scholarly journals astrosource: automating optical astronomy measurement, calibration and analysis for variable stellar sources from provided photometry

2021 ◽  
Vol 6 (58) ◽  
pp. 2641
Author(s):  
Michael Fitzgerald ◽  
Edward Gomez ◽  
Saeed Salimpour ◽  
Joe Singleton ◽  
Ridlo Wibowo
1998 ◽  
Vol 11 (1) ◽  
pp. 423-424
Author(s):  
Motohide Tamura ◽  
Yoichi Itoh ◽  
Yumiko Oasa ◽  
Alan Tokunaga ◽  
Koji Sugitani

Abstract In order to tackle the problems of low-mass end of the initial mass function (IMF) in star-forming regions and the formation mechanisms of brown dwarfs, we have conducted deep infrared surveys of nearby molecular clouds. We have found a significant population of very low-luminosity sources with IR excesses in the Taurus cloud and the Chamaeleon cloud core regions whose extinction corrected J magnitudes are 3 to 8 mag fainter than those of typical T Tauri stars in the same cloud. Some of them are associated with even fainter companions. Follow-up IR spectroscopy has confirmed for the selected sources that their photospheric temperature is around 2000 to 3000 K. Thus, these very low-luminosity young stellar sources are most likely very low-mass T Tauri stars, and some of them might even be young brown dwarfs.


Nature ◽  
1967 ◽  
Vol 213 (5080) ◽  
pp. 977-980 ◽  
Author(s):  
K. I. KELLERMANN ◽  
I. I. K. PAULINY-TOTH
Keyword(s):  

1998 ◽  
Vol 42 (2) ◽  
pp. 125-128 ◽  
Author(s):  
M.A. Hendry ◽  
I.J. Coleman ◽  
N. Gray ◽  
A.M. Newsam ◽  
J.F.L. Simmons
Keyword(s):  

Author(s):  
Francesco Paresce ◽  
Mark Clampin ◽  
Colin Cox ◽  
Jim Crocker ◽  
Mark Rafal ◽  
...  
Keyword(s):  

Author(s):  
S. P. Moran ◽  
T. F. Heinsheimer ◽  
T. L. Stocker ◽  
S. P. S. Anand ◽  
R. D. Chapman ◽  
...  

1987 ◽  
Vol 115 ◽  
pp. 71-74
Author(s):  
H. Zinnecker ◽  
A. Chelli ◽  
C. Perrier

High spatial resolution infrared observations (mostly at L, some at K) of several young stars in the ρ Oph dark cloud were obtained with the specklegraph at the ESO 3.6m telescope in Chile in July 1985. Sources included EL29, EL21, EL14 and EL9 (Elias 1978, Table 2), and were all measured in two orthogonal directions, W-E (PA=90°) and N-S (PA=180°). Here we shall present visibility functions for EL29 and EL21 and indicate the spatial structure and dimension of these objects. We refer to Elias (1978, p.468/69) for earlier studies of EL29 and EL21.


1967 ◽  
Vol 1 (1) ◽  
pp. 7-7 ◽  
Author(s):  
J. B. Oke ◽  
Wallace L. W. Sargent

The small group of known Seyfert galaxies (Seyfert 1943) is of interest because it is clear that some violent activity is occurring in the nucleus, and some of the properties suggest a relationship with quasi-stellar sources. The spectrum of a Seyfert galaxy consists of strong, often very broad, emission lines superposed on a continuous spectrum which in some cases shows no absorption-line features. Two of the galaxies, NGC 1068 and 1275, are radio galaxies and the latter is known to be variable at radio frequencies (Dent 1966).


1990 ◽  
Vol 123 ◽  
pp. 49-57
Author(s):  
J.B. Holberg

AbstractThe instrumental characteristics, observational capabilities and scientific results of the Voyager 1 and 2 ultraviolet spectrometers are reviewed. These instruments provide current and ongoing access to low resolution spectra for a wide variety of astronomical sources in the 500 to 1700 Å band. Observations of the brightest OB stars and hot subluminous stars as faint as V = 15 mag. are possible. In the EUV, at wavelengths shortward of 900 Å, several new sources have been detected and a host of potential sources ruled out. In the Far UV, particularly at wavelengths between 900 and 1200 Å, Voyager is capable of observing a wide range of stellar and non-stellar sources. Such observations can often provide a valuable complement to IUE and other data sets at longer wavelengths. The Voyager spectrometers have proved remarkably stable photon counting instruments, capable of extremely long integration times. The long integration times, relatively large field of view, and location in the outer solar system also provide an ideal platform for observations of sources of faint diffuse emission, such as nebulae and the general sky background.


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