The accretion disk paradigm for young stars
... whereas the observed excess luminosity can be greater than L in extreme CTTSs. Even though the value of a typical CTTS luminosity excess was unknown in the early 1950s, it was already clear that it was orders of magnitude larger than what the accretion of interstellar cloud gas could provide. Faced ...
... whereas the observed excess luminosity can be greater than L in extreme CTTSs. Even though the value of a typical CTTS luminosity excess was unknown in the early 1950s, it was already clear that it was orders of magnitude larger than what the accretion of interstellar cloud gas could provide. Faced ...
preprint, pdf version - LESIA
... events observed in Brazil and Chile (4 June 2011) and in Hawaii (23 June 2011). These last two events, as in 22 June 2008, were double events in which Charon and Pluto occulted the same star. In the 4 June 2011 event in particular, both occultations could be recorded at each site. The population of ...
... events observed in Brazil and Chile (4 June 2011) and in Hawaii (23 June 2011). These last two events, as in 22 June 2008, were double events in which Charon and Pluto occulted the same star. In the 4 June 2011 event in particular, both occultations could be recorded at each site. The population of ...
Chemical abundances and winds of massive stars in M31: a B
... Numerous surveys have identified OB and WR stars beyond the Magellanic Clouds e.g. Massey et al. (1986); Moffat & Shara (1987), although little quantitative analysis has been carried out to date. The only detailed studies of WolfRayet stars beyond the Magellanic Clouds have been studies of late WN s ...
... Numerous surveys have identified OB and WR stars beyond the Magellanic Clouds e.g. Massey et al. (1986); Moffat & Shara (1987), although little quantitative analysis has been carried out to date. The only detailed studies of WolfRayet stars beyond the Magellanic Clouds have been studies of late WN s ...
A COMPREHENSIVE COMPARISON OF THE SUN TO
... these conventions in Figs. 2 Y11. The solid curve and hatched area around it represents the IMF and its associated uncertainty ( Kroupa 2002). The Sun, indicated by the Sun symbol (), is more massive than 95% 2% of these stars. ...
... these conventions in Figs. 2 Y11. The solid curve and hatched area around it represents the IMF and its associated uncertainty ( Kroupa 2002). The Sun, indicated by the Sun symbol (), is more massive than 95% 2% of these stars. ...
Red supergiants and the past of Cygnus OB2
... makes them easily detectable in the near infrared, making them useful probes of star formation that occurred several tens of Myr ago. Aims. We investigate the past star formation history of Cygnus OB2, the nearest very massive OB association, using red supergiants as a probe. Our aim is to confirm t ...
... makes them easily detectable in the near infrared, making them useful probes of star formation that occurred several tens of Myr ago. Aims. We investigate the past star formation history of Cygnus OB2, the nearest very massive OB association, using red supergiants as a probe. Our aim is to confirm t ...
Chemical abundances and winds of massive stars in M31: a Btype
... their M31 target stars prevented strong constraints being placed on the exact shape of this extinction curve. We have briefly reinvestigated this issue using a slightly different procedure, following Fitzpatrick (1986) in using other B-type supergiants in the LMC as the comparison stars. We chose Sk ...
... their M31 target stars prevented strong constraints being placed on the exact shape of this extinction curve. We have briefly reinvestigated this issue using a slightly different procedure, following Fitzpatrick (1986) in using other B-type supergiants in the LMC as the comparison stars. We chose Sk ...
Galaxies - science9atsouthcarletonhs
... Galaxy Clusters • Most galaxies are not alone in the vast expanse of space, but are connected to one or more other galaxies by gravity • These collections of galaxies are known as galaxy clusters and they too appear to be organized into larger “superclusters” ...
... Galaxy Clusters • Most galaxies are not alone in the vast expanse of space, but are connected to one or more other galaxies by gravity • These collections of galaxies are known as galaxy clusters and they too appear to be organized into larger “superclusters” ...
1 Distance: A History of Parallax and Brief Introduction to Standard
... Earth was met with great skepticism. Those that were aware of the size of the Earth dismissed the notation entirely because it would mean non-stop cataclysm: continents swirling around the axis at hundreds of kilometers per hour causing continuous, extreme wind which would hypothetically cause every ...
... Earth was met with great skepticism. Those that were aware of the size of the Earth dismissed the notation entirely because it would mean non-stop cataclysm: continents swirling around the axis at hundreds of kilometers per hour causing continuous, extreme wind which would hypothetically cause every ...
Wolf-Rayet Stars
... The distribution of Population I W-R stars, which are discussed in this article, is similar to that of O stars; they are primarily located in the spiral arms of our galaxy and near H ii regions. WR masses range from an uncertain lower limit of about 5 M to in excess of 60 M , while surface tempera ...
... The distribution of Population I W-R stars, which are discussed in this article, is similar to that of O stars; they are primarily located in the spiral arms of our galaxy and near H ii regions. WR masses range from an uncertain lower limit of about 5 M to in excess of 60 M , while surface tempera ...
Comparing stars - The Open University
... than the Sun, and appears bluish-white. It has the greatest apparent visual brightness (most negative apparent visual magnitude!) of any star in the night sky. This is, as we have seen, not because it is very luminous, but because it is both fairly luminous and rather close - at 2.63 pc it's the sev ...
... than the Sun, and appears bluish-white. It has the greatest apparent visual brightness (most negative apparent visual magnitude!) of any star in the night sky. This is, as we have seen, not because it is very luminous, but because it is both fairly luminous and rather close - at 2.63 pc it's the sev ...
The first photometric analysis of the overcontact binary MQ UMa with
... cool short-period binary merging. In this paper, we focus on the high fill-out, low mass ratio overcontact binaries which are at the late evolutionary stages of the contact configuration. Photometric analysis and orbital period studies of them will provide important information for the evolution and ...
... cool short-period binary merging. In this paper, we focus on the high fill-out, low mass ratio overcontact binaries which are at the late evolutionary stages of the contact configuration. Photometric analysis and orbital period studies of them will provide important information for the evolution and ...
Galactic Nebulae
... Embedded Within clouds And only visible At infra-red Wavelengths Thick dust of Milky Way Obscures Entire region ...
... Embedded Within clouds And only visible At infra-red Wavelengths Thick dust of Milky Way Obscures Entire region ...
Star Clusters - Caltech Astronomy
... likely to be located close to the Galactic center or near the Galactic plane on the far side of the Galaxy. The globulars are substantial stellar systems. Even the smallest of them contain some 10 000 solar masses of stars and a few, such as M22 and Omega Centauri, exceed one million solar masses. A ...
... likely to be located close to the Galactic center or near the Galactic plane on the far side of the Galaxy. The globulars are substantial stellar systems. Even the smallest of them contain some 10 000 solar masses of stars and a few, such as M22 and Omega Centauri, exceed one million solar masses. A ...
Infrared Properties of Star-Forming Dwarf Galaxies. I. Dwarf Irregular
... A sample of 34 dwarf irregular galaxies (dIs) in the Local Volume, most nearer than 5 Mpc, has been imaged in the near-infrared (NIR) in J and Ks at the Canada-France-Hawaii Telescope (CFHT) in Hawaii and the Observatorio Astronómico Nacional in the Sierra San Pedro Mártir, in Mexico. Absolute mag ...
... A sample of 34 dwarf irregular galaxies (dIs) in the Local Volume, most nearer than 5 Mpc, has been imaged in the near-infrared (NIR) in J and Ks at the Canada-France-Hawaii Telescope (CFHT) in Hawaii and the Observatorio Astronómico Nacional in the Sierra San Pedro Mártir, in Mexico. Absolute mag ...
The old globular cluster system of the dIrr galaxy NGC 1427A in the
... In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxies in the frame of galaxy f ...
... In all these models, the GCSs of low-mass dwarf galaxies, the most numerous galaxy type in galaxy clusters (Sandage 2005, and references therein), are envisioned as the building blocks of the GCSs of the more massive galaxies. At present the role of the GCSs of dIrr galaxies in the frame of galaxy f ...
April 2015 Astronomy Calendar by Dave Mitsky
... Mercury, Venus, and Mars are located in the west and Jupiter in the south in the evening. At midnight, Jupiter is in the west, and Saturn is in the southeast. Saturn can be found in the southwest and Uranus and Neptune in the east in the morning sky. At midmonth, Venus sets at 11:00 p.m., Mars sets ...
... Mercury, Venus, and Mars are located in the west and Jupiter in the south in the evening. At midnight, Jupiter is in the west, and Saturn is in the southeast. Saturn can be found in the southwest and Uranus and Neptune in the east in the morning sky. At midmonth, Venus sets at 11:00 p.m., Mars sets ...
Cassiopeia (constellation)
Cassiopeia is a constellation in the northern sky, named after the vain queen Cassiopeia in Greek mythology, who boasted about her unrivalled beauty. Cassiopeia was one of the 48 constellations listed by the 2nd-century Greek astronomer Ptolemy, and it remains one of the 88 modern constellations today. It is easily recognizable due to its distinctive 'M' shape when in upper culmination but in higher northern locations when near lower culminations in spring and summer it has a 'W' shape, formed by five bright stars. It is bordered by Andromeda to the south, Perseus to the southeast, and Cepheus to the north. It is opposite the Big Dipper.In northern locations above 34ºN latitude it is visible year-round and in the (sub)tropics it can be seen at its clearest from September to early November in its characteristic 'M' shape. Even in low southern latitudes below 25ºS is can be seen low in the North.