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Quick facts #2: The two
Quick facts #2: The two

c - Fsusd
c - Fsusd

What is your real star sign - teacher notes
What is your real star sign - teacher notes

Earth_Universe04
Earth_Universe04

... The Orion Nebula is a wellknown emission nebula ...
temperature - University of Texas Astronomy Home Page
temperature - University of Texas Astronomy Home Page

DSLR photometry - British Astronomical Association
DSLR photometry - British Astronomical Association

... have been used. They are extremely sensitive and can be used in a photon counting mode to count individual photons, but only measures one star at a time. Photomultiplier tubes are still used for photometry today. ...
Galaxies, Cosmology and the Accelera`ng Universe
Galaxies, Cosmology and the Accelera`ng Universe

The Universe
The Universe

... A star is stable when its size remains constant over time. All stars have a stable period in their lives, the length of which is determined by their mass. The Sun is halfway though its nine billion year stable phase. ...
printer-friendly sample test questions
printer-friendly sample test questions

... Based on apparent magnitude, the Sun is the brightest star (-26.40) and Deneb is the dimmest star (1.25). Absolute magnitude shows Rigel to be the brightest star (-8.61) and the Sun to be the dimmest star (4.80). Brightness of stars is traditionally expressed as magnitude. The more negative the valu ...
OUSNMAR05 - The Open University
OUSNMAR05 - The Open University

... Observing the Moon. Spring provides an excellent opportunity for evening observation of the Moon. From the thin waxing crescent (particularly favourable) to near Full the Moon has a northerly declination. Observe along or near to the terminator where long shadows show greater detail of the Moon’s to ...
Lecture 1
Lecture 1

... the screen from the four corner chairs in this room. Describe what happens to my measurement of the angular separation. • I sit in the middle of the room and measure the angular separation of two dots on the screen. Someone rotates the walls of the building by 90 degrees. What happens to my measurem ...
observingnebulaeclusters-1
observingnebulaeclusters-1

... above the critical limit required for stars to form within the nebula. Visible to the naked eye as the middle "star" in the "sword" of the constellation Orion, the nebula is located 1500 light years from Earth. A closer image taken with the Wide Field Planetary Camera 2 aboard the Hubble Space Teles ...
The Brightness of Stars
The Brightness of Stars

... Quantifying the brightness of stars started with Hipparchus (2nd C. BC) and his magnitude scale  He designated the brightest star he could see as a “1” magnitude and the dimmest a “6” magnitude  Astronomers still labor under a more quantified version of this system  One tragic consequence is that ...
HR Diagram
HR Diagram

... It has been shown through observational data of many stars that the more massive a star, the more luminous it is. If you observe the H-R diagram on the cover of the lab, it is clear that there are fewer luminous stars as compared to the less luminous ones. In terms of the diagram, there are more sta ...
Astro history 1
Astro history 1

... sentence: no parallax of stars, no winds, not flung off earth..didn’t have modern concept of inertia, gravity, and distance to stars. 9. List another reason why Aristotle favored a geocentric model—explain his reasoning in one ...
Search for Life in the Universe
Search for Life in the Universe

... – Extrasolar planets around main sequence stars discovered in 1995 – Planets around neutron stars discovered previously – Spectroscopy (>100 cases): detect Doppler shift of stellar motion around center of mass – Astrometry (1 case): detect angular motion ...
Surveys of Stars, The interstellar medium
Surveys of Stars, The interstellar medium

... We can “weigh” stars that are in binary systems (two stars orbiting each other). Fortunately, most stars fall into this category. ...
types of stars, luminosity, and brightness
types of stars, luminosity, and brightness

... star. 5. The absolute brightness is the brightness that would be measured at a standard distance of 10 pc. Apparent brightness is the brightness of a star measured from Earth. 6. Absolute brightness is the luminosity of a star as it would be measured at 10 pc. Luminosity is the intrinsic energy per ...
WINNING STORY - Atlantis Short Story Contest
WINNING STORY - Atlantis Short Story Contest

... I was slowly floating, completely at ease, when I realized I had just gone past the two most conspicuous of the stars that make up the Orion constellation. I was taken aback by how large, mighty and bright they were. From people’s viewpoint on Earth, it looks like these celestial bodies are located ...
Second
Second

... Stellar death: stellar remnants. ...
Observations of gravitational microlensing events with OSIRIS
Observations of gravitational microlensing events with OSIRIS

... apparent brightness of 16.6 (Küppers et al. 2007); this is better than most microlensing observations from the ground. We may therefore assume that the error margins of the photometric measurements carried out with OSIRIS allow theoretical modelling of the event with the required accuracy. The numbe ...
Evolved Stellar Populations
Evolved Stellar Populations

...  In the centre the metallicity is low (Z<0.001) compared to a ring around it (Z>0.002).  The stellar population is on average 7-8 Gyr old.  Map resolution of 3-13 arcmin2.  No correction for rotation yet. ...
Variable star information
Variable star information

... Another class of variable stars owe their change in brightness to their irregular shape and/or to their non-uniform surface. In some cases, the star's shape may not be a perfect sphere, but rather an ellipsoid. Alternatively, the brightness across the surface of the star itself may vary because of t ...
Some Facts and Hypotheses regard
Some Facts and Hypotheses regard

... been mistaken for a star, There is no known instance of a new star appearing and remaining permanently bright. However, it is certain that there are genuine cases of missing stars, which cannot be explained away by any supposition of mistaken entries, It may be that such stars are in reality periodi ...
Star Classification - University of Louisville
Star Classification - University of Louisville

... A star called Betelguese is extremely old, but also extremely big. In fact, it is 500 times wider than the Sun and would, if it was at the center of the Sun's Solar System, be big enough to stretch nearly to Jupiter. This giant star will collapse in a huge explosion called a supernova and will becom ...
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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.
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