Positions from objective prism spectra

1978 ◽  
Vol 48 ◽  
pp. 411-415
Author(s):  
J. Stock
Keyword(s):  
Radial Velocity ◽  
Radial Velocities ◽  
Observational Material ◽  
Mathematical Problems ◽  
Objective Prism ◽  
Number Of Authors

Methods for the determination of radial velocities from objective prism plates have been elaborated by a number of authors. K. Schwarzschild was probably the first to analyze the mathematical problems of the method. Fehrenbach has used the radial velocity method extensively, and also Stock and Osbom. A discussion of the possibility of determining accurate positions from the same observational material, however, has been left aside. It is the purpose of this work to show not only that positions of astrometric accuracy can obtained from objective prism plates, but also that such a method offers certain advantages over the more conventional ones.

scholarly journals Study of Spectroscopic Binaries with the Objective Prism Method

1983 ◽  
Vol 62 ◽  
pp. 104-107
Author(s):  
Frank Gieseking
Keyword(s):  
Radial Velocity ◽  
Frequency Distribution ◽  
Radial Velocities ◽  
Spectroscopic Binaries ◽  
Steep Decrease ◽  
Visual Magnitude ◽  
Objective Prism ◽  
The Individual ◽  
Large Telescopes

The frequency distribution of SB’s over apparent visual magnitude emerging from the catalogue of Batten et. al. (1978) shows a very steep decrease of the number of spectroscopically detected SB’s already for such bright stars of magnitude 7. Considering the number of all stars in the individual magnitude intervals, we find a kind of completeness parameter of the spectroscopic surveys: If we scale it somewhat optimistically at 100% between 0 and 3 mag, we see a 50% decrease of the completeness of our knowledge of stellar radial velocities already for stars fainter than 4.5 mag.This situation is mainly due to the fact that the measurement of radial velocities with conventional slit spectrographs is extremely laborious, requiring long exposure times at large telescopes for the exposure of only one spectrum at a time. – Therefore more efficient methods for radial velocity determinations of fainter stars are urgently needed.

scholarly journals La Mesure Des Vitesses Radiales Avec Un Prisme Objectif Associe A Un Telescope De Schmidt

1984 ◽  
Vol 78 ◽  
pp. 291-294
Author(s):  
Ch. Fehrenbach ◽  
R. Burnage
Keyword(s):  
Radial Velocity ◽  
Correlation Method ◽  
Probable Error ◽  
Radial Velocities ◽  
Galactic Latitude ◽  
Velocity Measurements ◽  
Schmidt Telescope ◽  
Special Machine ◽  
Objective Prism

AbstractRadial velocity measurements with an objective-prism mounted on a Schmidt telescope.A 62 cm diameter objective-prism is mounted on the CNRS-University of Liège Schmidt telescope at the Haute Provence Observatory. The field is 4 x 4° and the limiting magnitude is 12.5 on IllaJ hyper-sensitised plates. The dispersion is 200 A mm-1 at 4220 A. The plates are measured with a special machine and data are reduced by means of a computer with a correlation method. Stars of all spectral types are measured. The probable error is of some 4 km sec -1 over a mean of at least 3 plates. Already several lists of radial velocities of stars belonging to field situated at -30° of galactic latitude have been published. We have also started radial velocity observations for the Hipparcos Program.

Current Programs of Local Galactic Structure and Evolution

1984 ◽  
Vol 88 ◽  
pp. 171-176
Author(s):  
J. Andersen ◽  
B. Nordström
Keyword(s):  
Radial Velocity ◽  
Velocity Dispersion ◽  
Progress Report ◽  
Radial Velocities ◽  
Bright Star ◽  
Star Catalogue ◽  
Metal Abundance ◽  
F Stars ◽  
Near Future

AbstractWe present a progress report on some current radial-velocity observing programs aiming to provide complete data for selected samples of stars covering the whole sky. The velocities are based on ESO coudé spectra as well as CORAVEL observations obtained in both hemispheres. As a first step, the Bright Star Catalogue has been completed in radial velocities ( ~1500 stars or ~l/3 of the southern BS stars). Currently, we are approaching completion of some 4000 dwarf F stars from Olsen’s (1983) uvbyß photometric survey. The data will be used to study the velocity dispersion of these stars as a function of age and metal abundance from a kinematically unbiased sample. They will also provide a basis for an improved determination of Kz. Extension of the program to the G dwarfs is planned for the near future.

scholarly journals 30. Commission des Vitesses Radiales Stellaires

1936 ◽  
Vol 5 ◽  
pp. 188-196
Author(s):  
M. J. S. Plaskett ◽  
MM. Adams ◽  
Campbell ◽  
Frost ◽  
Guthnick ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Pacific Coast ◽  
Radial Velocities ◽  
University Of Michigan ◽  
University Of Texas ◽  
University Of Toronto ◽  
Visual Magnitude ◽  
Under Construction ◽  
The University

The three years that have elapsed since the Harvard meeting of the Union have witnessed steady progress in the determination of radial velocities. While the three large Pacific Coast Observatories have naturally been able to make the greatest additions to radial velocity work, the Yerkes Observatory, the Simeiz Observatory and the Observatory of the University of Michigan have also made valuable contributions. It is a pleasure to report that there will soon be three major accessions to the list of observatories capable of determining radial velocities. The David Dunlap Observatory of the University of Toronto with its 74-inch telescope, which should be in operation soon after the meeting, will have radial velocities as a prominent feature of its programme. The McDonald Observatory of the University of Texas with an 80-inch telescope now under construction should be ready to commence operations in 1936 and will undertake an extensive radial velocity programme. The Radcliffe Observatory at Oxford has now been granted permission by the Courts to remove to Pretoria, South Africa, and will establish there a 74-inch reflecting telescope, which will also be largely employed in the determination of the urgently needed radial velocities of the southern stars fainter than 5.5 visual magnitude. The Commission may, I believe, congratulate itself that substantial assistance in the preliminary steps leading to this permission of removal was provided by our action at the last meeting in presenting a resolution to the Union, duly passed by the General Assembly, pointing out the urgent need for additional radial velocities in the southern sky, and strongly supporting the project of the Radcliffe Observatory to establish a large telescope at Pretoria.

scholarly journals Radial Velocities for the Stars of the HIPPARCOS Mission

1992 ◽  
Vol 9 ◽  
pp. 433-436 ◽  
Author(s):  
Michel Mayor ◽  
Michèle Gerbaldi ◽  
Suzanne Grenier ◽  
Hugo Levato
Keyword(s):  
Radial Velocity ◽  
Chemical Evolution ◽  
Large Fraction ◽  
Space Mission ◽  
Radial Velocities ◽  
Solar Neighborhood ◽  
The Third ◽  
Crossing Time ◽  
Input Catalogue

A large fraction if not all of the programmes related to the study of the galactic structure, its kinematics and chemical evolution will require the knowledge of the third component of the velocity: the stellar radial velocity. But we will also need the radial velocity to be able to determine the true distribution of masses in the solar neighborhood (corrected by the crossing time of the stars in the sampled sphere). The radial velocity will allow the determination of the statistical parallax for a sample of stars lying beyond 100 parsec. At the very beginning of the development of the Hipparcos space mission, the very need for ground-based, complementary measurements has been recognized. However, in spite of the existence of new kinds of techniques or detectors, the task to provide radial velocities for the somewhat 118’000 stars of the Hipparcos Input Catalogue is quite enormous. All presently published stellar radial velocities determined since the beginning of this century represent at the most 20 to 25% of the total number of stars to be measured!

scholarly journals The Zero-Point of the IAU Standard Velocity System

1985 ◽  
Vol 111 ◽  
pp. 583-586
Author(s):  
C. D. Scarfe
Keyword(s):  
Radial Velocity ◽  
Zero Point ◽  
Radial Velocities ◽  
Orbital Elements ◽  
Camera System ◽  
Individual Stars ◽  
The Past ◽  
The Mean ◽  
Better Than

Radial velocities of bright IAU standards have been obtained photographically over the past decade using the long camera of the DAO 1.2 meter telescope's coudé spectrograph. Most of the stars observed have been found to be constant in velocity to better than 0.15 km/s over that interval. The mean velocities agree with the IAU velocities, on the average, within 0.10 km/s, although mean velocities of some individual stars differ considerably more than this from the IAU value. A preliminary determination of the zero point of the long camera system, and hence of the IAU system, has been made from observations of the asteroid Vesta, whose actual radial velocity has been calculated from its orbital elements.

scholarly journals 30. Commission des Vitesses Radiales Stellaires

1933 ◽  
Vol 4 ◽  
pp. 178-189
Author(s):  
M. J. S. Plaskett ◽  
MM. Adams ◽  
W. W. Campbell ◽  
Frost ◽  
Hamy ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Radial Velocities ◽  
University Of Michigan ◽  
International Astronomical Union ◽  
Short Summary ◽  
International Astronomical ◽  
Ann Arbor ◽  
The University

The four years that have elapsed since the last meeting of the International Astronomical Union have witnessed steady progress in the determination of radial velocities, principally at the Mt Wilson Observatory, Pasadena, Cal., the Lick Observatory, Mt Hamilton, Cal., the Yerkes Observatory, Williams Bay, Wis., the Dominion Astrophysical Observatory, Victoria, B.C., the Observatory of the University of Michigan, Ann Arbor, Mich., and the Simeis Observatory in Russia. It will be useful, for the members of the Commission, to give a short summary of the radial velocity work completed and in progress since the last meeting.

scholarly journals Search for Large Radial Velocities in Direction of NGP Using the Fehrenbach Techniques

1977 ◽  
Vol 4 (2) ◽  
pp. 63-63
Author(s):  
Alphonse Florsch
Keyword(s):  
Radial Velocity ◽  
Data Center ◽  
Radial Velocities ◽  
Growing Up ◽  
The Future ◽  
Objective Prism

The Observatory of Strasbourg will participate in the future in the general radial velocity survey which is in hand at the Observatories of Haute-Provence and of Marseille with FEHRENBACH’s Objective-prism astrograph. A programme of this type, providing a large number of data, is particularly suitable at the place where the “Data Center” is growing up.A radial velocity survey is a vast programme which needs many years to be fulfilled. It is natural that one starts with the most interesting areas in the sky, one of them being the area near NGP. In 1976 twenty fields were covered, each by one plate, in that direction. The whole programme covers 70 overlapping fields in an area of 100 square degrees centered at NGP. The limiting magnitude shall be almost the 12th.

ANALYSIS OF ACCOMPANYING PATHOLOGIES IN WOMEN WITH VARIOUS DISORDERS OF THE MENSTRUAL CYCLE

2020 ◽  
pp. 33-43
Author(s):  
Ольга Александровна Судакова ◽  
Михаил Вадимович Фролов ◽  
Алина Сергеевна Позднякова ◽  
Евгений Владимирович Белов ◽  
Данаил Красимирович Назлиев
Keyword(s):  
Antenatal Clinic ◽  
Reproductive Age ◽  
General Will ◽  
Organ Systems ◽  
Depth Analysis ◽  
Menstrual Irregularities ◽  
Positive Effect ◽  
Female Genital ◽  
Number Of Authors

Статья посвящена изучению сопутствующей патологии, у женщин репродуктивного возраста, обращающихся в стационар с жалобами на нарушения менструального цикла (НМЦ). Актуальность данной тематики не вызывает сомнения, так как с каждым годом в России и во всем мире регистрируется все большее количество случаев НМЦ. По мнению ряда авторов, данные нарушения могут составлять до 50% всех патологий женской половой сферы. Большой интерес представляет и изучение ряда сопутствующих заболеваний, которые могут отягощать течение НМЦ или наоборот, приводить к их развитию. Целью работы стал анализ разнообразной сопутствующей патологии при НМЦ, с выявлением основных причин нарушений менструального цикла у женщин фертильного возраста. Объектами исследования стали 300 пациенток, с диагнозом НМЦ, которые были разделены на 3 группы, в зависимости от уровня лечебного учреждения, где они проходили обследование - по 100 пациенток: проходивших обследование в больнице скорой медицинской помощи, обследующиеся в женской консультации и проходящие лечение сопутствующей онкопатологии в областном онкологическом диспансере. В дальнейшем проводилась дополнительное деление в каждой группе на 2 подгруппы, в зависимости от того был ли НМЦ впервые выявленным или повторно выявленным. В самой работе проводился подробный анализ сопутствующей патологии у женщин в зависимости от группы и их возраста. Определялись не только «пораженные» системы органов, но и проводился углубленный анализ по нозологиям. Работа интересна еще и тем, что в ней у всех пациенток на протяжении исследования определялся уровень стресса и наличие возможных депрессивных состояний. Определение наиболее вероятных причин НМЦ стало завершающим этапом исследования. Полученные данные могут приблизить практикующих акушеров-гинекологов к более полному пониманию различных нарушений менструального цикла, что в целом, положительно скажется на качестве и эффективности оказываемой медицинской помощи The article is devoted to the study of concomitant pathology in women of reproductive age who go to the hospital with complaints of menstrual irregularities (NMC). The relevance of this topic is beyond doubt, since every year in Russia and around the world an increasing number of cases of NMC are registered. According to a number of authors, these violations can account for up to 50% of all pathologies of the female genital area. Of great interest is the study of a number of concomitant diseases that can aggravate the course of NMC or, conversely, lead to their development. The aim of the work was to analyze a variety of concomitant pathologies in NMC, with the identification of the main causes of menstrual irregularities in women of fertile age. The objects of the study were 300 patients diagnosed with NMC, who were divided into 3 groups, depending on the level of the medical institution where they were examined - 100 patients each: who were examined in an emergency hospital, examined in an antenatal clinic and undergoing treatment for concomitant oncopathology in the regional oncological dispensary. Subsequently, an additional division was carried out in each group into 2 subgroups, depending on whether the NMC was newly detected or re-identified. In the work itself, a detailed analysis of comorbidities in women was carried out, depending on the group and their age. Not only the "affected" organ systems were identified, but an in-depth analysis of nosologies was also carried out. The work is also interesting in that during the study the level of stress and the presence of possible depressive states were determined in all patients. Determination of the most probable causes of NMC was the final stage of the study. The data obtained can bring practicing obstetricians and gynecologists closer to a more complete understanding of various menstrual irregularities, which, in general, will have a positive effect on the quality and effectiveness of medical care

scholarly journals Astrometric Radial Velocities From Hipparcos

1998 ◽  
Vol 11 (1) ◽  
pp. 564-564
Author(s):  
D. Dravins ◽  
L. Lindegren ◽  
S. Madsen ◽  
J. Holmberg
Keyword(s):  
Radial Velocity ◽  
High Precision ◽  
Radial Velocities ◽  
Radial Motion ◽  
Spectral Lines ◽  
Parallel Program ◽  
Stellar Surface ◽  
Space Astrometry ◽  
Stellar Motion ◽  
Surface Convection

Abstract Space astrometry now permits accurate determinations of stellar radial motion, without using spectroscopy. Although the feasibility of deducing astrometric radial velocities from geometric projection effects was realized already by Schlesinger (1917), only with Hipparcos has it become practical. Such a program has now been carried out for the moving clusters of Ursa Major, Hyades, and Coma Berenices. Realized inaccuracies reach about 300 m/s (Dravins et al. 1997). Discrepancies between astrometric and spectroscopic radial velocities reveal effects (other than stellar motion) that affect wavelength positions of spectral lines. Such are caused by stellar surface convection, and by gravitational redshifts. A parallel program (Gullberg & Dravins 1997) is analyzing high-precision spectroscopic radial velocities for different spectral lines in these stars, using the ELODIE radial-velocity instrument atHaute-Provence.

Sign in / Sign up

Export Citation Format

Share Document