... One striking feature is a small source of almost pure H 2 line emission, which is located near one of the compact sources in Orion reported by O'Dell and collaborators (HST-18 = 203-504). ... H-H objects, Proplyds, Orion Bar, H 2 . ... We obtained a series of images across the bright rim of the Orion Bar near the peaks of mm-wave molecular line emission with NICMOS cameras 1-3 (NIC1, NIC2, NIC3) in several filters on 1998 February 18. ... The suggestion of an H-H object does not seem compelling. ...

Databases (NSDC) of the Natural Planetary Satellites. ... NSDC: Database of astrometric observations of Natural Planetary Satellites . ... They are thoroughly looking for observations in different sources, creating their owndatabases which are then mostly inaccessible to other researchers. ... In the file "content" with explications, the reference is given to the data source as well as the bibliographic reference. ... Data sources. ... Why a specific bibliographic database for Natural satellites? ...

A forthcoming mutual events of planets and astrometric radio sources . ... Radio astronomy observations of close approaches of the Solar System planets to compact radio sources as well as radio source occultations by planets may be of large interest for planetary sciences, dynamical astronomy, and testing gravity theories. ... close approach, radio source, VLBI observation, mutual events. ...

Next: Population Synthesis of X-ray Up: Cosmic Rays and Evolution Previous: Supernova Explosions . Immediately after the discovery of pulsars, especially of the Crab pulsar,   it became clear that rapidly rotating NS are copious sources of relativistic particles. ... Figure 37: Evolution of magnetorotational energy of NS in elliptical and spiral galaxies. ...

... Articles | ... Forums . ... 230 deg . 49 deg . ... 130 deg . ... More Info . ... 210 deg . ... 168 deg . ... 249 deg . ... 195 deg . ... 271 deg . ... 110 deg . ... 338 deg . ... July 15 . 247 deg . ... 224 deg . ... 340 deg . ... July Phoenicids (PHE) . ... August 10 . 341 deg . ... 339 deg . ... 307 deg . ... 334 deg . ... 335 deg . ... 286 deg . ... 327 deg . ... 262 deg . ... 102 deg . ... 153 deg . ... 117 deg . ... December 2 . ... 123 deg . ... 100 deg . ... www.astronomy.net . ...

Stellarium 0.12.3 . ... FileљStructure . FileљList . ... core . modules . Meteor.hpp . ... 46 љ Meteor ( const StelCore *, double v); . ... 64 љ Vec3f position; . 65 љ Vec4f color; . ... 67 љ : position( Vec3f (pos[0], pos[1], pos[2])), color(color) {} . 68 љ VERTEX_ATTRIBUTES( Vec3f Position , Vec4f Color); . ... 75 љ Vec3d obs; // observer position in meteor coord. system . ... 88 љ double xydistance; // distance in XY plane (orthogonal to meteor path) from observer to meteor . ...

For around forty years, astrophysicists have observed the annihilation of positrons in the Galaxy at a prodigious rate. ... The fact the Galactic bulge far outshines the disk in annihilating positrons which are injected into the ISM at low energies makes the source of the positrons difficult to identify, as the main source of such positrons are prima facie located in the Galactic disk. ...

... 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. ...

... the time of observation . ... Observing the Changing Position of the Sun To Establish Cardinal Directions . ... Observations of the Sun's apparent movement across the sky and its pattern of rising and setting in the east and west horizon helped to establish the cardinal directions. ... The final stage of the Sun's return was marked by the observation that the Sun had reached its highest altitude when the full width of your mitted hand could fill the gap between the Sun and the horizon. ...

Lectures . ... Home Lectures Lecture Series 2010-2011 Lecture Series 2010-2011 ? Greening the Earth Using Space Resources? by Greg Matloff . ... Lecture Series 2010-2011 . ... 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 . ... Amateur Astronomers Medal . ... 2016 Amateur Astronomers Association of New York Designed by Press Customizr Powered by . ...

... Energy . ... Solar Wind . ... Field . ... 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. For some reason the field slows down the flow of heat from the Sun's interior and keeps sunspots slightly cooler than their surroundings. ... Solar Eclipses . ...

... The 2MASS Galaxy Sky . ... Venus, the second closest planet to the Sun, is by far the brightest of the three planets gathered in this weekend's western sky at sunset. ... From Earth, we usually see Saturn's rings from the same side of the ring plane that the Sun illuminates them. ... As the Earth rotates to eclipse the Sun, sunset rises up from the ground. ... From top left to bottom right are the lovely but distant galaxies M61, NGC 4449, NGC 4725, NGC 5068, NGC 5247, and NGC 5775/5774. ...

... Spherical aberration, coma, and astigmatism are also easily observed using the star test. ... Off-axis images are complex. ... Fig. ... Diffraction by a circular aperture as a function of defocus for no aberration Airy Disk 1 wave defocus Less than 1 wave defocus Fig. ... Diffraction by a circular aperture as a function of defocus for third-order spherical aberration Paraxial Focus Small distance inside paraxial focus Moderate distance from marginal focus Immediate neighborhood of marginal focus Fig...

... Exams and Homework . ... Local Astronomy Stuff . ... Jeff Willick's Cosmology from Stanford . Some good Internet tutorials on Cosmology . A good primer on different Galaxy types . Some Essays by Joe Silk - good information . ... First Homework Assignment (Due June 30) . Second Homework Assignment (Due July 21) . Third Homework Assignment (Due August 4) . Final Exam now Available until August 11 . This Search Engine is Best for Homework . ...

... Tonight's Sky . ... The Magazine . ... Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Astronomy for Kids . ... January 2006 resources . FROM THE January 2006 ISSUE . ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ... Astronomy Magazine . ...

... Exposure Time Calculator (ETC) . Survey processing . ... VISTA is a 4-m class wide field survey telescope for the southern hemisphere, equipped with a near infrared camera (1.65 degree diameter field of view at VISTA's nominal pixel size) containing 67 million pixels of mean size 0.34 arcsec and available broad band filters at Z,Y,J,H,K s and a narrow band filter at 1.18 micron. A wide field visible camera, if constructed, could also be used on VISTA. ... Tile . ... ESO VISTA Public Surveys . ...

Pulkovo Database of Observations of Visual Double Stars . ... Catalog of relative positions of visual double stars, based on photographic observations performed since 1960 in Pulkovo on the 26-inch refractor (A.A.Kiselev, O.A.Kalinichenko, O.V.Kiyaeva, N.A.Shakht, L.G.Romanenko, I.S.Izmailov, O.P.Bykov, K.L.Maslennikov, E.A.Grosheva, D.L.Gorshanov), 2010 . ... Enter either ADS or WDS number. Click here to display full list of visual double stars observed at Pulkovo. ADS . ...

NMW survey overview . Access image archive . ... The New Milky Way survey aims to detect bright (V<13.5) optical transients near the Galactic plane using an automated wide-field (8x6 deg.) system capable of surveying the whole Milky Way area visible from the observing site in one night. ... All images obtained during the transient search survey are available online (please use the image archive access form ). ... Images per field: . ... Images per night: . ... Milky Way imaging time: . ...

This is possible if you do it in the following way, that is if you use the new continuation sign "&" at the end of the old line, but in position 73 so that it doesn't conflict with Fortran 77, and also choose the "&" sign as the almost arbitrary character in column 6, in order to get continuation according to Fortran 77. ... Comments are an incompatibility problem between Fortran 77 and Fortran 90, but of course not between fixed and free forms of Fortran 90 since the "!" is permitted in both. ...

Statistics of sunspot activity . The sunspot indices . ... NGDC's observations . The solar regions . ... Average annual indices . ... December . ... December, 2013 . Visual indices of solar activity by National Geophysical Data Center . ... Average . ...