on the pms star hbc 498 and its associated nebulous stars1
... star taken by us (see Fig. 2). We conclude that stars HBC 498 and DL Ori/G2 have Hα mildly in emission or filled-in with emission (W(Hα) ≤ 10 Å), while the equivalent widths of the Hα emission line of HBC 495 and HBC 496 are comparable with those of CTTS’s. The equivalent widths of the photospheric ...
... star taken by us (see Fig. 2). We conclude that stars HBC 498 and DL Ori/G2 have Hα mildly in emission or filled-in with emission (W(Hα) ≤ 10 Å), while the equivalent widths of the Hα emission line of HBC 495 and HBC 496 are comparable with those of CTTS’s. The equivalent widths of the photospheric ...
A spectroscopic investigation of the O
... Results. We confirm the binarity for four objects: HD 193443, HD 228989, HD 229234, and HD 194649. We derive for the first time the orbital solutions of three systems, and we confirm the values of the fourth, showing that these four systems all have orbital periods shorter than 10 days. Besides thes ...
... Results. We confirm the binarity for four objects: HD 193443, HD 228989, HD 229234, and HD 194649. We derive for the first time the orbital solutions of three systems, and we confirm the values of the fourth, showing that these four systems all have orbital periods shorter than 10 days. Besides thes ...
I. Constellations
... A. A constellation is typically thought of as a collection of ____stars____ named after ____an animal____, ____a person____ or ___ an object ____. B. In modern astronomy, a constellation is defined as a specific ____area____ of the sky as determined by the International Astronomical Union (IAU). C. ...
... A. A constellation is typically thought of as a collection of ____stars____ named after ____an animal____, ____a person____ or ___ an object ____. B. In modern astronomy, a constellation is defined as a specific ____area____ of the sky as determined by the International Astronomical Union (IAU). C. ...
Evolution of galaxy morphology - Lecture 1 - NCRA-TIFR
... Where e refers to effective values and n is the Sérsic index. For n=4 it becomes the de Vaucouleurs function; for n=1 an exponential, and when n=0.5, a Gaussian! For values in the range 1-4, approximately, it describes bulges in late-type spiral galaxies (or pseudo-bulges) to bulges in early-type sp ...
... Where e refers to effective values and n is the Sérsic index. For n=4 it becomes the de Vaucouleurs function; for n=1 an exponential, and when n=0.5, a Gaussian! For values in the range 1-4, approximately, it describes bulges in late-type spiral galaxies (or pseudo-bulges) to bulges in early-type sp ...
- National Optical Astronomy Observatory
... translation stage and the number of spectral frame to collect. (Take into account that one slit width is about half an arcsecond and the diffraction limit of the telescope at 5 microns is ~0.8 arcseconds. Spatially sampling at ~0.4 arcseconds would then be about right under good seeing.) ! Input sca ...
... translation stage and the number of spectral frame to collect. (Take into account that one slit width is about half an arcsecond and the diffraction limit of the telescope at 5 microns is ~0.8 arcseconds. Spatially sampling at ~0.4 arcseconds would then be about right under good seeing.) ! Input sca ...
A Digital Spectral Classification Atlas
... For the DSO spectra, two spectral resolutions are used in this atlas. Most of the illustrations use spectra obtained with the 1200g/mm grating, which gives a spectral resolution of 1.8Å/2 pixels and a spectral range of 3800Å – 4600Å, but some illustrations, especially those of the later-type star ...
... For the DSO spectra, two spectral resolutions are used in this atlas. Most of the illustrations use spectra obtained with the 1200g/mm grating, which gives a spectral resolution of 1.8Å/2 pixels and a spectral range of 3800Å – 4600Å, but some illustrations, especially those of the later-type star ...
On the Spiral Structure of the Milky Way Galaxy
... Data on other galaxies are known to demonstrate that HI superclouds, giant molecular clouds (GMCs) and young stars genetically related to them, and HII regions are located along spiral arms and often concentrated in giant star and gas complexes [5, 6]. The complexes in the spiral arms related to the ...
... Data on other galaxies are known to demonstrate that HI superclouds, giant molecular clouds (GMCs) and young stars genetically related to them, and HII regions are located along spiral arms and often concentrated in giant star and gas complexes [5, 6]. The complexes in the spiral arms related to the ...
Early-type stars in the core of the young open cluster Westerlund 2
... is dominated by strong and broad H Balmer lines. Weak absorption lines of He λλ 4388, 4471, Mg λ 4481 and Si λ 4552 are also seen. The He λ 4471/Mg λ 4481 intensity ratio indicates a spectral type B8-A0. The appearance of some weak metallic lines favours an A0 classification, whilst ...
... is dominated by strong and broad H Balmer lines. Weak absorption lines of He λλ 4388, 4471, Mg λ 4481 and Si λ 4552 are also seen. The He λ 4471/Mg λ 4481 intensity ratio indicates a spectral type B8-A0. The appearance of some weak metallic lines favours an A0 classification, whilst ...
ROSAT Ian R. Stevens* and David K. Strickland*
... superimposed on the Digitized Sky Survey image. The X-ray contours are from the longer 6.2-ks observation only. As noted by Turner et al. (1993), there are several point sources in the vicinity of the nucleus of NGC 1365. In addition to a strong central point source there is also low-surface-brightn ...
... superimposed on the Digitized Sky Survey image. The X-ray contours are from the longer 6.2-ks observation only. As noted by Turner et al. (1993), there are several point sources in the vicinity of the nucleus of NGC 1365. In addition to a strong central point source there is also low-surface-brightn ...
lecture course
... names. Names are usually taken from the following catalogs (if a galaxy appears in more than one catalog, the name from the first-listed is usually adopted). Messier or M (bright local objects, many are star clusters) NGC (New Galaxy Catalog, about 8000 objects, many are star clusters) Zwicky ...
... names. Names are usually taken from the following catalogs (if a galaxy appears in more than one catalog, the name from the first-listed is usually adopted). Messier or M (bright local objects, many are star clusters) NGC (New Galaxy Catalog, about 8000 objects, many are star clusters) Zwicky ...
Selected observation targets at a glance per constellation
... yrs, one of the largest stars known, with an apparent diameter between 0.043 and 0.056”, part of two prominent winter asterisms: the Winter Triangle and the Winter Hexagon.The other two stars forming the Winter Triangle, also known as the Great Southern Triangle, are Sirius and Procyon, same stars a ...
... yrs, one of the largest stars known, with an apparent diameter between 0.043 and 0.056”, part of two prominent winter asterisms: the Winter Triangle and the Winter Hexagon.The other two stars forming the Winter Triangle, also known as the Great Southern Triangle, are Sirius and Procyon, same stars a ...
A Comet-Hunter`s Legacy -
... fuzzy patch in Taurus which looked, in a small telescope, just like a comet, but did not move among the stars from night to night, as comets do. This fuzzy patch had already been discovered by John Bevis, in 1731, but became most famous as M1, the first item in a list which Messier began to compile, ...
... fuzzy patch in Taurus which looked, in a small telescope, just like a comet, but did not move among the stars from night to night, as comets do. This fuzzy patch had already been discovered by John Bevis, in 1731, but became most famous as M1, the first item in a list which Messier began to compile, ...
A Zoo of Galaxies - Cambridge University Press
... The variety of different galaxies observed in the sky naturally caused people to wonder what they were. The scientific arguments surrounding this question at the start of the 20th century, are best represented perhaps, by the public debate held in 1920 between Heber Curtis and Harlow Shapley. Many oth ...
... The variety of different galaxies observed in the sky naturally caused people to wonder what they were. The scientific arguments surrounding this question at the start of the 20th century, are best represented perhaps, by the public debate held in 1920 between Heber Curtis and Harlow Shapley. Many oth ...
Wolf-Rayet Stars
... tendency to refer to WN stars of classes 2 to 5 as early type (WNE) and classes 6 to 9 as late type (WNL). Similarly WC4-6 stars are designated as WCE, while WC7-9 stars are designated as WCL. Although there are important exceptions, WNE stars generally show no evidence for H emission while H emissi ...
... tendency to refer to WN stars of classes 2 to 5 as early type (WNE) and classes 6 to 9 as late type (WNL). Similarly WC4-6 stars are designated as WCE, while WC7-9 stars are designated as WCL. Although there are important exceptions, WNE stars generally show no evidence for H emission while H emissi ...
Building galaxies Hunt, Leslie Kipp
... conjectured that “There may be innumerable spheres of this kind or starry heavens in the finite universe”. Thomas Wright of Durham, England, a few years after, interpreted the observations at that time of “the many cloudy Spots, just perceivable by us, as far without our starry Regions”. This idea w ...
... conjectured that “There may be innumerable spheres of this kind or starry heavens in the finite universe”. Thomas Wright of Durham, England, a few years after, interpreted the observations at that time of “the many cloudy Spots, just perceivable by us, as far without our starry Regions”. This idea w ...
A catalogue of the Chandra Deep Field South with multi
... MIDAS package. A WFI image processing pipeline was developed by Wolf et al. (2001) and makes intensive use of programmes developed by K. Meisenheimer, H.-J. Röser and H. Hippelein for the Calar Alto Deep Imaging Survey (CADIS). The pipeline performes basic image reduction and standard operations of ...
... MIDAS package. A WFI image processing pipeline was developed by Wolf et al. (2001) and makes intensive use of programmes developed by K. Meisenheimer, H.-J. Röser and H. Hippelein for the Calar Alto Deep Imaging Survey (CADIS). The pipeline performes basic image reduction and standard operations of ...
Practical cosmology with the Local Volume galaxies
... presents the distribution of nearby galaxies in Supergalactic coordinates. The vector extending from our location indicates the Local Group motion (320 km/s) with respect to galaxies within 3000 km/s as the vector sum of two components: 260 km/s away from the Local Void and 180 km/s toward the Virgo ...
... presents the distribution of nearby galaxies in Supergalactic coordinates. The vector extending from our location indicates the Local Group motion (320 km/s) with respect to galaxies within 3000 km/s as the vector sum of two components: 260 km/s away from the Local Void and 180 km/s toward the Virgo ...
Carbon-enhanced metal-poor stars in dwarf galaxies
... [Fe/H]≤ −3 have been observed, and 10 of them are found to be CEMP-no stars. This gives FCEMP (< −3) ≈ 42%. However, when we consider individual dwarf galaxies, the fractions are highly variable. The carbon measurements in the least luminous ultra-faint dwarf galaxies, log(L/L# ) < 4.0 (shown in Fig ...
... [Fe/H]≤ −3 have been observed, and 10 of them are found to be CEMP-no stars. This gives FCEMP (< −3) ≈ 42%. However, when we consider individual dwarf galaxies, the fractions are highly variable. The carbon measurements in the least luminous ultra-faint dwarf galaxies, log(L/L# ) < 4.0 (shown in Fig ...
Nebulae.The Lagoon and Dumbbell Nebulae
... a remnant of a dying star which is approximately 2 times smaller than the Sun. The star is hot and blue with temperature of 85000K (Most of these stars usually turn into red giants. They lose their mass by ejection of the outer gas layers. These layers expand in space, forming a temporary wrap aroun ...
... a remnant of a dying star which is approximately 2 times smaller than the Sun. The star is hot and blue with temperature of 85000K (Most of these stars usually turn into red giants. They lose their mass by ejection of the outer gas layers. These layers expand in space, forming a temporary wrap aroun ...
Do We Know of Any Maunder Minimum Stars?
... well-studied. do Nascimento et al. (2003) showed that evolved stars with B −V > 0.55 have lower activity levels than their main sequence counterparts, leading to the possibility of confusion between slightly evolved stars and stars in a Maunder Minimum-like state. ...
... well-studied. do Nascimento et al. (2003) showed that evolved stars with B −V > 0.55 have lower activity levels than their main sequence counterparts, leading to the possibility of confusion between slightly evolved stars and stars in a Maunder Minimum-like state. ...
Hot Horizontal Branch Stars in the Galactic Bulge. I
... a metallicity 3 – 4 times solar (Peterson & Green 1998). In addition to two cooler BHB (or blue straggler) members, the cluster harbors four or five sdB/O stars (Liebert, Saffer, & Green 1994) whose membership is likely given their spatial concentration towards the cluster center (Kaluzny & Udalski ...
... a metallicity 3 – 4 times solar (Peterson & Green 1998). In addition to two cooler BHB (or blue straggler) members, the cluster harbors four or five sdB/O stars (Liebert, Saffer, & Green 1994) whose membership is likely given their spatial concentration towards the cluster center (Kaluzny & Udalski ...
A Zoo of Galaxies - Portsmouth Research Portal
... changed a lot over the last century or two is a bit of an understatement. In 1845 the state of the art picture of an external galaxy, was an image of M51, or the Whirlpool galaxy drawn by William Parsons, Third Earl of Rosse (1800-1867), looking through what at the time was the largest telescope in ...
... changed a lot over the last century or two is a bit of an understatement. In 1845 the state of the art picture of an external galaxy, was an image of M51, or the Whirlpool galaxy drawn by William Parsons, Third Earl of Rosse (1800-1867), looking through what at the time was the largest telescope in ...
A Zoo of Galaxies
... changed a lot over the last century or two is a bit of an understatement. In 1845 the state of the art picture of an external galaxy, was an image of M51, or the Whirlpool galaxy drawn by William Parsons, Third Earl of Rosse (1800-1867), looking through what at the time was the largest telescope in ...
... changed a lot over the last century or two is a bit of an understatement. In 1845 the state of the art picture of an external galaxy, was an image of M51, or the Whirlpool galaxy drawn by William Parsons, Third Earl of Rosse (1800-1867), looking through what at the time was the largest telescope in ...
Measuring distances to the edge of the local group
... NOAO Observing Proposal Standard Proposal ...
... NOAO Observing Proposal Standard Proposal ...
Article PDF - IOPscience
... More than seventy years ago, Oosterhoff (1939) discovered that the Milky Way (MW) globular clusters (GCs) could be divided into two groups according to the mean period of their RR Lyrae (RRL) stars. The two groups were later christened according to his name, Oosterhoff type I (Oo I) and Oosterhoff t ...
... More than seventy years ago, Oosterhoff (1939) discovered that the Milky Way (MW) globular clusters (GCs) could be divided into two groups according to the mean period of their RR Lyrae (RRL) stars. The two groups were later christened according to his name, Oosterhoff type I (Oo I) and Oosterhoff t ...
Aries (constellation)
Aries is one of the constellations of the zodiac. It is located in the northern celestial hemisphere between Pisces to the west and Taurus to the east. The name Aries is Latin for ram, and its symbol is 20px (Unicode ♈), representing a ram's horns. It is one of the 48 constellations described by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. It is a mid-sized constellation, ranking 39th overall size, with an area of 441 square degrees (1.1% of the celestial sphere).Although Aries came to represent specifically the ram whose fleece became the Golden Fleece of Ancient Greek mythology, it has represented a ram since late Babylonian times. Before that, the stars of Aries formed a farmhand. Different cultures have incorporated the stars of Aries into different constellations including twin inspectors in China and a porpoise in the Marshall Islands. Aries is a relatively dim constellation, possessing only four bright stars: Hamal (Alpha Arietis, second magnitude), Sheratan (Beta Arietis, third magnitude), Mesarthim (Gamma Arietis, fourth magnitude), and 41 Arietis (also fourth magnitude). The few deep-sky objects within the constellation are quite faint and include several pairs of interacting galaxies. Several meteor showers appear to radiate from Aries, including the Daytime Arietids and the Epsilon Arietids.