papers, there are 148 (71 in Paper XII, 77 in this paper) new systems moving faster than 0.5"/yr that are additions to the classic ``LHS'' (Luyten Half Second) sample. These constitute an 8% increase in the sample of all stellar systems with mu >= 0.5"/yr in the southern sky. As in Paper XII, distance estimates are provided for the systems reported here based upon a combination of photographic plate magnitudes and 2MASS photometry, assuming all stars are on the main sequence. Two SCR systems from the portion of the sky included in this paper are anticipated to be within 10 pc, and an additional 23 are within 25 pc. In total, the results presented in Paper XII and here for this SCR sweep of the entire southern sky include five new systems within 10 pc and 38 more between 10 and 25 pc. The largest number of nearby systems have been found in the slowest proper motion bin, 0.6"/yr > mu >= 0.4"/yr, indicating that there may be a large population of low proper motion systems very near the Sun.

We present Lick Natural Guide Star Adaptive Optics observations of the L8 brown dwarf Gliese 337C, which is resolved for the first time into two closely separated (0. 53±0. ′′ 03), nearly equal magnitude components with a Ks flux ratio of 0.93±0.10. Companionship is inferred from the absence of a 3. 6 offset source in 2MASS or photographic plate images, implying that the observed secondary component is a co-moving late-type dwarf. With a projected separation of 11 AU and nearly equalmagnitude components, Gliese 337CD has properties similar to other known companion and field substellar binaries. Its long orbital period (estimated to be �140-180 yr) inhibits short-term astrometric mass measurements, but the Gliese 337CD system is ideal for studying the L/T transition at a fixed age and metallicity. From a compilation of all known widely separated (&100 AU) stellar/brown dwarf multiple systems, we find evidence that the binary fraction of brown dwarfs in these systems is notably higher than that of field brown dwarfs, 45 +1513 % versus 18 +74 % for analogous samples. We speculate on possible reasons for this difference, including the possibility that dynamic (ejection) interactions which may form such wide pairs preferentially retain binary secondaries due to their greater combined mass and/or ability to absorb angular momentum. Subject headings: binaries: visual — stars: individual (Gliese 337CD) — stars: low mass, brown dwarfs

We report the discovery of 141 new high proper motion systems (1.0"/yr > mu >= 0.4"/yr) in the southern sky (Declination = -90 degrees to -47 degrees) brighter than UKST plate R_{59F} = 16.5 via our SuperCOSMOS-RECONS (SCR) search. When combined with the nine systems having mu >= 1.0"/yr and/or late spectral type from the initial phases of this effort (Hambly et al. 2004, Henry et al. 2004), we find that 73 of the 150 total systems are moving faster than 0.5"/yr, and are therefore new members of the classic "LHS" (Luyten Half Second) sample. These constitute a 21% increase in the sample of stars with mu >= 0.5"/yr in the declination region searched, thereby comprising an important addition to this long-neglected region of the sky. Distance estimates are provided for the entire sample, based upon a combination of photographic plate magnitudes and 2MASS photometry, using the relations presented in Hambly et al. (2004) for the presumed main sequence stars. Three systems are anticipated to be within 10 pc, and an additional 15 are within 25 pc. Eight of these 18 nearby systems have proper motions falling between 0.4"/yr and 0.6"/yr, hinting at a large population of nearby stars with fast, but not extremely high, proper motions that have not been thoroughly investigated.

A total of 1095 magnitude estimates for the long‐period classical Cepheid GY Sge (P = 51 days), derived from the photographic plate collections of Harvard College Observatory, Sonneberg Observatory, and Sternberg Astronomical Institute, were combined with 48 new radial velocity measures obtained using the correlation spectrometer on the 1 m reflector of the Crimean Astrophysical Observatory. The data, in combination with published photometry (including observations from the All Sky Automated Survey 3) and radial velocity measurements, cover a time baseline spanning 116 years. The resulting O - C data display evolutionary changes in the period of GY Sge amounting to + 203 ± 27 s yr−1, a value in good agreement with theoretical predictions for a star in the third crossing of the instability strip. Large cyclical drifts with durations of ~23,000 days superposed on the parabolic evolutionary trend in the O - C data exhibit the positive signature of random fluctuations in pulsation period, of magnitude similar to what is found in other pulsating stars of similar period.

Synchrotron X–ray reticulography measures lattice–plane orientation variations point by point on the crystal with microradian resolution capability. A fine–scale X–ray–absorbing mesh placed close to the crystal in the back–reflected diffracted beam of ‘white’ X–rays splits the beam into an array of microbeams whose direction differences are measured from the mesh–bar shadow shifts that result from controlled changes of the distance between the mesh and the recording high–resolution photographic plate. In the present work, lattice tilts were measured on either side of a growth–sector boundary outcropping at the surface of a single–crystal synthetic diamond cut and polished parallel to (110) in which the displacements and strains due to lattice–parameter mismatch at coherent growth–sector boundaries have been analysed in part I. Attention was concentrated on a crystallographically well–defined planar segment of a boundary separating two sectors, each of uniform, but significantly differing, concentration of substitutional nitrogen impurity, and for which the anisotropic elasticity theory of part I provided quantitative relations between the lattice–parameter relative difference, Δa/ā, and the lattice tilts due to coherency strains at the boundary. This enabled a novel method for determining Δa/ā to be realized, using reticulographic measurements of tilts of near–surface lattice planes alone. The paper explains the reticulographic technique fully. Factors affecting the quality and reliability of reticulographic records are examined in detail. For the growth sectors concerned, the reticulographic measurement Δa/ā = (1.10 ± 0.10) × 10−5 is in accord with an earlier finding by synchrotron X–ray double–crystal diffractometry, slightly revised as recommended in part I, Δa/ā = (1.20 ± 0.07) × 10−5. The closeness of the findings by two quite different methods confirms the conclusion from X–ray topography that the growth–sector boundary was free from misfit dislocations compensating the lattice–parameter mismatch. On mismatch boundaries in crystals too highly absorbing for transmission X–ray topography, such comparisons of reticulographic and diffractometric measurements would reveal information otherwise inaccessible by non–destructive methods.

We evaluated the use of a commercial flatbed scanner for digitizing photographic plates used for spectroscopy. The scanner has a bed size of 420 mm by 310 mm and a pixel size of about 0.0106 mm. Our tests show that the closest line pairs that can be resolved with the scanner are 0.024 mm apart, only slightly larger than the Nyquist resolution of 0.021 mm expected from the 0.0106 mm pixel size. We measured periodic errors in the scanner using both a calibrated length scale and a photographic plate. We find no noticeable periodic errors in the direction parallel to the linear detector in the scanner, but we find errors with an amplitude of 0.03 to 0.05 mm in the direction perpendicular to the detector. We conclude that large periodic errors in measurements of spectroscopic plates using flatbed scanners can be eliminated by placing the plate along the short side of the scanner and scanning the plates with the dispersion direction parallel to the linear detector.

Results of an experimental study of possible ways to extend the capabilities of a big size transmission type holographic screen are presented. Different approaches to the problem of making a big size screen have been considered and tested experimentally. Up to 60 $\times$ 80 $\textrm{cm}^2$ screens have been recorded on a single photographic plate VRP-M. By attaching a mirror behind the screen, the reflection mode of operation has been obtained. In this arrangement some additional peculiarities appear in the screen, which can be used to extend the screen capabilities. The first possibility is to increase the screen size by mosaicking the subscreens in the reflection mode of operation. Screens of 120 $\times$ 80 $\textrm{cm}^2$ and 180 $\times$ 40 $\textrm{cm}^2$ have been obtained by proper alignment of 60 $\times$ 40 $\textrm{cm}^2$ subscreens. The second possibility is to move the viewing Bone by rotation of the screen together with the mirror and thereby realize by the eye-tracking capability. Methods of increasing vertical size of the viewing zone have been considered. Along with the multi-exposure method, which was considered in previous papers, addition of the vertical diffuser with the optimized scattering angle has been tested experimentally. The vertical size of the viewing zone has been increased by up to 10-15 cm. Another method consists of usage of a diffraction grating with vertical dispersion to solve the same problem.

Underwater photography first appeared on the screen of modern visual consciousness at the ornate Palace of Optics at the Paris Universal Exhibition of 1900. Far from being a benign distraction, this new medium revealed optics itself to be in a state of suspended animation. A cursory inventory of the Palace's contents-a reading of its architectural cross section, evenreveals the outline of the situation. Planned as a working observatory, the Palace housed a colossal refracting telescope that promised to produce the "largest, brightest, and most distinct" photographs possible of the celestial vault.' Representing the leading edge in resolution, the telescope was part of an international project to catalogue the night sky. Indeed, photography had become the reason for, and not only the result of, new advances in optics. What such a claim meant for the progress of vision, however, is another question. The fact that photography represented "a different kind of retina than the human eye" had already been noted by one prominent astronomer, who reported that certain nebulae visible through a telescope failed to expose a photographic plate, and others that made a photographic impression could not be seen by the eye.2 That this fact was interpreted as an argument against the "blindness" of animals living in the "pretended darkness" of the ocean's depths points to an unusual space that had opened up between vision and visuality.3 What appeared on the screen at the Palace was the notion of a visual milieu.

We present the absolute proper motion of Nova Velorum 1999=V382 Vel based on photographic plate material from the Yale/San Juan Southern Proper Motion program. The absolute motion, on the system of the International Celestial Reference System, is μαcos δ = -11.5 ± 2.3 and μδ = -1.7 ± 1.9 mas yr−1. This proper‐motion measure adds to the growing number of such measures for novae and will eventually allow the secular parallax for this class of objects to be determined.We also report the preoutburst B and V photometry of V382 Vel. In its quiescent state, the nova has mean values of V = 16.56 and B−V = 0.14. A brightening by 0.5 mag is noted in 1970 (JD 2,440,705.542).

An experiment is described in which two semi-transparent reticles and a photographic plate separated by several centimeters are illuminated by a monochromatic point source in a typical in-line configuration. The resulting shadowgram is a hologram that contains information from both reticles. Illuminating this complex hologram with a similar point source with the reticles removed produces reconstructed real images at two separate locations whose coordinates are predicted from simple theory, and also produces virtual images of the reticles at their original coordinates. This experimentally confirms the three-dimensional capability of an in-line hologram. As imaging devices such as charge-coupled device sensors become cheaper and of higher resolution, a simple demonstration of this aspect of holograms, which can be projected to an audience, can be observed by sliding the image sensor along the axis.

Reflection type high-speed holographic microscopy is applied to photograph the bifurcation of fast propagating cracks in PMMA. The cracks are of the opening mode. Spatial resolution is more than 180 lines/mm, frame interval is 5μs and the number of frames is three. A crack at bifurcation is recorded as three successive holograms on one photographic plate by means of angle-multiplexing holography. Lens assisted reconstruction method is used to reconstruct separately the three crack images from the holograms. The reconstructed crack images are magnified and photographed through a conventional microscope. The photographs show that, at bifurcation, several crack tips are running simultaneously in a small region about 1 mm in diameter. And also shown is dynamic three dimensional behavior of crack front edges or microcracks at bifurcation.

Astrometry (positions and proper motions) and photographic BVR photometry were determined from a set of 29 photographic plates and CCD data in a region of 2.3 degrees x 2.3 degrees in the area of open clusters NGC 1750 and NGC 1758 in Taurus. The iterative central overlap algorithm was used for the proper motion calculations. Plate-to-plate transformations and astrometric magnitude effects are discussed in detail. CCD data interact with photographic material ill three different ways: for the elimination of astrometric magnitude effects,, for the photometric standard calibration of photographic plates and for building a CCD pseudo-plate used for astrometric purposes as any other photographic plate. A preliminary analysis of the resulting photometric and astrometric catalogue con firmed the reality of two different clusters in the zone (NGC 1750 and NGC 1758). There were no indications for the existence of NGC 1746.

As with virtually all photographic plate material, the astrograph plates from which the Southern Proper Motion (SPM) catalog is being compiled suffer from magnitude-dependent systematic shifts in the image positions, i.e., a magnitude equation. If left uncorrected, these would adversely affect both the primary goals of the SPM catalog, the absolute proper motions, and the faint secondary reference frame. Using the diffraction-grating images present on the plates, a procedure is adopted that allows a spatially variant magnitude equation correction to be derived individually for each SPM plate. Application of the method to ~120 SPM fields, primarily around the south Galactic pole and the -30° and -35° declination zones, demonstrates its effectiveness. Indeed, the method proves superior, in the case of the SPM, to a direct calibration of the magnitude equation using the newly available Tycho Catalogue. The result of the diffraction-grating technique is final SPM positions and proper motions that are largely magnitude equation–free, as verified by numerous internal and external checks.

We present trigonometric, photometric, and photographic distances to 1748 southern ($\delta \leq$0$^\circ$) M dwarf systems with $\mu \ge$ 0\farcs18 yr$^{-1}$, of which 1404 are believed to lie within 25 parsecs of the Sun. The stars have 6.67 $\leq$ $V_J$ $\leq$ 21.38 and 3.50 $\leq$ ($V_J-K_s$) $\leq$ 9.27, covering the entire M dwarf spectral sequence from M0.0V through M9.5V. This sample therefore provides a comprehensive snapshot of our current knowledge of the southern sky for the nearest M dwarfs that dominate the stellar population of the Galaxy. Roughly one-third of the 1748 systems, each of which has an M dwarf primary, have published high quality parallaxes, including 179 from the RECONS astrometry program. For the remaining systems, we offer photometric distance estimates that have well-calibrated errors. The bulk of these ($\sim$700) are based on new $V_JR_{KC}I_{KC}$ photometry acquired at the CTIO/SMARTS 0.9m telescope, while the remaining 500 primaries have photographic plate distance estimates calculated using SuperCOSMOS $B_JR_{59F}I_{IVN}$ photometry. Confirmed and candidate subdwarfs in the sample have been identified, and a census of companions is included., Comment: accepted by The Astronomical Journal on 25 July, 2014; 75 pages of tables, 11 figures

We describe the results of a survey for moderately bright quasars performed in a 20.6-square-degree field around the galaxy NGC 450. The quasar candidates were selected on the basis of their ultraviolet excess: by comparative visual inspection of the double image of each single object on a U /B dual-exposure Schmidt photographic plate, 95 primary and 45 secondary quasar candidates were selected on the basis of their U image being too bright. The spectroscopic identification of the primary candidates led to the discovery of 59 bona fide quasars (out of which 6 were previously known). The Palomar Schmidt plate was digitised using the MAMA measuring machine and the outcoming data reduced using ad hoc procedures. A photometric calibration allowed us to derive values for the limiting magnitudes and for the index selection threshold of the survey. A catalogue containing 60 quasars is presented with accurate positions, magnitudes and additional information such as redshifts. We studied the spatial distribution of the objects and detected, for the quasars of our sample, a significant deviation from randomness in the form of a propensity to cluster in pairs on the celestial sphere with a typical scale of about 10 arcmin. We also formally detected a tendency towards a 3-D clustering, but this result is induced by a single pair of quasars. A forthcoming paper will deal with a similar work performed in a field around NGC 520; the latter field is located directly to the North of the present one and slightly overlaps it.

Astrometry in the solar system made more progress during the past ten years than it did during the seven or eight decades before. In fact, the development of large refractors with micrometers, and after the improvement of the photographic technique, allowed one to get very accurate positions at the end of the 19th century. After that, relatively little progress was made. Astronomers faced several difficulties: first, was the poor sensitivity of the photographic plates leading to long exposures and therefore to low accuracy for faint objects; second, was the poor quality of the catalogues of stars which depended upon a very small number of available astrometric reference stars.New receptors appeared around the 1950, such as electronic cameras or T.V. tubes. But, most of these new receptors were not interesting for astrometry, mainly because of the field of view – which was too small – and of the difficulty of using such receptors. However, the development of a new technique based upon the CCD targets changed most of the astrometric observational programs. In fact, CCD receptors were made for small fields, but the CCDs were easy to use; the images were numerical, allowing processing by computers, and the sensitivity was much more important. Because of that, the accuracy increased and relative astrometry was developed. The recent development of new catalogues, such as the Guide Star Catalogue and Tycho, permits astronomers to reduce small fields, which was not possible earlier.

We analyzed the 100-yr light curves of Galactic high-mass X-ray binaries using the Harvard photographic plate collection, made accessible through the DASCH project (Digital Access to a Sky Century at Harvard). As scanning is still in progress, we focus on the four objects that are currently well covered: the supergiant X-ray binary Cyg X-1 (V1357 Cyg), and the Be X-ray binaries 1H 1936+541 (BD+53 2262), RX J1744.7-2713 (HD 161103), and RX J2030.5+4751 (SAO 49725), the latter two objects being similar to g Cas. The star associated with Cyg X-1 does not show evidence for variability with an amplitude higher than 0.3 magnitude over a hundred years. We found significant variability of one magnitude with timescales of more than 10 years for SAO 49725, as well as a possible period of 500‐600 days and an amplitude of 0.05 magnitude that might be the orbital, or super-orbital period of the system. The data is insufficient to conclude for HD 161103 but suggests a similar long-term variability. We thus observe an additional characteristic of g Cas-like objects: their long-term variability. This variability seems to be due to the slow evolution of a decretion disk around the Be star, but may be triggered by the presence of a compact object in the system, possibly a white dwarf. This characteristic could be used to identify further similar objects otherwise difficult to detect.

We carried out BVRI CCD photometric observations in the field of V582 Aur from 2009 August to 2013 February. We acquired high-, medium-, and low-resolution spectroscopy of V582 Aur during this period. To study the pre-outburst variability of the target and construct its historical light curve, we searched for archival observations in photographic plate collections. Both CCD and photographic observations were analyzed using a sequence of 14 stars in the field of V582 Aur calibrated in BVRI. The pre-outburst photographic observations of V582 Aur show low-amplitude light variations typical of T Tauri stars. Archival photographic observations indicate that the increase in brightness began in late 1984 or early 1985 and the star reached the maximum level of brightness at 1986 January. The spectral type of V582 Aur can be defined as G0I with strong P Cyg profiles of H alpha and Na I D lines, which are typical of FU Orionis objects. Our BVRI photometric observations show large amplitude variations V~2.8 mag. during the 3.5 year period of observations. Most of the time, however, the star remains in a state close to the maximum brightness. The deepest drop in brightness was observed in the spring of 2012, when the brightness of the star fell to a level close to the pre-outburst. The multicolor photometric data show a color reversal during the minimum in brightness, which is typical of UX Ori variables. The corresponding spectral observations show strong variability in the profiles and intensities of the spectral lines (especially H alpha), which indicate significant changes in the accretion rate. On the basis of photometric monitoring performed over the past three years, the spectral properties of the maximal light, and the shape of the long-term light curve, we confirm the affiliation of V582 Aur to the group of FU Orionis objects., 9 pages, 8 figures, accepted for publication in A&A

Astrometric accuracy has two components; the accuracy with which an image can be centred on a CCD or photographic plate and the accuracy with which two image centres can be mapped on to standard co-ordinates. Photographic plates cover a sufficient area of sky that several standard stars can be measured with the satellite images and the mapping to standard coordinates can be done in one operation. CCDs have much smaller areas and the number of stars with sufficiently accurate positions may not be sufficient. The surface densities of the best available catalogues are shown in Table I.

The history of astrometry, the branch of astronomy dealing with the positions of celestial objects, is a lengthy and complex chronicle, having its origins in the earliest records of astronomical observations more than two thousand years ago, and extending to the high accuracy observations being made from space today. Improved star positions progressively opened up and advanced fundamental fields of scientific enquiry, including our understanding of the scale of the solar system, the details of the Earth's motion through space, and the comprehension and acceptance of Newtonianism. They also proved crucial to the practical task of maritime navigation. Over the past 400 years, during which positional accuracy has improved roughly logarithmically with time, the distances to the nearest stars were triangulated, making use of the extended measurement baseline given by the Earth's orbit around the Sun. This led to quantifying the extravagantly vast scale of the Universe, to a determination of the physical properties of stars, and to the resulting characterisation of the structure, dynamics and origin of our Galaxy. After a period in the middle years of the twentieth century in which accuracy improvements were greatly hampered by the perturbing effects of the Earth's atmosphere, ultra-high accuracies of star positions from space platforms have led to a renewed advance in this fundamental science over the past few years., 52 pages, 14 figures. To appear in The European Physical Journal: Historical Perspectives on Contemporary Physics

Photographic images are valuable data resources for studying long term changes in the solar magnetic field and its influence on the Earth's climate and weather. We digitized more than 100 years of white light images stored in photographic plates and films that are available at Kodaikanal observatory starting from 1904. The digitized images were calibrated for relative plate density and aligned in such a way that the solar north is in upward direction. A semi-automated sunspot detection technique was used to identify the sunspots on the digitized images. In addition to describing the calibration procedure and availability of the data, we here present preliminary results on the sunspot area measurements and their variation with time. The results show that the white-light images have a uniform spatial resolution throughout the 90 years of observations. However, the contrast of the images decreases from 1968 onwards. The images are circular and do not show any major geometrical distortions. The measured monthly averaged sunspot areas closely match the Greenwich sunspot area over the four solar cycles studied here. The yearly averaged sunspot area shows a high degree of correlation with the Greenwich sunspot area. Though the monthly averaged sunspot number shows a good correlation with the monthly averaged sunspot areas, there is a slight anti-correlation between the two during solar maximum The Kodaikanal data archive is hosted at http://kso.iiap.res.in. The long time sequence of the Kodaikanal white light images provides a consistent data set for sunspot areas and other proxies. Many studies can be performed using Kodaikanal data alone without requiring intercalibration between different data sources., Comment: 9 pages, A&A(accepted)

For the measurement of vibrations using double-pulse techniques, pulses separations between 1 and 1000 microseconds are necessary. Until now double-pulsed holographic interferometry has been extensively used to measure vibrations. This method has the disadvantage that it needs the recording and the reconstruction of a hologram. For the recording a photographic plate or a thermo-plastic camera is usually used. The hologram is then reconstructed usually with a continuous laser and viewed with a CCD camera. This process is time consuming. Double pulsed ESPI [1] enables to obtain correlation fringes corresponding to the displacement without recourse to any form of photographic processing and plate relocation.

The APM facility in Cambridge has been used to search archive UK Schmidt Telescope photographic plates for an optical counterpart of SGR 1806-20. The search has revealed a late-type variable star just outside the revised 3 σ error box. A low-resolution spectrum of the star suggests that it is almost undoubtedly an M9 Mira

By the early years of the twentieth century, astronomers regarded photography as one of the most valuable tools at their disposal, a technique which not only provided an accurate and reliable representation of astronomical phenomena, but also radically changed the role of the astronomical observer. Herbert Hall Turner, professor of astronomy at Oxford, wrote in 1905: ‘The wonderful exactness of the photographic record may perhaps best be characterised by saying that it has revealed the deficiencies of all our other astronomical apparatus – object-glasses and prisms, clocks, even the observer himself.’ H. C. Russell, government astronomer in Sydney, suggested that photography might in the future make the observer redundant: ‘In many cases the observer must stand aside while the sensitive photographic plate takes his place and works with the power of which he is not capable… I feel sure that in a very few years the observer will be displaced altogether.’ Such visions were not uncommon at the time, emanating from the trust invested in the photographic process after the spectacular achievements of the late nineteenth century.

The readout properties of the specklegram recorded in a photorefractive Bi(12)SiO(20) (BSO) crystal plate have been investigated by observing the Young fringes and the polarization change of the light transmitted from the BSO plate. The Young fringes can be obtained without an analyzer by any linearly polarized readout beam; they have higher visibility than those obtained from a photographic plate specklegram, since the specklegram recorded in the BSO crystal can be read out by the spatial distribution of both the degree of polarization and the azimuth angle of polarization. Selective interference of a kind is performed.

Two simple methods are described to improve the quality of images blurred by either defocusing or a uniform rectilinear motion of the photographic plate during the exposure. They both consist of simultaneously recording on a silver chloride emulsion two incoherent images of the input blurred signal, perpendicularly polarized and conveniently slightly shifted. The strength of anisotropy induced in the plate is proportional to the differene between the intensities of the images, i.e., to the derivative of the input signal. In the case of defocusing, the two images are radially shifted and one reconstructs, after exposure, the contours of the input signal. In the case where the degradation is due to a uniform rectilinear motion, the two images are laterally shifted and the reconstructed signal consists of two images of the original object.

Phase-locked moire systems have the advantage of rapid data acquisition and accuracy of better than one twentieth of the fringe spacing. In conventional moire systems data acquisition is performed by making a photographic plate and taking measurements from the plate either visually or with a microdensitometer. This is slow, and the accuracy is about one-quarter of the fringe spacing. The phase-locked system is more accurate and permits a more favorable trade-off between accuracy and working depth. The equations governing moire contouring are examined, and the theory of phase-locked moire fringe analysis is presented. The design and operation of the phase-locked moire contouring system are described, and the results of measurements made with the instrument are presented.

This paper presents a new coherent optical method whereby the partial derivatives of the contour of an object are measured. The object to be studied is immersed in a refractive medium and is imaged by a camera with a shearing device. The processed photographic plate which has been doubly exposed in the image plane with the refractive medium changed between the exposures can be Fourier filtered to yield a fringe pattern depicting derivatives of the surface contour with respect to the direction of shearing. This new method enjoys the advantages of being simple and less demanding in vibration isolation, coherence of light source, and film resolution.

A Ronchi ruling is photographed through a phase object that deforms the grating lines. The object is displaced longitudinally, and a second exposure is made. After developing, the photographic plate is observed with a frequency-plane mask that cuts off all but one of the diffracted orders. A lateral-shear interferogram of the phase object is obtained in this way. The experiment may be carried out by making multiple exposures and by displacing the object through equal distances after each exposure. This will produce a multiple-beam lateral-shear interferogram, and the fringes become very sharp.

With the help of a simple ground glass and a photographic plate the phase variations of a transparent object can be studied. The object is interposed between the source and the ground glass. The photographic plate, kept behind the ground glass, is exposed successively twice, with and without the object. When properly illuminated the negative gives the variation in the derivative of the phase of the object, and this observation can be made in white light.