The Cepheids of M100 . ... Credit Copyright: NASA , HST , W. Freedman ( CIW ), R. Kennicutt ( U. Arizona ), J. Mould ( ANU ) Explanation: Can this blinking star tell us how fast the universe is expanding? ... Cepheids variable stars are therefore used as distance indicators . By noting exactly how long the blinking period is and exactly how bright the star appears to be, one can tell the distance to the star and hence the star's parent galaxy. ... NASA Official: Jay Norris. ...

In autumn 1994, two groups of astronomers announced that they had discovered Cepheid variable stars in a distant cluster of galaxies. ... As the term suggests, variable stars change in brightness over time. ... Variable stars are an ideal way to get high-school students doing real science, with real data, from the real sky. ... a sky chart to find the stars . ... Students can use the nearby stars to estimate the magnitude of Delta. ... Locate the star Delta in Cepheus and estimate its brightness . ...

... January 10, 1996 . The Cepheids of M100 . ... Explanation: Can this blinking star tell us how fast the universe is expanding? ... A longer blinking cycle means an intrinsically brighter star. Cepheids variable stars are therefore used as distance indicators . By noting exactly how long the blinking period is and exactly how bright the star appears to be, one can tell the distance to the star and hence the star's parent galaxy. ... About APOD | ...

... A new bright LBV (Luminous Blue Variable) star was detected in M33 galaxy. LBV stars are the most massive stars in the final stages of evolution before exploding in of supernovae. ... The new LBV star (Fig.1) is the seventh in M33. ... It is one of the brightest LBV stars of the M33 galaxy. ... The brightest object is the core of the galaxy, - a compact star cluster comprising a supermassive black hole. The new LBV star N93351 is located down and to the left from the core. ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

... CEPHEID VARIABLE STARS: A Cepheid variable or Cepheid is a member of a particular class of very luminous, massive variable stars with pulsation periods of 1-70 days. ... The relationship is calibrated using data collected from Cepheids whose distances are determined by other means. ... Browse through the 68 CCD fits images he sent you, using ds9 and locate the Cepheid variable. ... Image credits: ESA - "http://sci.esa.int/science-e-media/img/20/cepheid-variables.jpg" . ...

... 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. ...

November 2006 Astronotes 1 Candles in the Dark Image Credit: Wikipedia.org By Colin Johnston, Science Communicator Since the mid-ninteenth century astronomers have used the principle of parallax to measure the distance to other stars. ... How then can we tell, for example, that M31, the galaxy in Andromeda, is 2.2 million light years away? It would be straight-forward to tell how far away a star was if it was exactly the same brightness as our own Sun. ...

... STScI-PRC99-19 HUBBLE FINDS VARIABLE STARS IN DISTANT SPIRAL GALAXY A NASA Hubble Space Telescope (HST) view of the magnificent spiral galaxy NGC 4603, the most distant galaxy in which a special class of pulsating stars called Cepheid variables have been found. It is associated with the Centaurus cluster, one of the most massive assemblages of galaxies in the nearby universe. ... Researchers found 36-50 Cepheids and used their observed properties to securely determine the distance to NGC 4603. ...

... Tonight's Sky . ... Search By Name Enter coordinates Use current location . ... Observing . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... How do astronomers use Cepheid variables to measure distances? ... Get instant access to subscriber content on Astronomy.com! ... If you are already registered on Astronomy.com, please log in below. ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

... V838 Mon is a member of a new class of eruptive variables which appear as a peculiar novae having late K-M type spectra in their outburst. Before its outburst, it was a wide binary system of B3V type stars. ... The B3V companion was seen in the outburst in the UV spectrum taken with HST (Rauch et al., ... In the latest spectra, the light of B3V companion was predominating in the short-wave photometric bands. ... CCD blue frames of V838 Mon before the eclipse (left) and in the eclipse (right). ...

... Bright spot spectra have been constructed by differencing the mean spectra observed at pre- and post-eclipse orbital phases. These difference spectra contain ultraviolet absorption lines and show the Balmer jump in emission. ... Model disk spectra constructed as ensembles of stellar atmospheres provide poor descriptions of the observed post-eclipse spectra, despite the fact that UX UMa's light should be dominated by the disk at this time. ... huizinga@stsci.edu . ...

Chapter 11. Specifying OpenGL Environment Variable Settings . ... Several antialiasing methods are available and you can select between them by setting the __GL_FSAA_MODE environment variable appropriately. ... To see the available values for __GL_FSAA_MODE along with their descriptions, run: nvidia-settings --query=fsaa --verbose . The __GL_FSAA_MODE environment variable uses the same integer values that are used to configure FSAA through nvidia-settings and the NV-CONTROL X extension. ...

... 2.3 Establishing the Extragalactic Distance Scale . ... 2.3.2 The Second Rung: Distances to stellar clusters . ... 2.3.4 Distances to Local Group Galaxies . ... The Luminosity Function of Planetary Nebulae . ... 3.2.2 Clusters of Galaxies . ... 4.2 Evidence for Dark Matter as a Function of Scale Size . ... 4.3 Other Dark Matter Indicators for Galaxies . ... What is the nature of the large-scale distribution of matter in the universe as traced by the three-dimensional galaxy distribution? ...

An image of the grand design of spiral galaxy M100 obtained with NASA's Hubble Space Telescope resolves individual stars within the majestic spiral arms. ... Hubble has the ability to resolve individual stars in other galaxies and measure accurately the light from very faint stars. This makes space telescope invaluable for identifying a rare class of pulsating stars, called Cepheid Variable stars embedded within M100's spiral arms. ... 617) 495-7062 . Fax: (617) 495-7356 . ...

Large Magellanic Cloud Distance from Cepheid Variables using Least Square Solutions Choong Ngeow (UIUC) & Shashi Kanbur (SUNY Oswego) ABSTRACT: We determine the LMC distance using Cepheid variables in the LMC. ... The least squares take the form: #0, if G05 m = % $µ + a + b log( P ), % = " !1, if OGLE · Recent studies have suggested the LMC Cepheid P-L relation is nonlinear (Kanbur & Ngeow 2004,2006; Sandage et al 2004). We also adopt a "broken" P-L relation with a break period at 10 days. ...

... 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. ...

The Sun is our nearest star and the source of energy for life on Earth. ... For centuries astronomers wondered whether they were clouds floating in the Sun's atmosphere, but we now know that they really are huge regions of magnetic field, about as intense as the field at the poles of an iron magnet. ... Such abrupt events were named solar flares , and what made them especially interesting was that occasionally, after a prominent flare, a magnetic storm would erupt on Earth. ...

... 4. (a) Distribution of distance from the Galactic plane, (b) kinematic diagram, and (c) relation between metallicity and distance from the Galactic plane for RR Lyrae stars with [Fe /H ] > -0.95 . ... The solid line in the middle panel is a regression line, whose slope is determined by the subsystem’s rotation rate; the open circles and dashed line correspond to stars with [Fe/H] > -0.4, and the filled circles and dashed line to stars with -0.95 < [Fe/H] < -0.4. ... next figure | privious figure . ...

... Observing . ... Home Education Workshops at Adorama Astronomy Workshop: Observing Variable Stars from the City ? February 15, 2015 . ... Beyond New York City . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . ... A History of the First Forty Years of the Amateur Astronomers Association . ... Presented by€а Adorama €аFor the Amateur Astronomers Association of New York . ... 2016 Amateur Astronomers Association of New York Designed by Press Customizr Powered by . ...