here
... eastern sky prior to sunrise for northern hemisphere observers and will be more easily visible at the end of the month, when it brightens to magnitude -0.3. During May, Venus shines prominently in the dawn sky. It decreases in angular diameter from 37.8 arc minutes to 24.8 arc minutes but increases ...
... eastern sky prior to sunrise for northern hemisphere observers and will be more easily visible at the end of the month, when it brightens to magnitude -0.3. During May, Venus shines prominently in the dawn sky. It decreases in angular diameter from 37.8 arc minutes to 24.8 arc minutes but increases ...
Carbon, nitrogen and oxygen abundances in
... Fundamental parameters and the carbon, nitrogen and oxygen abundances are determined for 22 B-type stars with distances d ≤ 600 pc and slow rotation (v sin i ≤ 66 km s−1 ). The stars are selected according to their effective temperatures Teff and surface gravities log g, namely: Teff is between 15 3 ...
... Fundamental parameters and the carbon, nitrogen and oxygen abundances are determined for 22 B-type stars with distances d ≤ 600 pc and slow rotation (v sin i ≤ 66 km s−1 ). The stars are selected according to their effective temperatures Teff and surface gravities log g, namely: Teff is between 15 3 ...
Article PDF - IOPscience
... A major problem in extragalactic astronomy is the inability to distinguish in a robust, physical, and modelindependent way how galaxy populations are physically related to each other and to their formation histories. A similar, but distinct, and also long-standing question is whether the structural ...
... A major problem in extragalactic astronomy is the inability to distinguish in a robust, physical, and modelindependent way how galaxy populations are physically related to each other and to their formation histories. A similar, but distinct, and also long-standing question is whether the structural ...
Comet Kirch in Art and Astronomy
... reached its perihelion on 8th of December 1680 (18th December) passing at a distance of 0,0062 AU (around 930000 km) from the Sun, and its closest approach to the Earth was on 20th of November (30th November N. S.) of 0,42 AU. The Kirch Comet was visible with naked eye before sunrise and after sunse ...
... reached its perihelion on 8th of December 1680 (18th December) passing at a distance of 0,0062 AU (around 930000 km) from the Sun, and its closest approach to the Earth was on 20th of November (30th November N. S.) of 0,42 AU. The Kirch Comet was visible with naked eye before sunrise and after sunse ...
- Isaac Newton Group of Telescopes
... should be undergoing gravitational contraction, radiating much more energy than in later stages of their evolution. More massive brown dwarfs in the Pleiades should be detectable in sufficiently deep surveys. After only 0.3% of the clusters area had been explored using IAC80 telescope at Teide Obse ...
... should be undergoing gravitational contraction, radiating much more energy than in later stages of their evolution. More massive brown dwarfs in the Pleiades should be detectable in sufficiently deep surveys. After only 0.3% of the clusters area had been explored using IAC80 telescope at Teide Obse ...
The evolution of close binaries with white dwarf components
... (M . 8M⊙ ) the stellar radius increases by a factor of about 10-100 compared to the mainsequence radius. When the density and the temperature in the core become sufficiently high, core helium burning is ignited and carbon and oxygen are formed. For a low mass star of M . 2M⊙ , helium ignition occurs u ...
... (M . 8M⊙ ) the stellar radius increases by a factor of about 10-100 compared to the mainsequence radius. When the density and the temperature in the core become sufficiently high, core helium burning is ignited and carbon and oxygen are formed. For a low mass star of M . 2M⊙ , helium ignition occurs u ...
Chapter 5 The Evolutionary Paths Of Nearby Galaxies
... of a small random sample of the massive late-types residing across the blue cloud and transition region, demonstrating the visible reddening at optical wavelengths. Therefore, in the rest of this section I focus on the properties of late-type galaxies to try to understand the mechanisms behind the q ...
... of a small random sample of the massive late-types residing across the blue cloud and transition region, demonstrating the visible reddening at optical wavelengths. Therefore, in the rest of this section I focus on the properties of late-type galaxies to try to understand the mechanisms behind the q ...
Search For Gas Giants Around Late-m Dwarfs - STARS
... temperature relationship. Our calculations show effective temperatures in the range of 3000 2300 K. Comparison of these values with models in literature show a good agreement. The absolute radial and rotational velocities of our targets were also calculated. Values of rotational velocities indicate ...
... temperature relationship. Our calculations show effective temperatures in the range of 3000 2300 K. Comparison of these values with models in literature show a good agreement. The absolute radial and rotational velocities of our targets were also calculated. Values of rotational velocities indicate ...
Star Formation in the Milky Way and Nearby Galaxies Further
... et al. 2008; Heiderman et al. 2010; Lada, Lombardi & Alves 2010), a volume-density criterion (typically n > 104 cm−3 ) (e.g., Lada 1992), and detection of a line from certain molecules, such as HCN. The surface- and volume-density criteria roughly agree in nearby clouds (Lada et al. 2012), but they ...
... et al. 2008; Heiderman et al. 2010; Lada, Lombardi & Alves 2010), a volume-density criterion (typically n > 104 cm−3 ) (e.g., Lada 1992), and detection of a line from certain molecules, such as HCN. The surface- and volume-density criteria roughly agree in nearby clouds (Lada et al. 2012), but they ...
Abstract The Star Formation History of Low Surface Brightness Galaxies
... poorly constrained. These objects tend to be rather blue, contradicting the initial impression that they may simply be faded remnants of higher surface brightness galaxies whose star formation has finished. Other scenarios span a broad range: a young mean age, less dust, a lower metallicity, perhaps ...
... poorly constrained. These objects tend to be rather blue, contradicting the initial impression that they may simply be faded remnants of higher surface brightness galaxies whose star formation has finished. Other scenarios span a broad range: a young mean age, less dust, a lower metallicity, perhaps ...
Tuomas Kangas
... Supernova (SN) events have been observed throughout millennia. These transient events were sometimes bright enough to be observed with the naked eye. The earliest recorded SN, observed by the ancient Chinese, dates back to the year 185 – and, using the modern naming convention, is thus known as SN 1 ...
... Supernova (SN) events have been observed throughout millennia. These transient events were sometimes bright enough to be observed with the naked eye. The earliest recorded SN, observed by the ancient Chinese, dates back to the year 185 – and, using the modern naming convention, is thus known as SN 1 ...
Gaia 1 and 2. A pair of new satellites of the Galaxy
... Gaia-detected sources is indeed very prominent (top left and top middle panels). Note a white patch corresponding to a dearth of Gaia sources near the centre of the over-density. This is the location of Sirius, where Gaia struggles to detect genuine stars3 . The area affected by Sirius is much large ...
... Gaia-detected sources is indeed very prominent (top left and top middle panels). Note a white patch corresponding to a dearth of Gaia sources near the centre of the over-density. This is the location of Sirius, where Gaia struggles to detect genuine stars3 . The area affected by Sirius is much large ...
harlow shapley - National Academy of Sciences
... 60" Reflector. Shapley followed Bailey's advice, and the rest is history. It seems now perfectly natural that, back in 1914, someone would have undertaken the study of variable stars in globular clusters, especially RR Lyrae variable stars with periods in the range mostly between half a day and one ...
... 60" Reflector. Shapley followed Bailey's advice, and the rest is history. It seems now perfectly natural that, back in 1914, someone would have undertaken the study of variable stars in globular clusters, especially RR Lyrae variable stars with periods in the range mostly between half a day and one ...
Clusters: age scales for stellar physics
... were identified as the culprit (Bethe 1939). This is an important lesson: pieces which do not match in this enormous puzzle (our understanding of natural phenomena) do provide, eventually, very interesting hints for new avenues and discoveries. Age and related issues belong to this category. In the ...
... were identified as the culprit (Bethe 1939). This is an important lesson: pieces which do not match in this enormous puzzle (our understanding of natural phenomena) do provide, eventually, very interesting hints for new avenues and discoveries. Age and related issues belong to this category. In the ...
the stebbins galaxy: the origins of interstellar medium studies
... the Galaxy, shows the Sun to be far from that center. 2) The measured distances to globular clusters show the Galaxy to be about 70,000 parsecs (200,000 light-years or so) in diameter (Shapley, 1930a: 221). This is about twice the modern figure for the luminous Galaxy. In his earlier publications, a ...
... the Galaxy, shows the Sun to be far from that center. 2) The measured distances to globular clusters show the Galaxy to be about 70,000 parsecs (200,000 light-years or so) in diameter (Shapley, 1930a: 221). This is about twice the modern figure for the luminous Galaxy. In his earlier publications, a ...
The Formation of Population III Stars in Gas Accretion Stage: Effects
... 2003; Yoshida et al. 2006; Yoshida et al. 2008). Cosmological simulations have shown that the first collapsed objects had a baryonic mass of ∼ 103 − 104 M⊙ and a temperature of ∼ 200 − 300 K (e.g., Bromm et al. 2002). Until several years ago, it was thought that only a single massive star with a mass ...
... 2003; Yoshida et al. 2006; Yoshida et al. 2008). Cosmological simulations have shown that the first collapsed objects had a baryonic mass of ∼ 103 − 104 M⊙ and a temperature of ∼ 200 − 300 K (e.g., Bromm et al. 2002). Until several years ago, it was thought that only a single massive star with a mass ...
Jul y 10-12,
... A handful of Galactic High Mass X-ray Binaries have been observed to emit radiation at very high energies (MeV-TeV), dubbed gamma-ray binaries. This poster will review the importance of multiwavelength observations for understanding two of these systems, HD 259440 and LS 5039. For HD 259440, detecti ...
... A handful of Galactic High Mass X-ray Binaries have been observed to emit radiation at very high energies (MeV-TeV), dubbed gamma-ray binaries. This poster will review the importance of multiwavelength observations for understanding two of these systems, HD 259440 and LS 5039. For HD 259440, detecti ...
Colour-magnitude diagrams of the post
... Abstract. We present photometry of the globular clusters NGC 6256 in V , I, NGC 6717, NGC 6256 in V , I, and NGC 6717 in B, V , obtaining cluster parameters. NGC 6256 has a post core-collapse structure, while such feature is suspected for NGC 6717. Both clusters are projected on the bulge. From the ...
... Abstract. We present photometry of the globular clusters NGC 6256 in V , I, NGC 6717, NGC 6256 in V , I, and NGC 6717 in B, V , obtaining cluster parameters. NGC 6256 has a post core-collapse structure, while such feature is suspected for NGC 6717. Both clusters are projected on the bulge. From the ...
Stellar Populations of Dwarf Elliptical Galaxies: UBVRI Photometry
... UBVRI images of 16 dwarf elliptical galaxies in the Virgo Cluster were obtained with the VATT 1.8m on 2003 March 29-31. The telescope was equipped with CCD26, a thinned Loral 3 2048 × 2048 CCD with 15µm pixels. CCD26 has a read noise of 5.7 e− and a gain of 1.9 e− per ADU was used. On-chip binning o ...
... UBVRI images of 16 dwarf elliptical galaxies in the Virgo Cluster were obtained with the VATT 1.8m on 2003 March 29-31. The telescope was equipped with CCD26, a thinned Loral 3 2048 × 2048 CCD with 15µm pixels. CCD26 has a read noise of 5.7 e− and a gain of 1.9 e− per ADU was used. On-chip binning o ...
Lyra
Lyra (/ˈlaɪərə/; Latin for lyre, from Greek λύρα) is a small constellation. It is one of 48 listed by the 2nd century astronomer Ptolemy, and is one of the 88 constellations recognized by the International Astronomical Union. Lyra was often represented on star maps as a vulture or an eagle carrying a lyre, and hence sometimes referred to as Aquila Cadens or Vultur Cadens. Beginning at the north, Lyra is bordered by Draco, Hercules, Vulpecula, and Cygnus. Lyra is visible from the northern hemisphere from spring through autumn, and nearly overhead, in temperate latitudes, during the summer months. From the southern hemisphere, it is visible low in the northern sky during the winter months.The lucida or brightest star—and one of the brightest stars in the sky—is the white main sequence star Vega, a corner of the Summer Triangle. Beta Lyrae is the prototype of a class of stars known as Beta Lyrae variables, binary stars so close to each other that they become egg-shaped and material flows from one to the other. Epsilon Lyrae, known informally as the Double Double, is a complex multiple star system. Lyra also hosts the Ring Nebula, the second-discovered and best-known planetary nebula.