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. ...

The Astronomical Catalog portion of CDBS contains several atlases consisting of both observed and model stellar,galactic, and emission line object spectra as well as HST standard stars spectra are available in STSDAS table format for use in the calibration of HST instruments, with synphot, with the exposure time simulators, or for any other purpose. this is it There are two independent directories containing the spectra of ultraviolet and optical standard stars. ... For details see K93MODELS . ...

Astronotes Armagh Planetarium's Stellar Blog! ... Space Flight . ... Earth Satellites . ... Leonid meteors seen from 13 km altitude aboard an aircraft during the 1999 Leonids Multi-Instrument Aircraft Campaign (Leonid-MAC). Comet Tempel-Tuttle provides the cometary debris for the Leonid meteor shower. ... Every 17-19 November Earth crosses Tempel-TuttleтАЩs orbit and the Leonids become visible. With clear, dark skies observers may see 10 to 15 Leonid meteors every hour on those mornings. ...

... The sample of the Local Volume galaxies (distance smaller than 10 Mpc) gives a unique opportunity to study the properties of galaxies including the weakest objects: the absolute magnitude M B -10 and the virial mass M vir 10 9 M x263C;. ... Luminosity function of the Local Volume galaxies. ... The luminosity functions for galaxies are presented: red dashed line - from the 2dFGRS survey (Norberg et al. 2002); blue dash-dotted line - from the SDSS survey (Blanton et al. ...

... Massive Stars in Open Cluster Pismis 24 . ... Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it a record holder. This star is the brightest object located just above the gas front in the above image. NGC 602 and Beyond . ... Near the outskirts of the Small Magellanic Cloud, a satellite galaxy some 200 thousand light-years distant, lies 5 million year young star cluster NGC 602. ...

The ESA/ESO Astronomy Exercise Series 2 . The Distance to Messier 100 as Determined by Cepheid Variable Stars . ... The small variations in distance to the individual Cepheid variable stars in the Cloud are negligible compared with the much larger distance to the SMC. ... In this way Cepheid variable stars can be used as one of the 'standard candles' in the Universe that act either as distance indicators themselves or can be used to calibrate (or set the zero point for) other distance indicators. ...

... Submitted by Al Takeda on 02/13/2014 12:57:50 . Supernova SN2014J in M82 . A Type 1a supernovae has exploded in the irregular galaxy M82. ... Acquisition by Images Plus 4.0a, Calibration, normalization, alignment, combine and digital development processing by Images Plus 3.82b, Additional processing using Adobe Photoshop. ... ATMoB Clubhouse, Westford, MA, 7 February 2014 . ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... 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 . ...

Rastorguev А.S. "Astronomical Distances" (Lecture course for postgraduates, 2009-2016) . Part 1. ... Trigonometric parallaxes of stars. Moving clusters distances. ... Photometric distances: general approach. Normal stars as "standard candles". ... Main Sequence fitting or distance scale of star clusters. ... Moving photospheres technique. Cepheid distance scale and P-L relations. RR Lyrae distance scale. ... Globular clusters luminosity function. ...

... A theory suggests that a certain sub-class of gamma-ray bursts all have the same absolute magnitude. ... The author claims that this absolute magnitude is so different from that in the previous sample that this must belong to a new sub-class of gamma-ray bursts. ... To do this, there needs to be some feature in their spectra which correlates with their absolute magnitude. ... Consider a telescope which is continually monitoring a star, looking for transits due to planets orbiting this star. ...

... 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 | ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... Australia Telescope Online Archive (ATOA) . ... Australia Telescope 20GHz Survey . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... Tips on holding a viewing night . ... Gas and Galaxy Formation . ...

... Tonight's Sky . ... Star Atlas . ... stars . cosmology . ... Sky Events . ... Cosmology standard candle not so standard after all . ... Astronomers have turned up the first direct proof that "standard candles" used to illuminate the size of the universe, termed Cepheids, shrink in mass, making them not quite as standard as once thought. ... When using Cepheids as standard candles, we must be extra careful because, much like actual candles, they are consumed as they burn." ... Atlas of the Stars . ...

... Cross-shaped galaxy ZGC 2315+03 (Fig.1) has been described by Zwicky (1971) as ``post-eruptive or the result of the crossing of a compact galaxy through an edge-on spiral'' . This object was included in the Polar-Ring Catalog (C-71) by Whitmore et al. (1990) as a possible candidate for Polar-Ring Galaxies (PRG). ... One of them is galaxy 'disk' and the other is 'polar-ring'. ... The facts against the polar-ring nature of ZGC 2315+03 can be summarized as follows: . ...

logd25 is the decimal logarithm of the length the projected major axis of a galaxy at the isophotal level 25 mag/arcsec 2 in the B-band (this is the diameter of the galaxy if it is a disk). Many papers were devoted to the study of diameters and specially to the reduction to the standard system defined by the isophote at the brightness of 25 B mag/arcsec 2 . ... The shape of the galaxy at the same isophotal level (B=25 mag/arcsec 2 ) is defined in the parameter logr25 . ... HyperLeda . ...

The project of the informational system creation on the problem of evolution of radio galaxies, as a part of the "Big Trio" project aimed on studing of distant radio galaxies, is designed. This system allows a user to operate with simulated curves of spectral energy distributions (SED) to estimate ages and redshifts by photometry data. Authors use SEDs of several models for different types of galaxies. ... The HTTP and e-mail access is organized to this system. ...

... Dark matter in normal galaxies . ... I will pay attention to such issues as the constraints on dark matter profile, micro-lensing counts from the galactic bar, rotation and the structure of the bar. One of the central issues of the modeling is the exchange of the angular momentum between the disk and the dark matter. ... Our results indicate that in realistic models the exchange of angular momentum between the bar and the dark matter is much smaller than previously estimated. ...

The LCDM paradigm: successes and challenges on scales of galaxies Anatoly Klypin (NMSU) LCDM · · · · DM profiles, concentrations, .. Clustering of galaxies: P(k) and correlation functions Satellites: abundance, number-density profiles Galaxies and Dark Matter: abundances Dwarfs. ... Springel et al 2008. ... Klypin et al 2010. ... Observations - LCDM: just enough Magellanic Clouds Observations LCDM Vmax > 50 km/s Busha et al 2010 Dark matter profiles: standard LCDM Aquarius simulation. ...

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

... VLA observations and Tully-Fisher distances of gas-poor spiral galaxies in the Virgo Cluster Region . ... The HI-H2 Pressure Relation In Early-Type Galaxies . ... Tracing evolution of early-type spirals through the neutral hydrogen window . ... An Arecibo HI 21-cm Absorption Survey of Rich Abell Clusters . ... The Arecibo Ultra-Deep Survey . ... Absorption in varying galactic environments seen in HI surveys . ... Early-type galaxies with neutral hydrogen in the Virgo cluster from the ALFALFA survey ...