... Longitude . ... All points on the same line of longitude experienced noon (and any other hour) at the same time and were therefore said to be on the same "meridian line", which became "meridian" for short . ... As the Earth rotates around its axis, at any moment one line of longitude--" the noon meridian "--faces the Sun, and at that moment, it will be noon everywhere on it. ... On Earth , the equator is divided into 360 degrees, with the zero meridian passing Greenwich and with the longitude angle ...

On 6 may 2001 the azimuth was parked at az=214.4 degrees and the dome was at 19 degrees za with motors off and the brakes on. At 7:40:49 the azimuth started moving do to the wind. ... The operators began moving the dome downhill at azimuth 258 degrees. The dome was at 18 degrees by the time the azimuth stopped moving. The azimuth rail had been greased the previous week. ... The red shows the dome position during this time (the top red line is 19 degrees and the bottom one is 18 degrees). ...

Classroom Activity: Pinhole Protractor Gene Byrd and Renato Dupke . ... We cannot directly perceive the distances or sizes of far-away objects. Instead, our eyes only detect the angular size of objects. ... In Part II, which will appear in a future issue of The Universe in the Classroom, students will see how astronomers use parallax -- an extension of binocular vision -- to determine the distances of stars in the Sun's neighborhood. ... distance = 57.3 x physical size angular size (in degrees). ...

... In polar coordinates, the point P is defined by its distance r from the origin O (see drawing) and by its polar angle ("azimuth" on a map) between the x-axis and the "radius" r = OA, measured counter-clockwise. ... When one or both are negative , the angle f is larger than 90 degrees, and such angles never appears in any right-angled triangle. ... There is a simple solution , though: use the above equations to re-define sin f and cos f for such larger angles! ... But it also works for larger angles....

... More on 51 Peg: . The discovery of a Jupiter--mass planet in orbit around the solar--type star 51Peg has been reported by Michel Mayor and Didier Queloz (Geneva Observatory) on October 6th at the 9th Cambridge workshop on "cool stars, stellar systems, and the sun" held at Florence (Italy). ... Recall that the measurements of radial velocity only yield v sin i which in turn gives us M sin i. For most values of i, sin i will be greater than 0.5 and this gives a mass estimate of 0.5 Jupiter masses. ...

... The Gum Nebula Supernova Remnant . ... Spiral Galaxy In Centaurus . ... Centaurus, the Centaur, is one of the most striking constellations in the southern sky. The lovely Milky Way flows through this large constellation whose celestial wonders also include the closest star to the sun, Alpha Centauri, the largest globular star cluster in our galaxy, Omega Centauri, and the closest active galaxy, Centaurus A. Double Eruptive Prominences . ... A Crescent Nebula Star Field . ...

... Q: How do I best determine an observation's actual orientation? ... The science header keyword ORIENTAT is populated by adding the angle between the HST V3 axis and the detector Y axis to what we will call the "commanded roll" (North to V3 through East). ... The commanded roll can be determined by subtracting the beta_2 from ORIENTAT. ... Relying on the jitter file's measured roll if a problem is found either with the science header population or with the execution of the commanded roll. ...

Program: TRACE Purpose: TRACE plots image values at user given positions as function of distance to a plot centre (in 2-d (sub)sets). Category: ANALYSIS, PLOTTING File: trace.c Author: M.G.R. Vogelaar Keywords: INSET= Give set (, subset): Only one subset is allowed. ... XYBOX= Give size of box around one pixel: [3,3] The resulting value at a selected position is an average of the pixels in the defined box around that position. ... POSITION= Give position x, y: Physical values are allowed. ...

I was wondering what conditions should be met to have the "darkest" sky .. ... Upon the above publication of the Southern Galactic hemisphere, TunГ Tezel started seeking opportunities to create the Northern counterpart image. ... So, the initial quest of having the darkest possible sky have delivered us these two all-sky images of the two galactic hemispheres as seen from Planet Earth. Zoomable and 'full-screenable' fisheye view of the "darkest sky" Southern Galactic Hemisphere image. ...

... After all we cannot send a probe to the star Altair to confirm that it is 17 light years away. ... The "Bessel determined that the star 61 Cygni was about ten light years away" Earth goes around the Sun in one year, so in six month it is in the opposite position in its orbit. ... In 1838 Bessel determined that the star 61 Cygni had a parallax of 0.314 arcseconds and therefore the star was about ten light years away (today the distance is more precisely measured to be 11.4 light years). ...

... Bad Astronomy . Misconceptions . ... Bad Astronomy : The Moon only shows one face to us because it is not rotating. Better astronomy : The Moon only shows one face because it is rotating, once every time it revolves around the Earth. ... Place the Moon model on the table about 30 centimeters (one foot) away with the X facing the Earth model. ... You'll see that to keep the X facing the Earth model, you have to rotate the Moon model as it goes around the Earth model . ... 2008 Phil Plait. ...

. Ryoanji Temple (with its famous rock garden) and around: page 24 . d29. A bug which produces loud high-pitched noise. The actual length is about 5-6 cm. previous page | title page | jump to large size | index | next page

Next: A box, to include Up: To produce a region Previous: To produce a region . select cursor and circle . When in the image window, the mouse now has a box shape with an arrow at the upper left corner. The mouse buttons act as follows: . LEFT - to move the center of the circle at the position of the arrow point. ... RIGHT - idle. center the circle at the point source by positioning the arrow point and clicking on the LEFT mouse button. A circle will appear at the arrow position. ...

It is possible to piece together the processes that have shaped the observed characteristics of a galaxy by studying its stars in detail. The Large Magellanic Cloud (LMC) is an excellent candidate for this type of study because of its favourable viewing angle and ongoing star formation. I present the results of high-resolution VLT/FLAMES observations of ~80 red giant stars around star cluster NGC 1846, located in the disc of the LMC. ...

Next: Time coordinate system (TIMCOORD) Up: Coordinate Definitions used by Previous: Coordinate Definitions used by Contents . The CAL makes use of the following spatial coordinate systems . PIXCOORD0: Telemetry-related CCD pixel coordinate system . ... PIXCOORD1: Node-oriented CCD pixel coordinate system . ... The pixel coordinate system is, thus, node-oriented . ... CAMCOORD1/CAMCOORD2: Camera reference systems . ... Camera unit(s) . alignment of CAMCOORD1/2 axes in PIXCOORD1 frame . ...

... 2008 August 1 . Moon Games . ... But apparent angular size , or the angle covered by an object, can also be important to Moon enthusiasts . ... Of course the Sun is much larger than the Moon, 400 times larger in fact, but today the New Moon will just cover the Sun. ... Solar eclipses illustrate the happy coincidence that while the Sun is 400 times the diameter of the Moon, it is also 400 times farther away giving the Sun and Moon exactly the same angular size . ... About APOD | ...

... DIGITAL EDITIONS . ... Tonight's Sky . ... The Magazine . ... Observing . ... Magazine . ... 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 . ... All around Auriga . ... 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 . ...

. There are a range of easy to use commands that provide a great degree of flexibility in how you move around the contents of the file you are editing. Many of these commands can be combined with a numerical value to extend their functionality. Move the cursor along a line . Move the cursor between lines . Move between text blocks . Move over the file .

... An OBJECT column gives the name of the object observed (usually a star name). ... In critical cases, it is common practice to measure sky on two or more positions around a target object, and these positions must be identified. ... A general treatment of this problem requires a column called OBJECT, bearing the usual name of the object (as in the star tables); a column labelled STARSKY, to distinguish between star+sky, star alone, or sky alone; and additional columns to identify the sky position. ...

Aristarch is Copernic of Classic World. ... First Aristarch determined the fact for how many times the Sun was father then the Moon and then he compared the Sun and the Moon with the Earth. ... Only the Moon rotates around the Earth. ... Gipparch suggested that the Sun turned around the Earth steady and in circumference but the Earth is displaced according its centre. ... The orbit point in which the Sun is nearer to the Earth Gipparch called perigee and the most remote one he called apogee . ...