Definitions of Magnitudes and Surface Brightness 1 The magnitude system 1.1 Apparent magnitude Astronomers are stuck with the antiquated old system of magnitudes and so a clear explanation of what this system is and how it relates to more sensible units is important. ... 1.2 Absolute magnitude Absolute magnitude is a logarithmic luminosity scale. ... One usually goes by the round about process of referring to the absolute magnitude of the sun. ... Magnitudes and surface brightness 6/6 ...

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• Cepheid Variables

... For more distant stars we must use other techniques. ... Hence if we see a distant galaxy and can pick out any cepheids lying within it, we can calculate its distance. ... Here then is another method to gauge the size of the Universe and there are yet more. volume at high enough temperature a nuclear fusion reaction sweeps across the white dwarf's surface and eventually we will see a spectacularly bright new star (hence nova) in our skies. ... Why is this relevant to the size of the Universe? ...

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• http://www.armaghplanet.com/pdf/AstroTopics/Measuring%20the%20Universe/cepheid.pdf
• See a Nova in Delphinus Tonight! | Astronotes
• Leo, Virgo, Bootes and the May Night Sky Wonders | Astronotes

... Главная . ... Новости . ... Проекты . Любителям астрономии . Проект ISON . ... Подробнее . ... Категория: Новости проекта ISON . ... Метки: Космический мусор ,љ Астероиды ,љ Гамма-всплески ,љ Любителям астрономии ,љ Кометы љ . ... Метки: Космический мусор ,љ Астероиды ,љ Любителям астрономии љ . ... Новости обсерваторий проекта] - Обсерватория Кубанского государственного университета от Иванов А - 09.04.2016 11:08:49 . ... 1999-2013 Copyright "Астрономия и Телескопостроение" . ...

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Once students get the hang of it, they can find and measure the brightness of Delta Cephei in a few minutes. ... of Delta Cephei . ... Oct. ... The following table lists the measurements of Delta Cephei made by one amateur astronomer in autumn 1990. ... 4.0 . ... This activity is a simplified version of one that appeared in Hands-On Astrophysics, a series of activities prepared by the American Association of Variable Star Observers with support from the National Science Foundation. << previous page | ...

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• ASP: Accidental Astrophysics: The Devil's In the Magnitudes, Part II
• ASP: An Ancient Universe - The Age of the Expanding Universe
• ASP: An Ancient Universe - The Age of Light from the Most Distant Galaxies

Astronomers usually measure the flux of an object by collecting light with a telescope, sending it through a known filter, and then determining the power. ... But astronomers usually give their photometric results in terms of magnitudes. ... Astronomers define an absolute magnitude that is independent of the distance of a star and only depends on the intrinsic properties of the object: the absolute magnitude is the magnitude the star would have if it were 10 parsecs away from the Earth. ...

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• Determine H0 using a SQL query to LEDA
• The ABC's of Distances

... The Galactic low-mass X-ray binary GS 2023+338 was discovered during the burst on May 22, 1989 with the Japanise satellite Ginga (aka Galaxy). The flux reached 17 crabs (this unit of flux measurement is an bright X-ray source, Crab Nebula) at 10-35 keV. ... No other radio telescope worldwide carried out multi-frequency measurements. ... Upon 14 days the radio flux fell below the detection level at the RATAN-600 in relation to the decrease of the X-ray flux. ...

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In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

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• Galaxy Gallery Page II

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Astrophysics graduate student programs . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... ATCA . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

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• ATNF Media Release - December 1, 1998
• Cepheid Variable Stars Distance
• moment

... Luminosity (L) · · · · A source's luminosity is the power that it emits in radiation. ... NB Astronomers often say `flux' when they mean `flux density' · SI units are Wm-2Hz -1 -26 filter · Also used are Jy 10 Wm-2Hz -1 E= РРРF d dA dt Specific Intensity, Surface Brightness (I) · Specific intensity (or surface brightness) is the power received (or emitted) per unit area per unit frequency per unit solid angle. ч F at surface of a spherical source = I · · Specific intensity is independent of distance...

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• MERLIN Observations of the Radio Jets of SS433

STIS Instrument Handbook for Cycle 24 . ... Space Telescope Imaging Spectrograph Instrument Handbook for Cycle 24 > Chapter 13: Spectroscopic Reference Material > 13.8 MAMA Spectroscopic Bright Object Limits . ... MAMA Spectroscopic Bright Object Limits . ... For echelle observations, the global limit of 200,000 counts/s over the detector sets the magnitude limits, but you must also assure that your source does not violate the local limit, e.g., if it had a bright emission line. ... 1.61 . ...

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• John H. Debes
• ST ScI Preprint #1320
• Extragalactic Cepheid Distances by Calibrated Period - Luminosity-Color

... 2002 June 20 . Bright Galaxy M81 . ... Explanation: Big and beautiful spiral galaxy M81 , in the northern constellation Ursa Major , is one of the brightest galaxies visible in the skies of planet Earth. This superbly detailed view reveals its bright nucleus, grand spiral arms and sweeping cosmic dust lanes with a scale comparable to the Milky Way . ... The errant dust lane may be the lingering result of a close encounter between M81 and its smaller companion galaxy, M82 . ... About APOD | ...

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• APOD: 2006 July 7 - Bright Galaxy M81
• APOD: 2003 August 1 - Moons and Bright Mars
• APOD: 2003 March 17 - SN 1006: History's Brightest Supernova

THE PHOTOMETRIC RESEARCHS OF THE MERCURY'S SURFACE BY MEANS OF DIGITAL MODELS. ... The surface brightness of Mercury was measured Danjon (1933, 1949, 1953) and Harris (1961) in phase angle 3o-123o. The analysis of the various data of the integral photometric gives the results of determination of the main photometric constants for Mercury. ... THE PHOTOMETRIC RESEARCHS OF THE MERCURY'S SURFACE: S.G. Pugacheva The surface brightness of the Mercurian images was established on the geologic map Mercury. ...

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... The bright supernova (hereafter SN) in the galaxy NGC 4527 was first sighted by S. Knight (USA) on April 13.17UT at magnitude ~14.0v. The report of the sighting was subsequently forwarded by phone to the AAVSO. ... SN 1991T. The galaxy NGC 4527 is an Sb(s)II type galaxy with an apparent Blue magnitude of 11.32 (Shapley-Ames, 1981). ... An analysis of this event utilizing visual observations by amateurs, plus a light curve is presented.. ... THE LIGHT CURVE: . ... ISN SN 1991T web page . ...

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• Bright Supernova Bright Supernova
• Bright Supernova - Archives

... They worked out that first magnitude was on average 100 times brighter than the 6th magnitude star. ... This formed an equation of apparent magnitude Mv which is: Mv = -2.5 log f + constant were f is the flux of that star f = ( counts/ exposure) The images that we worked on were taken by the Polar Bear Telescope. ... One of these being that it will be combined with standard stars, which will be used to identify the area of stars and to also help identify other stars within the image. ...

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• Armagh Observatory
• Coronal Bright Points: Another Oscillating Environment
• Objects in the Sky

... Archives . ... Differential Emission Measure [Eqn] . ... Astro 301, class 1, and it took all of 20 minutes of talk about stellar magnitudes to put that notion to permanent rest. ... Now, it turns out that the human eye perceives brightness on a log scale, so magnitudes are numerically similar to log (brightness). ... frac{5}{2}\log_{10}\left(\frac{f_{object}}{f_{standard}}\right) \,,$$ . ... frac{5}{2}\log_{10}\left(\frac{L_{object}}{4 \pi d^2}\frac{1}{f_{standard}}\right) \,.$ ... Chandra Blog . ...

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• About Tom's Asteroid Flybys Service
• The AstroStat Slog Blog Archive Eddington versus Malmquist

... A star was observed at different zenith distances during one night at the Engelgardt's Astronomical Observatory in the program of atmospheric extinction study at blue. ... The determination of the star's brightness was performed with the method of photon counting. ... Variable star. ... The brightness of the variable star was measured occasionally during the other nights, and moments of maximal values of brightness (15.59m) were received on nights 2­5, the 2nd table. ... JD 2452805. ...

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• http://www.issp.ac.ru/iao/2015/booklet/b11_ia15_p_en_b.pdf

... Bad Astronomy . ... Mad Science . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... How did early astronomers determine the distance form earth to the sun, and what method is used today to determine distances in space? ... Since Huygens knew the Sun-Venus-Earth angle (from the phases), and he could directly measure the Sun-Earth-Venus angle (simply by measuring Venus' apparent distance from the Sun on the sky) all he needed was to know the distance from Earth to Venus. ...

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• Phil Plait's Bad Astronomy: Info
• Phil Plait's Bad Astronomy: Misconceptions

... For a hundred years, astronomers have been trying to pin down the exact distance to one of our nearest neighbouring galaxies, the Large Magellanic Cloud. ... In the case of the Large Magellanic Cloud, its distance was determined by looking at pairs of stars that orbit each other. ... Finding the accurate distance to the Large Magellanic Cloud is an important breakthrough, because the distance to stars in that galaxy can be used to find the distance to even more remote galaxies. ...

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• Measuring Cosmic Distances with Stellar Heart Beats | ESO
• Light echoes whisper the distance to a star | ESO
• Measuring Cosmic Distances with Stellar Heart Beats | ESO United States

Astronomy Terms - To Help You Study The Universe . Articles | ... Learning about the universe, or the study of astronomy, can be fun for the individual or for the whole family. ... Learning a few simple terms will help you with this fascinating study. ... You will use a telescope or binoculars for your observation of the sky at night. ... Celestial Terms . ... Meteor or a shooting star – the light caused when a meteoroid burns up in Earth's . ... www.astronomy.net . About Astronomy Net | ...

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• Articles written by astronomers for astronomers of all ages.
• You Can Make Stellar Images Brighter - an Astronomy Net Article
• Magnification (Power) And Using Eyepieces - an Astronomy Net Article

... galaxies . ... Hubble rules out one alternative to dark energy . ... Astronomers using NASA's Hubble Space Telescope have ruled out an alternate theory on the nature of dark energy after recalculating the expansion rate of the universe to unprecedented accuracy. ... The Hubble observations were conducted by the Supernova Ho for the Equation of State (SHOES) team that works to refine the accuracy of the Hubble constant to a precision that allows for a better characterization of dark energy's behavior...

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• First direct distance to Andromeda | Astronomy.com
• NASA's infrared observatory measures expansion of universe | Astronomy.com
• Cosmology standard candle not so standard after all | Astronomy.com