
	Where results make sense

Topic: Astrometry

Related Topics

Proper motion

Stellar astronomy

Observational astronomy

Cepheid variable

Positional astronomy

Hipparcos

Star catalogue

Pulsar planets

Astronomy

Luminosity

Henry Draper Catalogue

Parallax

Parsec

Optical astronomy

Astrophysics

In the News (Mon 28 May 12)

EXECUTIVE POWER

Iran

ANALYSIS

Pakistan

Family compact

	Astrometry and Celestial Mechanics
		Astrometry was born to accurately mapping the positions of the "fixed" stars and recording the motions of the planets.
		Astrometry and celestial mechanics are so related that they may be considered a single branch: for this reason, the Scientia websites are only two, astrometry.org and astrophysical.org.
		Astrometry and celestial mechanics have been important in history for sailing (maritime navigation), since navigators used to calculate their position on Earth upon the observation of stars.
	www.astrometry.org (189 words)

	Astrometry - Wikipedia, the free encyclopedia
		Astrometry is a branch of astronomy that deals with the positions of stars and other celestial bodies, their distances and movements.
		Astrometry dates back at least to Hipparchus, who compiled the first catalogue of stars visible to him and in doing so invented the brightness scale basically still in use today.
		Astrometry is also involved in creating the cosmic distance ladder because it is used to establish parallax distance estimates for stars in the Milky Way.
	en.wikipedia.org /wiki/Astrometry (593 words)

	TPS: Extrasolar Planets (Site not responding. Last check: 2007-10-21)
		Astrometry is the science (and art!) of precision measurement of stars' locations in the sky.
		This is made plain by the fact that although astrometry is the oldest method of searching for extrasolar planets, and despite numerous claims of discovery that have been made over the past 60 years, no extrasolar planets have as yet been found by this method.
		Astrometry, by its very nature, is highly sensitive to the distance of a celestial object from the Earth.
	www.planetary.org /extrasolar/astrometry.html (1206 words)

	ESA Science & Technology: Astrometry with Gaia
		The first space-based astrometry mission, ESA's Hipparcos satellite, demonstrated that milliarcsecond accuracy was achievable by means of a continuously scanning satellite which observed two directions simultaneously.
		In addition, the global nature of the measurements, the fact that the positions and changes in positions caused by proper motion and parallax are determined in a reference system consistently defined over the whole sky, leads to the determination of absolute parallax measurements.
		Global astrometry has many intrinsic advantages over pointed observations: a global instrument calibration can be performed in parallel with the observations; and the interconnection of observations over the celestial sphere provides the rigidity and reference system needed for the kinematical interpretation of the observations themselves.
	sci.esa.int /science-e/www/object/index.cfm?fobjectid=31365 (295 words)

	Thoughts on astrometry
		3) Astrometry as one of many measured parameters: For the vast majority of objects, astrometry will be used to complement photometry, position, etc., to aid in our understanding of an object, and particularly with this object as a member of a group or class.
		I still view astrometry as mostly a parasitic activity that can extract useful information from most of the observations that are taken for other reasons.
		Note that Astrometry needs to measure the positions of all the stars, but it is the color- selected list that should be given to the Pipeline.
	www.astro.princeton.edu /~dss/LSST/lsst-general/msg.87.html (1978 words)

	Astrometry Page
		Astrometry is the science of measuring positions of astronomical objects.
		The most important rule in astrometry is that the accuracy of the observations are as high as possible.This has to be at least better than 1 arc second.
		Doing astrometry does not necessitate the need to know orbital calculations as these are performed at the Minor Planet Center.
	www.geocities.com /sbrincat.geo/metry.htm (377 words)

	[No title]
		The key task of SDSS astrometry is to ensure that the positions of the holes drilled for spectroscopic fibers are sufficiently accurate that spectroscopic targets are well-centered on the fibers.
		The relative astrometry between adjacent colors should be no worse than 180 mas on the time-scale over which the relative astrometry is determined.
		A comparison of astrometry from that run with 5555 UCAC star positions show a mean offset in RA of -11 mas, rms of 119 mas, and in DEC 7 +/- 139 mas.
	tdserver1.fnal.gov /project/sdss/dp-review-700/dp-review-docs/astrom.htm (2466 words)

	Astrometry of Asteroids: Introduction (Site not responding. Last check: 2007-10-21)
		astrometry, which is one of the fundamental tools of astronomers.
		Astrometry enables us to make charts of objects in the sky, assigning two numbers or celestial coordinates to each object so that we can easily locate it.
		Still, the method is the same and measuring the parallax of asteroids using astrometry is a useful exercise for showing us how the much smaller parallax of stars is measured in practice.
	www.astro.lsa.umich.edu /Course/Labs/asteroids/intro.htm (2115 words)

	SOHO Astrometry Files
		Astrometry measurements are made on the SOHO (LASCO only) images via fairly simple 'point-and-click' software.
		All of the images in which the comet is visible are loaded, and in each image the comet is identified and marked.
		The astrometry files contain positional information on the spacecraft (SOHO), the object (comet) and a selection of bright stars from the image, as well as the time and date.
	ares.nrl.navy.mil /sungrazer/TXTS/iau_expl.html (643 words)

	Astrometry and photometry (Site not responding. Last check: 2007-10-21)
		Astrometric and photometric data are used in all branches of astronomy: the planetary system, structure and evolution of stars, structure and evolution of the Milky Way as well as in cosmology and extragalactic astronomy.
		Astrometry and photometry have become strongly coupled after the introduction of linear detectors in astrometry.
		A red survey to declination +60° with the Carlsberg Meridian Telescope on La Palma in collaboration with the Spanish Royal Institute and Observatory of the Navy and the Institute of Astronomy, Cambridge, UK.
	www.astro.ku.dk /research/astrometry2.html (298 words)

	IAU Commission 8 Astrometry (Site not responding. Last check: 2007-10-21)
		Original Commission 24 "Stellar Parallaxes" was first renamed to "Stellar Parallaxes and Proper Motions" then to "Photographic Astrometry" but in 2000 it merged with the former Commission 8 to form the present Commission 8.
		The IAU Commission 8 "Astrometry" coordinates all aspects of positional astronomy which involve positions, proper motions, and parallaxes of celestial objects.
		Currently, one of the main tasks is to ensure a smooth implementation of the IAU 2000 resolutions aimed at realization of a sub-microarcsecond astrometry.
	www.pha.jhu.edu /iau_comm8/comm8.html (156 words)

	MAPS - Documentation - Astrometry
		However, the final accuracy of any astrometry also depends on the quality of the plates, the centroiding algorithm, and the accuracy and density of the astrometric reference catalogs used.
		By examining the regions where plate pairs overlap, as well as the positions on the O and E exposures of a given field, we have established that APS object positions are locally accurate to an rms of 0:00.2.
		APS astrometry is done in three steps which overcome these problems and obtain a good full-plate astrometric solution.
	isis.spa.umn.edu /docs/astrometry (1076 words)

	Photometry/Astrometry from 2MASS Quicklook Images
		Astrometry and photometry obtained from the Quicklook images are not as accurate as that inherent to the 2MASS Point Source Catalog, which were derived from the uncompressed, stacked raw images.
		Therefore, the astrometry derived from the images and that contained in the 2MASS Point Source Catalog can systematically vary by up to ± 0.2 arcsec offset as a function of pixel position in the image.
		To assess the accuracy to which quantitative infromation can be extracted from the Quicklook images, point source astrometry and aperture photometry was performed on 5 such images and compared with values tabulated in the final 2MASS Point Source Catalog.
	www.astro.caltech.edu /~jmc/2mass/v3/quicklook (1094 words)

	Follow-up astrometry (Site not responding. Last check: 2007-10-21)
		We are engaged in follow-up astrometry of newly discovered NEOs, poorly observed NEOs in further apparitions, recoveries of NEOs, newly discovered comets, Centaurs.
		The 2004 statistics shows that the Klet' Observatory was the third world most prolific professional site/observatory producing astrometry of NEAs published in Minor Planet Electronic Circulars (the LINEAR project was the first) and the Klet Observatory was the first in Europe.
		The 2003 statistics shows that the Klet' Observatory was the second world most prolific professional site/observatory producing astrometry of PHAs and NEAs published in Minor Planet Electronic Circulars, the LINEAR project was the first.
	www.klet.org /foll.html (1003 words)

	How to do astrometry
		Accurate astrometric measurements of the position of an object, an asteroid for example, have as a goal the determination of the sky coordinates of that object.
		Steps 3 and 4 can be accomplished using the astrometry calculator, a javascript program I supply as part of the SIP project (look under "Astrometry" on the left side of the SIP homepage).
		astrometry calculator, a javascript program I supply as part of the SIP project (look under "Astrometry" on the left side of the SIP homepage), will determine the x,y-to-Ra,Dec transformation for your image, and determine the RA,Dec coordinates of your object.
	www.phys.vt.edu /~jhs/SIP/astrometry.html (1725 words)

	Improving absolute astrometry
		memo on astrometry problems to see if your dataset is affected by offsets introduced by processing errors or use of non-standard fiducial lights.
		The aspect pipeline software design and flight performance (as of February 2000) are described in a paper presented at the SPIE meeting on Astronomical Telescopes and Instrumentation 2000.
		The key result for astrometry is that the celestial location accuracy for HRC is currently about 0.6 arcsec (RMS radial offset).
	asc.harvard.edu /mta/ASPECT/improve_astrometry.html (952 words)

	Astrometry - Scientia Astrophysical Organization
		Astrometry can be considered the oldest sub-field of science and has been important in history for sailing (maritime navigation), since navigators used to calculate their position on Earth upon the observation of stars.
		Positional astrometry was only qualitative in its earliest days.
		A very important work that used both astrometry and astrophysics was made by Edwin Hubble.
	www.astrometry.org /astrometry.php (426 words)

	Alibris: Astrometry
		Fundamentals of astrometry at milli- and micro-arcsecond accuracies.
		Presently, positional astrometry is at the watershed between classical fundamental catalogues, based on moving reference stars, and modern catalogues, based on extragalactic reference objects with non-measurable motion.
		IAU Colloquium 165, Dynamics and Astrometry of Natural and Artificial Celestial Bodies, was held in Poznan, Poland, in July 1996, bringing together over 200 scientists from 27 countries who discussed their work in 179 oral and poster presentations.
	www.alibris.com /search/books/subject/Astrometry (716 words)

	Some Other Astrometry Sites (Site not responding. Last check: 2007-10-21)
		Astrometry is that branch of astronomy in which positions and motions of the Sun, Moon, planets and selected stars are precisely determined.
		The field of astrometry has undergone a rebirth, as of late, and has once again assumed an influential role within many fields of astronomy.
		Hipparcos was a space experiment dedicated to the precise measurement of the positions, parallaxes and proper motions of the stars.
	clyde.as.utexas.edu /SpAstNEW/AST1.html (230 words)

	Siding Spring Survey Follow-up Obs
		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).
		The astrometry is done with both Bill Gray's CHARON, which although DOS based is extremely fast and Herbert Raab's Astrometrica which has an excellent track and stack option.
		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!
	msowww.anu.edu.au /~rmn/follow-u.htm (848 words)

	Improving the Astrometry of your Data - CIAO 3.3
		It is also possible to obtain absolute astrometry which is accurate to 0.1" - 0.2" by using optical, radio, and/or IR source positions.
		Apply an offset for improved astrometry: if the X-ray observation has point sources with very accurately known optical/radio/IR counterpart positions, it is possible to obtain absolute astrometry which is accurate to 0.1" - 0.2".
		In this case, it is up to the user to calculate the offsets (delta RA and delta Dec) with respect to the cataloged position.
	cxc.harvard.edu /ciao/threads/arcsec_correction (1184 words)

	Setting Up Astrometry
		specifies type of astrometry execution, wheather it is performed in synchronous mode, which means frames is taken and astrometry performed or
		in asynchronous astrometry mode sometimes normal-synchro version is called (for example after position change), but in case failed
		Astrometry is saved in fits header and can be used off-line without
	info.fuw.edu.pl /~msok/SettingUpAstrometry.html (508 words)

	WvA.ResearchInt.html
		Research interests in Astrometry at Yale lie primarily in the fields of absolute and relative proper motions, stellar parallaxes, binaries and instrumentation to improve the accuracy of astrometric observations with applications to Star Clusters, Galactic Structure, and Space Astrometry.
		His HST research has been primarily directed towards the determination of parallaxes of the Hyades Cluster and various astrophysically interesting stars, as well as determination of the internal motions of several Globular Clusters based on first and second exposures (1992 to 2000) that we have taken with the WFPC and WFPC2 cameras on HST.
		These proper motions will be used to measure the internal velocity dispersions as functions of distance from the cluster center and stellar mass, and to study the degree of anisotropy and, in comparison with independently determined radial velocities, the kinematic distances to the clusters.
	www.astro.yale.edu /astrom/WvA.Research.html (1360 words)

	A Science Case for Pulsar Astrometry (Site not responding. Last check: 2007-10-21)
		True ages of both pulsars and their associated SNRs may also be estimated (or constrained) from the angular separation of the SNR and pulsar, and the pulsar proper motion.
		Similarly, accurate astrometry allows some pulsars to be traced back to their birth sites in stellar clusters (e.g.
		Nuclear Astrophysics: Accurate distance measurements, in combination with observed thermal radiation from the neutron star surface, can be used to constrain the `size' of the neutron star photosphere, with important implications for the NS Equation of State.
	astrosun.tn.cornell.edu /~shami/psrvlb/science.html (671 words)

Try your search on: Qwika (all wikis)