• Study Resource
  • Explore Categories
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
11 - Visual Magnitudes Project
11 - Visual Magnitudes Project

... 11 - Visual Magnitudes Project - Charts, Stars & Magnitudes Perception & the Magnitude Scale The capabilities of the eye far surpass those of the best camera. Your eye is so sensitive it can sense a single photon (packet of light energy) or accommodate the glare of the noonday Sun, some 100 billion ...
Absolute Magnitudes of Supernovae
Absolute Magnitudes of Supernovae

... determine the absolute magnitudes of Type Ia supernovae occurring in distant galaxies. Background - During a three-week period in 1997, the Hubble Space Telescope was used to observe a supernova - an exploding star in a distant galaxy. These exploding stars appear suddenly, as they increase rapidly ...
Galaxy Questions Info
Galaxy Questions Info

... Edwin Hubble classified galaxies into four major types: spiral, barred spiral, elliptical, and irregular (see also Question 8 and Question 10). Most galaxies are spirals, barred spirals, or ellipticals. A spiral galaxy consists of a flattened disk containing spiral (pinwheel-shaped) arms, a bulge at ...
The Stars education kit - Student activities 11-20
The Stars education kit - Student activities 11-20

... Lying between the Southern Cross and the False Cross is the most luminous and massive star in our Milky Way Galaxy – Eta Carinae. It radiates five million times more brightly than the Sun and is about 120 times more massive. It sheds about two Earth masses each day in its stellar wind. If the Sun ga ...
arXiv:astro-ph/0508448v1 22 Aug 2005
arXiv:astro-ph/0508448v1 22 Aug 2005

Chapter 26: Stars, Galaxies, and the Universe Stars
Chapter 26: Stars, Galaxies, and the Universe Stars

... distant stars. Then, they wait 6 months; during this time, Earth moves from one side of its orbit around the Sun to the other side. When they look at the star again, parallax will cause the star to appear in a different position relative to more distant stars. From the size of this shift, they can c ...
Galactic Parameters from Masers with Trigonometric Parallaxes
Galactic Parameters from Masers with Trigonometric Parallaxes

... located in the range of galactocentric distances 3
Lect16-3-28-and-30-1..
Lect16-3-28-and-30-1..

The Project Gutenberg EBook of History of Astronomy, by George
The Project Gutenberg EBook of History of Astronomy, by George

Modern Telescopes and Ancient Skies
Modern Telescopes and Ancient Skies

SylTerNav\4Curr\emet
SylTerNav\4Curr\emet

... establish the appropriate time for observing planets and stars in the meridian on a given day in a given position; page 4 of 5 ...
1 Distance: A History of Parallax and Brief Introduction to Standard
1 Distance: A History of Parallax and Brief Introduction to Standard

... apparent size of the Moon should change by a factor of 2 during its phases if one were to strictly believe the wide epicycle selected by Ptolemy. Copernicus measured the diameter of the half-Moon on the night of March 9, 1497 during an eclipse of the star Aldebaran. Not even a subtle difference was ...
preprint, pdf version - LESIA
preprint, pdf version - LESIA

... a one-chord positive occultation helps to improve the ephemeris, since the apparent diameters of TNOs are smaller than 30 mas. In the case of star positions, one strategy is to select possible occultations based on the positions given in any arbitrary astrometric catalog, then perform follow-up obse ...
February - Amateur Telescope Makers of Boston
February - Amateur Telescope Makers of Boston

... This 2½ degree-long chain is comprised of some two dozen magnitude 7 to 9 stars with a 5th magnitude star at its midpoint. NGC 1502 is visible as a fuzzy patch of light at the southeastern end of the Cascade. This dazzling 8 arcminute-wide open star cluster is comprised of several dozen stars, magni ...
Chapter 15, Galaxies
Chapter 15, Galaxies

... Use independent measurements to check the luminosity of the standard candle. For example, we can use parallax measurements of the distance to main sequence stars to check measurements of distance using main-sequence fitting. If we do this for a few of them, then we can verify the assumption that the ...
History of Astronomy
History of Astronomy

... the shadow of a vertical pillar, made thousands of years before the Christian era, in summer and winter. There are other reasons why we must be tolerant of the crude notions of the ancients. The historian, wishing to give credit wherever it may be due, is met by two difficulties. Firstly, only a few ...
octl
octl

... YAG emitting 12 W average power at 532 nm with 7 nsec pulse widths at 50 Hz repetition rates. The uplink beam divergence was approximately 25 μrad. System tests validated the concept for monitoring the line of sight attenuation during laser uplink operations. Satellites were tracked through clear sk ...
Project Icarus: Astronomical Considerations Relating to the Choice
Project Icarus: Astronomical Considerations Relating to the Choice

... choice of target, not because such investigations are scientifically unimportant but because they can (largely) be conducted regardless of what the target star is chosen to be. It is true that in some directions the local interstellar medium is of more interest than others [6, 8], but this is unlike ...
doc - Eu-Hou
doc - Eu-Hou

... Since the radius is much smaller now, it rotates much faster. In fact, such neutron stars rotate once per second or even faster, up to several hundred rotations per second. The neutron star also carries a strong magnetic field, which rotates with the neutron star. Charged particles within this magne ...
Chasing the Pole — Howard L. Cohen
Chasing the Pole — Howard L. Cohen

... of almost 19 years. slight irregular motion or "nodding" called nutation with an amplitude of 9 arc sec and a period of 18.6 years. See Figure 7. This effect and the aberration of light due to the orbital motion of the Earth around the Sun, changes the mean position of celestial objects by a small a ...
Hubble - 15 Years of Discovery
Hubble - 15 Years of Discovery

... orbit the Sun out beyond Neptune. The area where these objects orbit is called the Kuiper belt, named after the Dutch astronomer Gerard Kuiper, who, in 1951, predicted the existence of a large number of icy objects in this location. In 2002 another large object was discovered in the Kuiper belt. It ...
Homologous Stellar Models and Polytropes Main Sequence Stars
Homologous Stellar Models and Polytropes Main Sequence Stars

... star in radiative equilibrium, for which the luminosity is strongly linked to the temperature gradient. For a fully convective polytropic star (n = 3/2) with H− opacity, it can be shown that Teff is related to the total mass (M ), luminosity (L) and mean molecular weight µ̄ by ...
Milky Way Bulge
Milky Way Bulge

... • Discovered in 1994 from star counts + radial velocity study of K,M giants towards Galactic Center. • ~5 x 109 M • ~17 kpc beyond GC, and currently falling into disk ...
pierrehumbert_lecture_1
pierrehumbert_lecture_1

... the atmosphere, and heat it to the point where the atmosphere can escape to space. • i.e. it’s the rocket fuel that brings molecules up to escape velocity and can launch atmosphere out of the gravity well. • Shorter wave ultraviolet drives photochemistry, and can break up heavy molecules into lighte ...
Living with a Red Dwarf - Center for Space and Habitability (CSH)
Living with a Red Dwarf - Center for Space and Habitability (CSH)

... the atmosphere, and heat it to the point where the atmosphere can escape to space. • i.e. it’s the rocket fuel that brings molecules up to escape velocity and can launch atmosphere out of the gravity well. • Shorter wave ultraviolet drives photochemistry, and can break up heavy molecules into lighte ...
< 1 ... 58 59 60 61 62 63 64 65 66 ... 298 >

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.
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report