... 2001 March 8 . Bright Venus . ... That's no star, that's planet Venus the second "rock" from the Sun . Blazing at -4.6 magnitude , Venus, after the Sun and Moon, is the third brightest celestial body in planet Earth's sky . ... This causes Venus to look brighter as it looms large in its crescent phases than when it is smaller and nearly full. Taken on January 28th, this dramatic picture finds a crescent Venus near its brightest to the right of a crescent Moon. ... About APOD | ...

... Classifiers We apply machine learning methods to generate classifiers from `training' data sets, each set being a particular sample of ob jects with pre-assigned class names that have measured X-ray fluxes and, wherever possible, data from other wavelength bands. ... Figure 1. ... With ClassX, one can isolate sources with a greater degree of class name ambiguity and look into why their classification in the training set differs from the OC1 classification (see Figure 2). ...

... The concerns here are similar to those for observing bright targets; saturation and blooming of the bright companion PSF must not impact the faint target. Also, one may need to consider subtracting the PSF of the bright object, and effects which limit the accuracy of that subtraction. If the bright companion will saturate and bloom, it will be necessary to rotate the CCD so that blooming along the CCD columns does not obliterate the faint target. ...

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. ...

XMM-Newton Science Analysis System . ... A different approach is done via the setting withctisrcpos =Y: all event energy corrections do not use the actual RAWY coordinate but the corresponding RAWY location of the source ( SRCPOS ) as determined by the task epframes (either automatically or via setting withsrccoords =Y). ... The task epchain may be used with the setting ccds =4 withctisrcpos =Y to process only the CCD 4 where usually the bright source is located that causes the Out-of-Time events. ...

... Albireo: A Bright and Beautiful Double . ... Such is the case of the bright double star Albireo . Seen at even slight magnification, Albireo unfolds from a bright single point into a beautiful double star of strikingly different colors. ... The brighter yellow star is itself a binary star system, but too close together to be resolved even with a telescope. ... Публикации с ключевыми словами: star system - двойные звезды . Публикации со словами: star system - двойные звезды . ...

... The two plots below illustrate two of the selection criteria: velocity width (limited by the channel width) and the HIPASS peak flux. Zoom-in on Figure 3a. The two plots below give some idea of the shape of the HI spectra. ... For Gaussian HI spectra the difference is slightly more, but for irrgeular galaxies, pairs and groups many different shapes are observed. ... Some trend towards detecting more narrow-width galaxies at higher velocities is visible. ...

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 | ...

Two major reasons: the number of stars isn't really seven (it's many more), and they all have different brightnesses, so that you see more or fewer of them depending on viewing conditions. The brightness of stars is measured on the magnitude scale, where the most prominent stars in the sky are around 1st magnitude, and the faintest you can see with your eye are about 6th. ... I think this makes it quite likely that the list will be truncated at Taygeta, giving six visible stars. ...

... 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 . ...

Nova in M31 2000 3 . ... From Giovanni Sostero (Remanzacco Observatory): at the end we have found a good Nova candidate in the course of our monitoring program in M31. ... Remanzacco Observatory Light curve This is a preliminary lightcurve of Nova M31-3 from the images we collected and those provided by others. ... vsnet-alert 5346 ] [FWD] Suspected Nova in M 31 . ... vsnet-alert 5349 ] (fwd) M31 possible nova . ... vsnet-alert 5355 ] [FWD] New image of the possible Nova in M31 (GSo) . ...

... Bad Astronomy . ... Bad Astronomy: The North Star, Polaris, is a very bright star. Good Astronomy: Polaris is a middling-bright star, easily missed. ... He said it was close to Polaris, the North Star, but he also said it was in the East. ... It's natural, I suppose, to think that such an important star should be bright, but really, that's a conceit, like thinking that the Earth is at the center of the Universe. If more people knew just why Polaris is the North Star, this Bad Idea would stop. ...

Each point in this graph represents one star in NGC 2808. The vertical axis represents the brightness (as measured through Hubble's near-infrared F814W filter) of the stars (the brightest stars near the top). The horizontal axis represents the colours of the stars, with bluer stars to the left and redder to the right (blue magnitude minus near-infrared magnitude). ...

... Now, think about a much bigger move: What do you think it would be like if the Earth moved to a different part of our Galaxy? Our Galaxy, the Milky Way, is shaped like a whirlpool: It has bands of stars that spiral around the centre, which astronomers call the Galaxy s arms . ... We live in the outer parts of the Milky Way, in one of its spiral arms. ... The small centre of the Milky Way is a much more crowded place, as this is where most of its stars are found. ...

... MOON OCCULTS PLEIADES, 23-24 FEBRUARY. ... known by different designations - don't worry if your PC programme or Atlas shows some of them with other Catalogue numbers STAR Mag Time V 624 Tau 8.2 E22.10 V 1187 Tau 8.3 E22.23 TYC 1803-188 E 8.1 E22.29 16 Tau 5.5 22.44 19 Tau 4.3 22.50 TYC 1799-306 E 8.5 E22.57 TYC 1803-104 E 8.9 E22.59 TYC 1799-184 E 7.2 E23.05 20 Tau 3.9 23.08 21 Tau 5.7 23.09 22 Tau 6.4 23.12 TYC 1804-2081 6.8 23.35 ... Clear Skies, Terry Moseley . ...

... 38 CONTENTS Karachentsev I.D., Kopylov A.I., Kopylova F. G. Distance moduli in M 101 group from brightest stars .. Tikhonov N.A., Karachentsev I.D. Maffei 2, a nearby galaxy shielded by the Milky Way.. ... Zhuravkov A.V. , Bartolini C., Guarnieri A., Piccioni A., Zampieri G. Optical behaviour of GRO J0422+32 in different brightness levels ............................................................................. telescope .. ... Cas OB5 .. ... Instrumental facilities of the 6 m telescope .. ...

... November 12, 1996 . Comet Hale-Bopp Passes M14 . ... Explanation : Comet Hale-Bopp continues its slow trek across the night sky, and can now be seen superposed near the bright globular cluster M14 . Will Comet Hale-Bopp become as bright in early 1997 as Comet Hyakutake did in early 1996? It is still too early to tell. ... Because of the size of coma , some speculate that the nucleus of Hale-Bopp is unusually large. ... Tomorrow's picture: Seven Jets from Comet Hale-Bopp . ... About APOD . ...

ATMoB "Open Cluster Observing Award " Guidelines Purpose: To promote observing among the membership of the Amateur Telescope Makers of Boston through participation in the Open Clusters Observing Awards program. Introduction: This awards program is oriented towards visually observing open clusters above magnitude 9.9. ... It turns out that a very unprejudiced and convenient method to dermine the limiting magnitude is to count the number of visible stars in certain areas on the sky. ...

... 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. ...

... The ancient chronical said about the colour rings around the Sun and the Moon, about three suns in the sky, light columns, bright lightning, different "comets" rushing to the Earth, moving among the stars or round the Earth with the sky. All these occurrences may be divided into three categories: one that occur in the near or far space, processes going on in the Earth atmosphere under the influence of cosmic factors and at last the occurrences connected with the Earth atmosphere. ... Rainbow . ...