The Discovery of the Galilean Satellites . ... Probably the most significent contribution that Galileo Galilei made to science was the discovery of the four satellites around Jupiter that are now named in his honor. Galileo first observed the moons of Jupiter on January 7, 1610 through a homemade telescope. He originally thought he saw three stars near Jupiter, strung out in a line through the planet. ... Galileo's Observations of Jupiter's Moons . ... Jupiter . ...

Proposal Identification No.: P2681 Date Received: 2011­Oct­03 17:12:34 Technical Page Proposal Type: Followup General Category: Pulsars Observation Category: Galactic Total Time Requested: 60 Hours Minimum Useful Time: 2:30 hours Proposal Title: Followup of PALFA Discoveries ABSTRACT: We propose follow­up observations of 10 new pulsars discovered in the PALFA survey. ... This proposal requires coordination with GPS L3 at 1381 MHz. ...

The weather throughout this year was so extremely favorable that I have been able to observe the Sun clearly on 312 days; however, I counted only 34 groups of sunspots.. From my earlier observations, which I have reported every year in this journal, it appears that there is a certain periodicity in the appearance of sunspots and this theory seems more and more probable from the results of this year.. ... 244 . ... 149 . ... Exploration" home page (index) Glossary . Official GSFC Home Page .. ...

... The weather throughout this year was so extremely favorable that I have been able to observe the Sun clearly on 312 days; however, I counted only 34 groups of sunspots.. From my earlier observations, which I have reported every year in this journal, it appears that there is a certain periodicity in the appearance of sunspots and this theory seems more and more probable from the results of this year.. ... Year . ... Days when no . ... Observation Days . ... 273 . ... 282 . ... 244 . ... 149 . ...

M1 image More About M1 Nice Color Picture . ... M16 image More About M16 HST image . ... M31 image More About M31 Nice Color Picture . ... M42 image ; M43 image More About M42/43 Nice Color CCD Picture . M51 image More About M51 Color Image of M51 M51 Supernova . M57 image More About M57 Nice Color CCD Picture Very Deep M57 Image . ... M81 image More About M81 M81 Supernova Ultraviolet Image of M81 More about Ultraviolet Imaging . M82 image More About M82 M82 False Color M82 True Color . ...

... M31: The Andromeda Galaxy . ... Andromeda is the nearest major galaxy to our own Milky Way Galaxy. Our Galaxy is thought to look much like Andromeda. ... The diffuse light from Andromeda is caused by the hundreds of billions of stars that compose it. ROSAT Explores The X-Ray Sky . ... Caught in the act earlier this summer by the Hubble Space Telescope, the volcanic moon Io (above and right of center) and its shadow (black dot) are seen here against Jupiter's clouds. ...

home publications > mercury . ... Astronomy Beat . ... Nearly four centuries ago, Galileo's simple observations of Earth's planetary sibling, Venus, buoyed the proponents of a Copernican universe. ... The Italian astronomer had settled into a new house in Florence and had begun to observe Venus, which in November 1610 would have appeared as an evening star, bright in the western sky after dusk. ... From these two observations, Galileo inferred that Venus must orbit closer to the Sun than does Earth. ...

Follow-up astrometry and recoveries are made with the ANU 40 inch (1.0-m) f/8 reflector at Siding Spring Observatory (IAU code 413). ... A routine follow-up of 2003 WY153 on 2003 Dec 15 became much more than routine when a faint object with unusual motion vector was found close to the target asteroid. ... During routine astrometry with the 1.0-m to improve the orbit of the Apollo asteroid 2004 CB, the asteroid was found on March 30 to have a short tail! ... Siding Spring Survey Main Page . ...

... 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. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Planets . ... Earth Satellites . ... A Scorched World: too distant to image, Kepler-10b is depicted here by a NASA artist (Image credit: NASA/Kepler Mission/Dana Berry) . The Kepler satellite looks for planets passing between their parent star and Earth. ... Placed beside our homeworld, Kepler-10b would be about 40% wider than Earth. ... Possibly only occasional jagged islands of metal and rock break the monotony of its glowing lava oceans. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Although the comet itself never comes dangerously close to the Earth, the particles of dust that it has shed during its many past passages through perihelion found their way into the Earth's atmosphere, appearing as meteors in the cold December sky. ... Animation 1 . ... An Ursid meteor captured by the Armagh Observatory's NE-facing meteor camera in the early morning of 23rd December. ... Meteor Showers Online . ...

EMBARGOED UNTIL: 9:20 AM CST, January 6, 1999 CONTACT: John Biretta Space Telecsope Science Institute, Baltimore, MD (Phone: (410) 338-4917; Internet: biretta@stsci.edu) HUBBLE DETECTS FASTER-THAN-LIGHT MOTION IN GALAXY M87 Astronomers reported today discovering clouds which appear to move many times faster than the speed of light, shooting out from the region of a black hole at the center of the M87 galaxy. ... It's an illusion created by the finite speed of light and rapid motion," Biretta said. ...

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? ...

... In the light curve depicting their observations, definite trends are noted, here is a "thumb-nail" analysis of the the magnitude estimations of the bright SN (1989B) in the galaxy NGC 3627 (M66). ... 10 (IAUC # 4742) 2/25 13.3 16 j 2/27 13.5(*) 18 lc 2/28 13.8 19 p 3/1 13.2 20 w 3/2 13.5 21 a 3/4 13.8 23 p 3/6 13.3 25 c 3/7 13.3 26 c 3/8 14.1 27 m 3/8 13.3 27 r 3/9 13.4 28 c 3/9 14.1 28 m 3/10 13.6 29 j 3/10 14.0 29 a 3/11 13.6 30 c 3/11 13.5 30 r 3/11 13.7 30 s 3/13 [13.69 CCD Mag.] ...

... July 6, 1996 . Edmond Halley's Greatest Discoveries . Explanation: Sir Edmond Halley was quite a discoverer. Born in 1656, he computed in 1705 that a bright comet was periodic and would make another appearance in 1758. The comet appeared as predicted and is now known as Comet Halley . ... Perhaps Halley's greatest discovery, however, was that his contemporary Isaac Newton had discovered a powerful mathematical formulation of gravity. ... About APOD | ...

... EXPN DNO D A T E UT TIME FQ SOURCE CORR-Telescopes VT734 355-MO Dec 21 08:00-21:00 C TAU-A Pointing VT735 356-TU Dec 22 08:00-21:00 C TAU-A Pointing VT736 358-TH Dec 24 09:00-20:00 K ORIONKL Pointing VT737 359-FR Dec 25 09:00-20:00 K ORIONKL Pointing VT738 360-SA Dec 26 09:00-20:00 C 0528+134 Mitk-UD KA SH W018c 364-WE Dec 30 06:00-15:00 L 0552+398 Socr-VLBA W071n 6-WE Jan 06 10:00-17:00 L J0745+10 Mitk-AT HO MP UD SH KA W059e 7-TH ...

Next: The Evolutionary Status of Up: No Title Previous: Massive X-ray Binaries . After 25 years of pulsar studies, a radiopulsar has been discovered in a binary system with a massive optical companion (Johnston et al. ... As shown in the very first calculations of joint evolution of NS and normal stars in binaries (Kornilov and Lipunov, 1983b[ 86 ]) a considerable fraction (maybe, the majority) of NS in binary systems having an optical companion must be at the ejector љ (E) state. ... Systems . ...

... Tonight's Sky . ... Sky this Month . ... Star Atlas . ... stars . ... The Sky This Week: April 1 - 10 . ... Observing springtime deep-sky objects with a large telescope . ... Why do some stars appear to flash a variety of different colors when you look at them through a telescope? ... So, Earthт??s atmosphere will bend some colors from especially bright stars more so than others, which makes the source look like itт??s flashing colors. Get instant access to subscriber content on Astronomy.com! ...

... October 10, 1604 a new star unknown before appeared in Snakebearer constellation. ... Mostly Kepler saw farther than Galilei , understanding that planets were influenced by the Sun. ... The most of all wonders is that I opened four new planets and observed their own movement and the movement according each other and according the other stars. These new planets are mooving around the other great star as well as Venus, Mercury, and perhaps the other known planets are moving around the Sun". ...

... 227Wink This paper containes an investigation of 91 sources which appear to be point sources when observed with the angular resolution of the 100-m telescope at 4.9 GHz, teta_a = 2.6', and which we expected to be HII regions. The basic search list was prepared from the 4.9 GHz survey of the galactic plane by Altenhoff et al. ... In the present paper we list 4.9 GHz flux densities only for sources for sources for which we present new observations. ... source structure indicated . ...