The isotopic mixture of barium in the metal-poor
... profiles. Replacing the damping parameters calculated by Barklem et al. (2000) by the Unsöld approximation, our abundance estimate would increase by 0.04 dex. Next, we fit the profile of the Ba II 4554 Å line by changing the barium abundance, and f odd . Our ultra-high resolution spectra can easil ...
... profiles. Replacing the damping parameters calculated by Barklem et al. (2000) by the Unsöld approximation, our abundance estimate would increase by 0.04 dex. Next, we fit the profile of the Ba II 4554 Å line by changing the barium abundance, and f odd . Our ultra-high resolution spectra can easil ...
A Method of Correcting Near-Infrared Spectra for Telluric Absorption
... standard,” whose intrinsic spectrum is known, to derive a system throughput curve that can then be applied to a target object spectrum observed nearby in the sky and close in time. Since T(l) varies with air mass and on timescales of the order of several to tens of minutes (depending on the atmosphe ...
... standard,” whose intrinsic spectrum is known, to derive a system throughput curve that can then be applied to a target object spectrum observed nearby in the sky and close in time. Since T(l) varies with air mass and on timescales of the order of several to tens of minutes (depending on the atmosphe ...
Astronomers` Observing Guides
... Double and Multiple Stars Defined We begin this volume on viewing double and multiple stars by defining just what they are: two or more suns placed in close proximity to each other in the sky as seen with the unaided eye, binoculars or telescopes. With the exception of stars that just happen to lie al ...
... Double and Multiple Stars Defined We begin this volume on viewing double and multiple stars by defining just what they are: two or more suns placed in close proximity to each other in the sky as seen with the unaided eye, binoculars or telescopes. With the exception of stars that just happen to lie al ...
PHY216_lect3_2014_sub
... The Julian Day Number is calculated as follows: 1) Express the date as y m d, where y is the year, m is the month number (Jan = 1, Feb = 2, etc.), and d is the day in the month. 2) If the month is January or February, subtract 1 from the year to get a new y, and add 12 to the month to get a new m. ( ...
... The Julian Day Number is calculated as follows: 1) Express the date as y m d, where y is the year, m is the month number (Jan = 1, Feb = 2, etc.), and d is the day in the month. 2) If the month is January or February, subtract 1 from the year to get a new y, and add 12 to the month to get a new m. ( ...
Unlocking the secrets of stellar haloes using combined star counts
... by counting the number of bright halo stars (red giant branch stars, asymptotic giant branch stars and upper main sequence stars) within a certain area. The bright stars only account for a fraction of the overall halo light, which means that the star counts must be calibrated on to a surface brightn ...
... by counting the number of bright halo stars (red giant branch stars, asymptotic giant branch stars and upper main sequence stars) within a certain area. The bright stars only account for a fraction of the overall halo light, which means that the star counts must be calibrated on to a surface brightn ...
Downloaded - Royal Society Open Science
... flashes’. This value of 2.0 M represents a key transition mass; the duration and character of the mass loss changes markedly when crossing this threshold. After the core helium is exhausted, a heliumburning shell is formed. At this point, the star is said to have begun evolving on the ‘asymptotic g ...
... flashes’. This value of 2.0 M represents a key transition mass; the duration and character of the mass loss changes markedly when crossing this threshold. After the core helium is exhausted, a heliumburning shell is formed. At this point, the star is said to have begun evolving on the ‘asymptotic g ...
WILLIAM HERSCHEL AND THE `GARNET` STARS: μ CEPHEI AND
... in the zone observations made by Friedrich Wilhelm August Argelander (1799 –1875; Figure 7) at the Bonn Observatory from 1841 to 1844. The measurement was made on 11 September 1842. Argelander listed the position for 1842 and noted it as ―… very red.‖ (see Oelzen, 1852). The magnitude was estimated ...
... in the zone observations made by Friedrich Wilhelm August Argelander (1799 –1875; Figure 7) at the Bonn Observatory from 1841 to 1844. The measurement was made on 11 September 1842. Argelander listed the position for 1842 and noted it as ―… very red.‖ (see Oelzen, 1852). The magnitude was estimated ...
Magnetic cycles of Sun-like stars with different levels of coronal and
... began this program in 1965. He attached great importance to the long-standing systematic observations of cycles in the stars. Fluxes in passbands of 0.1 nm wide and centered on the CaII H&K emission cores have been monitored in 111 stars of the spectral type F2-K5 on or near main sequence on the Her ...
... began this program in 1965. He attached great importance to the long-standing systematic observations of cycles in the stars. Fluxes in passbands of 0.1 nm wide and centered on the CaII H&K emission cores have been monitored in 111 stars of the spectral type F2-K5 on or near main sequence on the Her ...
Spectral Matching for Elemental Abundances of Evolved Stars of Globular Clusters
... used to estimate the oxygen abundance of the stars, leading to a determination of whether a particular star was oxygen-rich or oxygen-poor. From this a catalogue of abundances of iron, carbon and barium of 848 giant branch stars were determined, of which 557 also had well-defined nitrogen abundances ...
... used to estimate the oxygen abundance of the stars, leading to a determination of whether a particular star was oxygen-rich or oxygen-poor. From this a catalogue of abundances of iron, carbon and barium of 848 giant branch stars were determined, of which 557 also had well-defined nitrogen abundances ...
The 2006 RBSE Journal - National Optical Astronomy Observatory
... the magnitude over a short period of time. A Polar is two stars that orbit each other and one of the stars pulls matter from the other which emits energy. This is also true with an AGN because, as material is pulled into the black hole of an AGN, some is redirected outward at a 90° angle in a jet, w ...
... the magnitude over a short period of time. A Polar is two stars that orbit each other and one of the stars pulls matter from the other which emits energy. This is also true with an AGN because, as material is pulled into the black hole of an AGN, some is redirected outward at a 90° angle in a jet, w ...
Reassessing the formation of the inner Oort cloud
... either a Hernquist or Plummer potential – and chose other parameters based on the latest observations of embedded clusters from the literature. These other parameters result in the stars being on radial orbits and the cluster collapses. Similar to previous studies, in our simulations the inner Oort ...
... either a Hernquist or Plummer potential – and chose other parameters based on the latest observations of embedded clusters from the literature. These other parameters result in the stars being on radial orbits and the cluster collapses. Similar to previous studies, in our simulations the inner Oort ...
The Habitability of Proxima Centauri b I: Evolutionary Scenarios
... and B (Johnson & Apps 2009). Recently, Hinkel & Kane (2013) completed a reanalysis of published compositional studies, rejecting the studies of Laird (1985) and Neuforge-Verheecke & Magain (1997) because they were too different from the other 5 they considered. Hinkel & Kane (2013) found the mean me ...
... and B (Johnson & Apps 2009). Recently, Hinkel & Kane (2013) completed a reanalysis of published compositional studies, rejecting the studies of Laird (1985) and Neuforge-Verheecke & Magain (1997) because they were too different from the other 5 they considered. Hinkel & Kane (2013) found the mean me ...
Discovery and spectroscopy of the young Jovian planet
... that are bright at young ages – referred to as “hot-start”. Alternatively, two-stage formation, first of a dense solid core followed by gas accretion through a shock, as likely in the case of Jupiter, can produce a range of states including lower-entropy planets that are cooler, and slightly smaller ...
... that are bright at young ages – referred to as “hot-start”. Alternatively, two-stage formation, first of a dense solid core followed by gas accretion through a shock, as likely in the case of Jupiter, can produce a range of states including lower-entropy planets that are cooler, and slightly smaller ...
CONSTELLATION PERSEUS The constellation
... Located 92.8 light-years from Earth, it varies in apparent magnitude from a minimum of 3.5 to a maximum of 2.3 over a period of 2.867 days. The star system is the prototype of a group of eclipsing binary stars named Algol variables. • Alpha Persei known as Mirfak (Arabic for elbow) is the brightest ...
... Located 92.8 light-years from Earth, it varies in apparent magnitude from a minimum of 3.5 to a maximum of 2.3 over a period of 2.867 days. The star system is the prototype of a group of eclipsing binary stars named Algol variables. • Alpha Persei known as Mirfak (Arabic for elbow) is the brightest ...
- StealthSkater
... Let's suppose we wanted to make out own map of a trip to the stars. We will limit ourselves to the 55 light-year radius covered by the detailed star catalogs. The purpose of the trip will be to search for intelligent life on planets that may be in orbit around these stars. We would want to include e ...
... Let's suppose we wanted to make out own map of a trip to the stars. We will limit ourselves to the 55 light-year radius covered by the detailed star catalogs. The purpose of the trip will be to search for intelligent life on planets that may be in orbit around these stars. We would want to include e ...
IK Pegasi
IK Pegasi (or HR 8210) is a binary star system in the constellation Pegasus. It is just luminous enough to be seen with the unaided eye, at a distance of about 150 light years from the Solar System.The primary (IK Pegasi A) is an A-type main-sequence star that displays minor pulsations in luminosity. It is categorized as a Delta Scuti variable star and it has a periodic cycle of luminosity variation that repeats itself about 22.9 times per day. Its companion (IK Pegasi B) is a massive white dwarf—a star that has evolved past the main sequence and is no longer generating energy through nuclear fusion. They orbit each other every 21.7 days with an average separation of about 31 million kilometres, or 19 million miles, or 0.21 astronomical units (AU). This is smaller than the orbit of Mercury around the Sun.IK Pegasi B is the nearest known supernova progenitor candidate. When the primary begins to evolve into a red giant, it is expected to grow to a radius where the white dwarf can accrete matter from the expanded gaseous envelope. When the white dwarf approaches the Chandrasekhar limit of 1.44 solar masses (M☉), it may explode as a Type Ia supernova.