Guest Investigator Research Articles

GUEST INVESTIGATORS AT SACRAMENTO PEAK OBSERVATORY, NEW MEXICO

GUEST INVESTIGATORS AT SACRAMENTO PEAK OBSERVATORY, NEW MEXICO

GUEST INVESTIGATORS AT THE HALE OBSERVATORIES"

GUEST INVESTIGATORS AT THE HALE OBSERVATORIES"

The HEAO-B X-ray Telescope and its Observing Program

A brief description is given of the performance characteristics of the HEAO-B X-ray telescope observatory. Particular emphasis is given to the descriptions of the parameters whose knowledge is required to establish an observational program. Since a substantial fraction of the observing time will be made available to Guest Investigators, the manner in which a Guest Investigator program may be run on the HEAO-B facility is outlined. The detailed observing program by the Consortium Institutions responsible for the HEAO-B program is summarized.

Spectroscopic Observations of the Be Stars η Cen, γ Cas and φ Per

The main part of this paper is concerned with observations obtained using the Princeton ultraviolet telescope-spectrometer on the Copernicus satellite through the Princeton guest investigator programme. These observations provided high resolution ultraviolet spectra of the bright southern shell star η Cen, which are now being analysed in detail. A short description of the new η Cen spectra and a progress report on the data analysis are presented below. In the second part of the paper we describe visible-region spectra of the northern Be stars γ Cas and φ Per obtained with a cross-dispersed echelle spectrograph on the 36-inch Yapp telescope at the Royal Greenwich Observatory.

GUEST INVESTIGATORS AT THE HALE OBSERVATORIES

GUEST INVESTIGATORS AT THE HALE OBSERVATORIES

The Orbiting Astronomical Observatory

OAO-Copernicus, launched August 21, 1972, is in its third year of successful operation. Its contributions to scientific knowledge are contained in over 37 scientific papers. Princeton University Observatory has expanded the Guest Investigator Program to include 56 programs by a total of 66 astronomers from 23 countries. Observing time is currently scheduled for twelve months in advance. The engineering features of the Perkin-Elmer-built telescope are surveyed in this paper. A digest of the scientific results and a bibliography of OAO-C related papers is given, and the nature of the investigations planned at the time of writing (September 1974) is summarized.

GUEST INVESTIGATORS AT THE HALE OBSERVATORIES

GUEST INVESTIGATORS AT THE HALE OBSERVATORIES

GUEST INVESTIGATORS AT THE HALE OBSERVATORIES

GUEST INVESTIGATORS AT THE HALE OBSERVATORIES

GUEST INVESTIGATORS AT THE MOUNT WILSON AND PALOMAR OBSERVATORIES

GUEST INVESTIGATORS AT THE MOUNT WILSON AND PALOMAR OBSERVATORIES

GUEST INVESTIGATORS AT THE MOUNT WILSON AND PALOMAR OBSERVATORIES

GUEST INVESTIGATORS AT THE MOUNT WILSON AND PALOMAR OBSERVATORIES

Notice: Guest investigators at the Mount Wilson and Palomar Observatories

Notice: Guest investigators at the Mount Wilson and Palomar Observatories

GUEST INVESTIGATORS AT THE MOUNT WILSON AND PALOMAR OBSERVATORIES

GUEST INVESTIGATORS AT THE MOUNT WILSON AND PALOMAR OBSERVATORIES

A New Gene Arrangement in the Third Chromosome of Drosophila Pseudoobscura

Journal Article A New Gene Arrangement in the Third Chromosome of Drosophila Pseudoobscura Get access DAVID W. CRUMPACKER, DAVID W. CRUMPACKER The authors are Guest Investigator and Research Associate respectively, The Rockefeller University, New York, New, York, 10021. This investigation was partially supported by Public Health Fellowship 1-F3-GM-28, 365-01, from the National Institute of General Medical Sciences, and by Contract No. AT–(30–1)–3096, No. 10, U.S. Atomic Energy Commission. The present address of Dr. Crumpacker is: Department of Agronomy, Colorado State University, Fort Collins, Colorado, 80521, and that of Dr. Kastritsis is: Department of Biology, Texas Technological College, Lubbock, Texas, 79409. The authors wish to thank Professor Th. Dobzhansky for encouragement and consultation during the course of this work. Published with the approval of the Director of the Colorado Agricultural Experiment Station as Scientific Series Paper No. 1168. Search for other works by this author on: Oxford Academic PubMed Google Scholar COSTAS D. KASTRITSIS COSTAS D. KASTRITSIS The authors are Guest Investigator and Research Associate respectively, The Rockefeller University, New York, New, York, 10021. This investigation was partially supported by Public Health Fellowship 1-F3-GM-28, 365-01, from the National Institute of General Medical Sciences, and by Contract No. AT–(30–1)–3096, No. 10, U.S. Atomic Energy Commission. The present address of Dr. Crumpacker is: Department of Agronomy, Colorado State University, Fort Collins, Colorado, 80521, and that of Dr. Kastritsis is: Department of Biology, Texas Technological College, Lubbock, Texas, 79409. The authors wish to thank Professor Th. Dobzhansky for encouragement and consultation during the course of this work. Published with the approval of the Director of the Colorado Agricultural Experiment Station as Scientific Series Paper No. 1168. Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Heredity, Volume 58, Issue 1, January 1967, Pages 3–6, https://doi.org/10.1093/oxfordjournals.jhered.a107534 Published: 01 January 1967

NEW FAINT VARIABLES NEAR THE NORTH GALACTIC POLE

Some years ago while blinking the region of the North Galactic Pole for proper motions, one of us1 found a number of suspected variables mainly of 19th-20th magnitude, many of which appeared to be white enough to suggest they might be RR Lyrae stars. Since it is obviously important to determine with certainty whether RR Lyrae stars or any other objects exist at the enormous distances indicated by these faint magnitudes, a few more plates were taken with the 48-inch Schmidt telescope in 1963 while one of us held a guest investigator ship at the Mount Wilson and Palomar Observatories.

Guest investigators at the Mount Wilson and Palomar Observatories 4

Guest investigators at the Mount Wilson and Palomar Observatories 4

Leishmaniasis in the Sudan Republic. 22. Leishmania hoogstraali sp. n. in the Gecko

The isolation of a Leishmania from 5.8% of 138 geckos (Hemidactylus turcicus) examined by culture of cardiac blood in two kala azar study areas in the southern Sudan is described. On morphological and antigenic grounds, this strain is designated as Leishmania hoogstraali sp. n. The work of Heisch (1958) and MansonBahr and Heisch (1961) in Kenya, as well as that of others, has suggested that reptilian Leishmania species should be considered in kala azar epidemiological studies. Leishmania adleri was isolated from the lizard Latastia longicaudata revoili during search for a vector of kala azar in Kenya. This species, which is antigenically more closely related to L. donovani than to any other mammalian species (Adler and Adler, 1955), produced local induration in man when inoculated intradermally or subcutaneously. The induration persisted for a month, and the parasite could be recovered up to a week after inoculation. The possibility of positive leishmanin skin reactions resulting from infection with such parasites under natural conditions was suggested. One facet of kala azar investigations recently carried out in southern Sudan by the United States Naval Medical Research Unit Number Three (NAMRU-3) was an appraisal of the possible significance of reptilian hemoflagellates in the epidemiology of the human disease. During these studies, in January and FebReceived for publication 22 September 1964. * From Research Project MR005.09-1603.9, Bureau of Medicine and Surgery, Navy Department, Washington, D. C. The opinions and assertions contained herein are the private ones of the author and are not to be construed as official or reflecting the views of the Navy Department or of the naval service at large. This study was supported in part by Research Grant E-4823 from NIAID, NIH, United States Public Health Service. A summary of this paper was presented at the First International Congress of Parasitology, Rome, in September, 1964. t School of Public Health and Tropical Medicine, University of Sydney, Australia, and Guest Investigator, Department of Medical Zoology, United States Naval Medical Research Unit Number Three, Cairo, Egypt, U.A.R. and Malakal, Upper Nile, Sudan. ruary 1963, the writer isolated from the gecko, Hemidactylus turcicus (Linnaeus), a Leishmania which is now described as a new species. The epidemiological significance of this and of another reptilian hemoflagellate found in the study area will be discussed in a future publication. MATERIALS AND METHODS Geckos (Hemidactylus spp.) were collected from the thatched roofs and walls of native tukls (huts) in two areas 100 miles apart, where kala azar has been intensively studied by NAMRU-3. These areas, in the vicinity of Paloich (32?32' E, 10?27' N) and Malakal (31039' E, 9031.5' N), Upper Nile Province, have been described by Hoog traal et al. (1962, 1963) and by Van Peenen and Reid (1963). Each gecko was prepared for cardiac puncture by lifting a small area of skin over the heart with fine forceps and removing the flap with heated scissors. After further cauterization of the exposed ar a, a sterile glass capillary, drawn to a point, was introduced into the heart for withdrawal of blood. Approximately 5 mm3 of blood was inoculated into individual tubes of Tobie's (1950) diphasic medium. The eventual mortality from a single cardiac puncture was about 20%. A thin blood film was prepared from each gecko and stained with Giemsa after fixation in methanol. Tissues were not examined for leishmanial forms. Slopes of the medium used were prepared in Cairo by adding 2.5 ml of base containing 10% of defibrinated rabbit blood together with 700 units crystalline penicillin and 700 ,ug streptomycin sulphate per ml into screw capped tubes. These were airfreighted to southern Sudan, the time in transit being about 2 weeks, and on arrival were stored in a refrigerator until used. An overlay of 1.5 ml of sterile Locke's solution containing similar concentrations of antibiotics as the base, was added to each tube before use. A low-temperature incubator was not available at the period of this investigation and cultures were held in an air-conditioned room in which temperatures ranged between 18.9 C to 27.7 C, with an average daily variation of 5.6 C. Cultures were examined for flagellate forms after about 7 days and at 21 days.

A PRELIMINARY CLASSIFICATION OF THE FORMS OF GALAXIES ACCORDING TO THEIR STELLAR POPULATION

A recent paper has given an outline of a revised system of classification of the forms of galaxies, together with types for 608 systems. That investigation will be designated Paper I, and the present one Paper II. The galaxies classified on the revised Yerkes system in Paper I include a large fraction of the northern entries in the ShapleyAmes Catalogue. It seemed advisable to make the classification approximately complete to some limiting apparent magnitude ; a program was therefore devised to classify a number of additional galaxies. Through the kindness of Dr. I. S. Bowen and the Committee of the Mount Wilson and Palomar Observatories, I was permitted to make use of the original negatives of the National Geographic Society-Palomar Observatory Sky Survey for the purpose. The present paper completes the classification of all galaxies brighter than magnitude 13.1 in the Shapley-Ames Catalogue and north of O = —25°, with two exceptions : the object NGC 2149 has been omitted from the catalogue, since it appears to be a diffuse nebulosity, rather than a galaxy; NGC 2798 was omitted inadvertently. The galaxies included in the present paper were classified on the 48-inch Sky Survey plates during a period as guest investigator at Pasadena in the autumn of 1958. A large number of galaxies in Paper I were reclassified without knowledge as to the earlier type assigned ; this overlap furnishes material for an accurate determination of the systematic characteristics of the two series. ii

PRELIMINARY CLASSIFICATION OF THE FORMS OF GALAXIES ACCORDING TO THEIR STELLAR POPULATION. II

A recent paper has given an outline of a revised system of classification of the forms of galaxies, together with types for 608 systems. That investigation will be designated Paper I, and the present one Paper II. The galaxies classified on the revised Yerkes system in Paper I include a large fraction of the northern entries in the ShapleyAmes Catalogue. It seemed advisable to make the classification approximately complete to some limiting apparent magnitude ; a program was therefore devised to classify a number of additional galaxies. Through the kindness of Dr. I. S. Bowen and the Committee of the Mount Wilson and Palomar Observatories, I was permitted to make use of the original negatives of the National Geographic Society-Palomar Observatory Sky Survey for the purpose. The present paper completes the classification of all galaxies brighter than magnitude 13.1 in the Shapley-Ames Catalogue and north of O = —25°, with two exceptions : the object NGC 2149 has been omitted from the catalogue, since it appears to be a diffuse nebulosity, rather than a galaxy; NGC 2798 was omitted inadvertently. The galaxies included in the present paper were classified on the 48-inch Sky Survey plates during a period as guest investigator at Pasadena in the autumn of 1958. A large number of galaxies in Paper I were reclassified without knowledge as to the earlier type assigned ; this overlap furnishes material for an accurate determination of the systematic characteristics of the two series. ii

THE PHASE RELATION OF THE VELOCITY AND LIGHT OF SIGMA SCORPII

The s Canis Majoris variable o Scorpii (a = 16h 15m, O = 25° 21', 1900; Bl III ; mag. 3. 1) has been the subject of numerous spectrographic investigations, the most recent being those by R. D. Levee j1 O. Struve, D. H. McNamara, and V. Zebergs ;2 and Su-Shu Huang and O. Struve.3 It has also been the subject of photoelectric studies made by J. Stebbins4 and by A. R. Hogg, K. Gottlieb, G. V. Simonow, and Beryl Hall.5 The earlier of these photometric studies served only to indicate the variable nature of the star, while the later resulted in complete light-curves. Combining the photoelectric measures of Hogg, Gottlieb, Simonow, and Hall with his own spectrographic results, Levee concluded that minimum light occurs at minimum radial velocity, a phase relationship which is inconsistent with the relations found for the other s Canis Majoris variables. In reducing the observations to a common epoch, it was necessary for Levee to bring forward the photometric observations over a time interval of 409 and 1521 days (1656 and 6161 cycles). It therefore appeared important to obtain simultaneous, or nearly simultaneous, photometric and spectrographic observations in order to investigate this relationship further. Such a set of observations, obtained on the night of 1954 May 16 U.T., is displayed in Figure 1. Photoelectric observations, made on the night of 1954 April 11, are also plotted, the reduction to the common epoch having been made by using the period P = 0.246841 day (Hogg et al.5). The radial velocities, which are from 100-inch coude spectrograms, constitute a part of the spectrographic material discussed elsewhere.2' 3 * The spectrographic material used in this paper was obtained by Mr. Struve as guest investigator at the Mount Wilson Observatory; the photoelectric material was obtained by Mr. Williams at the Lick Observatory.

Research Facilities for Guest Investigators

Research Facilities for Guest Investigators