Women in Glass: Women at the Harvard Observatory during the Era of Astronomical Glass Plate Photography, 1875–1975

Starting in the late 19th century, the Harvard Observatory hired women to study stars via the Astronomical Photographic Glass Plate Collection. Some of these women—such as Annie Jump Cannon, Henrietta Leavitt, and Cecilia Payne-Gaposchkin—made discoveries that changed astrophysics forever. However, they were far from the only women working at the Harvard Observatory during the era of astronomical glass plate photography. Historically, most of these women have been anonymous. The names found on over 400,000 glass plate envelopes were compiled into a list of all the women who left their mark on the collection between 1875 and 1975. Through this list of names, it is revealed that Harvard’s glass plate collection acted as a haven for women who wanted to study the stars, long before they found equality in the field of astronomy.

Evaluation of Ground Reaction Forces and Limb Symmetry Indices Using Ground Reaction Forces Collected with One or Two Plates in Dogs Exhibiting a Stifle Lameness

Objective The aim of the study was to evaluate the efficiency and consistency in the collection of ground reaction forces using one or two force plates from dogs with stifle lameness. Animals Twenty-two client-owned dogs with unilateral stifle lameness were used. Methods In a prospective study design, data were collected at a single time point using both one- and two-plate collection methods. Ground reaction forces collected included peak vertical force, vertical impulse and associated symmetry indices. Additionally, time required to obtain valid trials and the total number of trials were also recorded for both one-plate and two-plate collections. Linear mixed models were used to analyse differences in peak vertical force, vertical impulse and symmetry indices between the collection methods. A paired-T test was used to compare trial number and time of trial collection. The significance threshold was p < 0.05. Results It took significantly longer to collect valid trials using one-plate both in time (16.1 ± 8.0 minutes vs, 8.0 ± 4.3 minutes with two plates) and number of trials (33.8 ± 14.8 trials vs. 16.4 ± 8.8 trials with two plates) (p < 0.0001). There was no difference in peak vertical force or vertical impulse data between collection methods. Neither the peak vertical force symmetry indices nor the vertical impulse symmetry indices were significantly different between one- and two-plate collection techniques. Conclusion The total time and number of trials needed to collect valid trials in dogs with stifle lameness were minimized through the use of two force plates. However, there was no significant difference in the ground reaction force or symmetry index values collected between the two systems.

The period–luminosity relation of red supergiants with Gaia DR2

We revisit the K -band period–luminosity (P–L) relations of Galactic red supergiants using Gaia Data Release 2 parallaxes and up to 70 yr of photometry from AAVSO and ASAS campaigns. In addition, we examine 206 LMC red supergiants using 50 yr of photometric data from the digitized Harvard Astronomical Plate Collection. We identified periods by computing power spectra and calculated the period–luminosity relations of our samples and compared them with the literature. Newly available data tighten the P–L relations substantially. Identified periods form two groups: one with periods of 300–1000 d, corresponding to pulsations, and another with Long Secondary Periods between 1000 and 8000 d. Among the 48 Galactic objects we find shorter periods in 25 stars and long secondary periods in 23 stars. In the LMC sample we identify 85 and 94 red supergiants with shorter and long secondary periods, respectively. The P–L relation of the Galactic red supergiants is in agreement with the red supergiants in both, the Large Magellanic Cloud and the Andromeda galaxy. We find no clear continuity between the known red giant period–luminosity sequences, and the red supergiant sequences investigated here.

In Living Color: Crystal Bridges and its American Color Plate Collection

Since opening, Crystal Bridges has generated a great deal of interest from the public and cultural institutions. From the construction of a 185,000 square foot facility in the bottom of a ravine, to the much-discussed art acquisitions and features in national media, this attention is hardly surprising. However, beyond the building and the art, Crystal Bridges also has an art research library with many rare books and the most important collection of American color printed books in North America. These diverse resources presented unique challenges to the librarians, as well as to the cataloger, specifically in accurately researching and describing these significant items.

Digital Archive of the Astrograph Plates Stored at the Inasan Zvenigorod Observatory

The plate collection of the Zvenigorod 40-cm Carl Zeiss astrograph, obtained in 1972-2003, contains direct photographs of star fields, comets, asteroids, Pluto, and Mars. The electronic library of images from photographic plates was created from scanning the astronomical negatives. We present information on programs scheduled at the telescope and the structure and maintenance of the plate stacks. We also list the plates with images of asteroids and comets. Access to all our plate lists is provided at the web sites of the Institute of Astronomy (INASAN) and WFPDB. It is possible to select plates by the date of observation, by the coordinates of the sky area, by the object type. Preview images can be inspected.