WSN 42 (2016) 132-142
... Life cycles of stars: stars are born, millions or billions of years shine and then die. Each star has a multi-stage life cycle during which the size and its temperature varies greatly. The mass of each star (the amount of matter in the star) main determinant of long-lived stars, and how it is evolvi ...
... Life cycles of stars: stars are born, millions or billions of years shine and then die. Each star has a multi-stage life cycle during which the size and its temperature varies greatly. The mass of each star (the amount of matter in the star) main determinant of long-lived stars, and how it is evolvi ...
Stars and Light
... bright they looked to his eye. • Herschel (1800s) first measured the brightness of stars quantitatively and matched his measurements onto Ptolemy’s magnitude groups and assigned a number for the magnitude of each star. ...
... bright they looked to his eye. • Herschel (1800s) first measured the brightness of stars quantitatively and matched his measurements onto Ptolemy’s magnitude groups and assigned a number for the magnitude of each star. ...
Is Draco II one of the faintest dwarf galaxies? First study from Keck
... region is typical 30/8 at iP1 = 18.0/20.0. For a cold stellar system like Dra II, it is particularly important to assess the level of systematics on the measured velocity uncertainties. DEIMOS is known to yield a small level of systematics that cannot be entirely explained from properly tracking the ...
... region is typical 30/8 at iP1 = 18.0/20.0. For a cold stellar system like Dra II, it is particularly important to assess the level of systematics on the measured velocity uncertainties. DEIMOS is known to yield a small level of systematics that cannot be entirely explained from properly tracking the ...
Magnitude Scales and Photometric Systems
... for very hot stars, was obtained by using a common violet glass. In retrospect, these choices should have been based more on astrophysics and less on glass availability, but so much work has been done in this UBV system that the weight of history ensured its continuation. Intercomparison of much of ...
... for very hot stars, was obtained by using a common violet glass. In retrospect, these choices should have been based more on astrophysics and less on glass availability, but so much work has been done in this UBV system that the weight of history ensured its continuation. Intercomparison of much of ...
HW #02 Solutions
... Astronomy Notes. Note: There are additional problems with solutions listed below ...
... Astronomy Notes. Note: There are additional problems with solutions listed below ...
AST 301 Introduction to Astronomy - University of Texas Astronomy
... Spica has a luminosity 10,000 times that of the Sun. How does the amount of hydrogen it fuses in a year compare to the amount the Sun fuses? Spica has a mass of 14 Msun, and like the Sun it can fuse 1/10 of its hydrogen while on the main sequence. How does its main sequence lifetime compare to the S ...
... Spica has a luminosity 10,000 times that of the Sun. How does the amount of hydrogen it fuses in a year compare to the amount the Sun fuses? Spica has a mass of 14 Msun, and like the Sun it can fuse 1/10 of its hydrogen while on the main sequence. How does its main sequence lifetime compare to the S ...
The Earth`s Orbital Velocity
... (the astronomical unit). In this exercise you will use actual astronomical observations (spectra) of the star Arcturus (α Boötis) to determine these values. You will also become familiar with the difficulties of making astronomical measurements and the uncertainties in the results. This lab will fol ...
... (the astronomical unit). In this exercise you will use actual astronomical observations (spectra) of the star Arcturus (α Boötis) to determine these values. You will also become familiar with the difficulties of making astronomical measurements and the uncertainties in the results. This lab will fol ...
Lec2015_22
... • In case when the half-life for beta-decay is short compared to the timescale for neutron capture then obtain stable nuclei directly or via beta-decay - s-process, where s is for slow • In case when the half-life for beta-decay is long compared to the timescale for neutron capture then obtain neutr ...
... • In case when the half-life for beta-decay is short compared to the timescale for neutron capture then obtain stable nuclei directly or via beta-decay - s-process, where s is for slow • In case when the half-life for beta-decay is long compared to the timescale for neutron capture then obtain neutr ...
Galaxies and the Universe
... Getting Distances • What about other stars? – Half of the angle that the star appears to move is called the parallax. – A star that is twice as far away as another star has half the parallax angle. No strange ``inversesquare’’ stuff to remember like gravity and flux. Nearly edge-on view of Earth’ ...
... Getting Distances • What about other stars? – Half of the angle that the star appears to move is called the parallax. – A star that is twice as far away as another star has half the parallax angle. No strange ``inversesquare’’ stuff to remember like gravity and flux. Nearly edge-on view of Earth’ ...
Basics of Astrophysics
... The speckle pattern change rapidly, if v is the speed of the wind the timescale can be roughly estimated by t = r/v where r is the size of the cell causing the speckle. With a rather ...
... The speckle pattern change rapidly, if v is the speed of the wind the timescale can be roughly estimated by t = r/v where r is the size of the cell causing the speckle. With a rather ...
The Life of a Star
... Once all fusion reactions stop, the star throws its outer layers into space, forming a planetary nebula – This leaves behind the hot dense core of the red giant. – The remaining core is called a white dwarf. Over time, the white dwarf cools off and becomes a black dwarf. ...
... Once all fusion reactions stop, the star throws its outer layers into space, forming a planetary nebula – This leaves behind the hot dense core of the red giant. – The remaining core is called a white dwarf. Over time, the white dwarf cools off and becomes a black dwarf. ...
Lecture 8a Star Formation 10/15/2014
... – Ratio of Mass and Radius is almost linear (only changes factor of 3 within 2.5 orders of magnitude of M. PHYS 162 Lecture 8a ...
... – Ratio of Mass and Radius is almost linear (only changes factor of 3 within 2.5 orders of magnitude of M. PHYS 162 Lecture 8a ...
ppt
... s (m/s) = Constant × (S/N)–1 R–3/2 (Dl)–1/2 s: error R: spectral resolving power S/N: signal to noise ratio Dl : wavelength coverage of spectrograph in Angstroms For R=110.000, S/N=150, Dl=2000 Å, s = 2 m/s C ≈ 2.4 × 1011 For a given instrument you can take its actual performance with real observati ...
... s (m/s) = Constant × (S/N)–1 R–3/2 (Dl)–1/2 s: error R: spectral resolving power S/N: signal to noise ratio Dl : wavelength coverage of spectrograph in Angstroms For R=110.000, S/N=150, Dl=2000 Å, s = 2 m/s C ≈ 2.4 × 1011 For a given instrument you can take its actual performance with real observati ...
the May 2017 Newsletter!
... Jupiter was the only planet visible, quite high up in the east. All four Galilean moons were visible early on, with Io close in to the west of Jupiter. Not long after observing started, Io disappeared into occultation i.e it moved into Jupiter’s shadow. Although the disappearance was not observed, i ...
... Jupiter was the only planet visible, quite high up in the east. All four Galilean moons were visible early on, with Io close in to the west of Jupiter. Not long after observing started, Io disappeared into occultation i.e it moved into Jupiter’s shadow. Although the disappearance was not observed, i ...
Lec09_ch11_lifecycleofstars
... – More massive stars live shorter lives because the gravitational force creates higher temperatures and greater pressures which accelerate the pace of nuclear fusion in their cores ...
... – More massive stars live shorter lives because the gravitational force creates higher temperatures and greater pressures which accelerate the pace of nuclear fusion in their cores ...
Hipparcos
Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial objects on the sky. This permitted the accurate determination of proper motions and parallaxes of stars, allowing a determination of their distance and tangential velocity. When combined with radial-velocity measurements from spectroscopy, this pinpointed all six quantities needed to determine the motion of stars. The resulting Hipparcos Catalogue, a high-precision catalogue of more than 118,200 stars, was published in 1997. The lower-precision Tycho Catalogue of more than a million stars was published at the same time, while the enhanced Tycho-2 Catalogue of 2.5 million stars was published in 2000. Hipparcos ' follow-up mission, Gaia, was launched in 2013.The word ""Hipparcos"" is an acronym for High precision parallax collecting satellite and also a reference to the ancient Greek astronomer Hipparchus of Nicaea, who is noted for applications of trigonometry to astronomy and his discovery of the precession of the equinoxes.