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..-200628 2006

0.2 - 0.5" :

,

FK5 (1535 ) PPM (370 . )

(149 504 312 000 170 400 000) 1960 . (149 540 000 000 13 600 000) 1961 . (149 599 500 000 800 000) 1998 . (149 597 870 691 2) 1999 . (149 597 870 691.0 1.0) 1999 . (149 597 870 691.1 0.2) 1991 . (149 597 870 660 30)

ICRS (ICRF)

CONVENTIONS 2003CHAPTER 1 General Definitions and Numerical StandardsCHAPTER 2 Conventional Celestial Reference FrameCHAPTER 3 Conventional Dynamical Reference FrameCHAPTER 4 Conventional Terrestrial Reference SystemCHAPTER 5 Transformation Between the Celestial and Terrestrial SystemsCHAPTER 6 GeopotentialCHAPTER 7 Displacement of Reference PointsCHAPTER 8 Tidal Variations in UT1CHAPTER 9 Tropospheric ModelCHAPTER 10 General Relativistic Models for Time, Coordinatesand Equations of MotionCHAPTER 11 General Relativistic Models for Propagation

To leap or not to leap?

Classical ICRS Present Day ICRS

ZZXXYYFK5ICRF

ICRF 3273

x,y LOD

:

HIPPARCOSHIgh Precision Parallax COllecting Satellite1989-1993, 1997

HIPPARCOS

, HIPPARCOS

1485 , HIPPARCOS TYCHO. 1996-2000 .

327 22% 127 113 124 53

744 50%

143 139 43 45 371 741 50%

: ICRF HCRF

3D Astrometry

The Milky Way: it's floppy and it changes shape From Hipparcos results on many distant stars, astronomers from Turin Observatory, Italy, and Oxford University, UK, deduce that the disk is slightly warped, like the brim of a hat. What's more, the distant stars are travelling in unexpected directions which, if continued, will change the shape of the Milky Way.

-- (122 ) (HIPPARCOS)

" - "

M = -1.25 - 3.00 lgP Lg r = 0.2(m - M) + 1

HIPPARCOS: -- M = (-1.43+-0.1) - 2.81 lgP (Feast et al. MNRAS v.286, Issue1, pp.L1-L5, 1997)

-- distance moduli: Large Magellanic Cloud 18.70+-0.1, M31 -- 24.77+-0.11--- Hubble constant now need to be decreased by ~10 per cent--- The age of the oldest Galactic globular cluster is ~11 Gyr

, -

"Hipparcos cured a headache for cosmologists," said Michael Feast of Cape Town University, South Africa. "We now judge the Universe to be bigger and therefore older, by about a billion years. The oldest stars are much younger than supposed, by about 4 billion years. If the Universe is about 12 billion years old, everything fits nicely."

Interstellar extinction Stellar seismology Variable Star Distance Scales Post-Hipparcos cosmic candles Confirming a Nobel Prize winning theory with the HIPPARCOS space-craft: Accurately determining distances and diameters of white dwarf stars

Consequences of HIPPARCOS parallaxes for stellar evolutionary models.White Dwarf Magnetic Fields and the Mass-Radius Relation

A new constraint on the theory of stellar nteriors and model atmospheres Interstellar reddening from the HIPPARCOS and TYCHO catalogues.

Fate of the Universe Age of the Universe

Dark Matter

FK6 (1999) FK6 = FK5 + HIPPARCOS 878 : FK6 0.35 mas/y

HIPPARCOS 0.67 mas/y

TYCHO-2 (2000). : TYCHO-1 CUO, USNO, ARI, ESO 2.5 . 2 539 913 : 99% V = 11.0 90% V = 11.5 : 10 mas (V < 9) 100 mas (V < 12) . . : 1.3 mas/y (V < 9) 3.0 mas/y (V < 12)

Astrographic Catalog AC2000.2 4.6 mln stars, 11-13 mag, mean epoch 1907USNO B1. 1 mln stars, complete up V= 21ACR (around equator) 1.3 mln stars, mean epoch 1996.0, complete to V=17GSC2.2, 19 mln stars, up to V=19.5

2MASS( 500 )

S2:

0.05 arcsec (2 light days)

P = 15.2 ya = 5.5 light days Pericenter = 17 light hours (124 AU)V=5 000 km/s

, :

Roemer, FAME, DIVA, , , AMEX

: JASMINE (), OBSS ()

, : Gaia (), SIM ()

DIVA

Deutsches Interferometer frVielkanalphotometrie und AstrometrieDouble Interferometer for Visual Astrometry

:35106 : 15m :17.2m :2 V = 10m:0.2

23 2003

FAME

Full-sky Astrometric Mapping Explorer

: 40106 :5m 15m (V 9m):0.05 (V 15m):0.5

FAME Classic FAME Rescoped

()0.580.84

()2.55

2004?

Gaia Global Astrometric Interferometer for Astrophysics A Stereoscopic Census of our Galaxy

http://www.rssd.esa.int/GaiaMay 2005

Gaia: One Billion Stars Astrometry (V < 20):completeness to 20 mag (on-board detection) 109 starsaccuracy: 10-20 arcsec at 15 mag (Hipparcos: 1 milliarcsec at 9 mag)scanning satellite, two viewing directions global accuracy, with optimal use of observing timeprinciples: global astrometric reduction (as for Hipparcos) Radial velocity (V < 16-17):application:third component of space motion, perspective accelerationdynamics, population studies, binariesspectra: chemistry, rotationprinciples: slitless spectroscopy using Ca triplet (848-874 nm)Photometry (V < 20):astrophysical diagnostics (5 broad + 11 medium-band) + chromaticity Teff ~ 200 K, log g, [Fe/H] to 0.2 dex, extinction

HIPPARCOS and GAIA

Hipparcos

Gaia

Magnitude limit

12

20 mag

Completeness

7.3 9.0

~20 mag

Bright limit

~0

~3-7 mag

Number of objects

120 000

26 million to V = 15



Effective distance limit

1 kpc

1 Mpc

Quasars

None

~5 x 105

Galaxies

None

106 - 107

Accuracy

~1 milliarcsec

4 arcsec at V = 10

10-15 arcsec at V = 15

200-300 arcsec at V = 20

Broad band photometry

2-colour (B and V)

5-colour to V = 20

Medium band photometry

None

11-colour to V = 20

Radial velocity

None

1-10 km/s to V = 16-17

Observing programme

Pre-selected

Complete and unbiased

One Billion Stars in 3-d will Providein our Galaxythe distance and velocity distributions of all stellar populationsthe spatial and dynamic structure of the disk and haloits formation historya rigorous framework for stellar structure and evolution theoriesa large-scale survey of extra-solar planets (~1020,000)a large-scale survey of Solar System bodies (~100,000)

and beyonddefinitive distance standards out to the LMC/SMCrapid reaction alerts for supernovae and burst sources (~20,000)QSO detection, redshifts, microlensing structure (~500,000)fundamental quantities to unprecedented accuracy: to 10-7 (10-3 present)

Planets: Expected DiscoveriesAstrometric survey:monitoring of hundreds of thousands of FGK stars to ~200 pcdetection limits: ~1MJ and P < 10 yearscomplete census of all stellar types, P = 29 yearsmasses, rather than lower limits (m sin i)multiple systems measurable, giving relative inclinations

Results expected:1020,000 planets (~10 per day)displacement for 47 UMa = 360 asorbits for ~5000 systemsmasses down to 10 MEarth to 10 pc

Photometric transits: ~5000?

Gaia: Studies of the Solar SystemAsteroids etc:deep and uniform (20 mag) detection of all moving objects105106 new objects expected (65,000 presently)taxonomy/mineralogical composition versus heliocentric distancediameters for ~1000, masses for ~100orbits: 30 times better than present, even after 100 yearsTrojan companions of Mars, Earth and VenusKuiper Belt objects: ~300 to 20 mag (binarity, Plutinos)

Near-Earth Objects: Amors, Apollos and Atens (442, 455, 75 known today) ~1600 Earth-crossers >1 km predicted (100 currently known)detection limit: 260590 m at 1 AU, depending on albedo

Satellite and System Mass: 1700 kg (payload 800 kg) Power: 2000 W (payload 1200 W) ESA only mission Launch date: 2011 Lifetime: 5 years Launcher: Soyuz Orbit: L2 Ground station: Perth or Madrid Data rate: 1 Mbps

ScheduleCatalogue200020042008201220162020 AcceptanceTechnology DevelopmentDesign, Build, TestLaunchObservationsAnalysisEarly DataConcept & Technology Study ESA SCI 2000(4)Re-Assessment: Ariane SoyuzTo L2Assumed start of Phase B2

SIM

Space Interferometry Mission2009 : (1020)103 :20m :5 :7.5 :3 (V = 8m):

SIM PlanetQuest will: search for terrestrial planets around nearby stars, and measure planetary masses characterize the orbital ellipticity and inclination of multiple-planet systems, to determine the stability and the evolution of planetary systems search for Solar System analog systems with giant planets at 5-10AU investigate formation and migration scenarios that might explain the puzzling presence of hot Jupiters in very short-period orbits

O R I G I N A N D D E S T I N Y O F S T A R SSIM will: Associate stars with their sites of formation to advance studies of their evolution Assist in measuring the masses and luminosities of compact stellar remnants Probe the formation of binary stars

Comparison of SIM with GAIA GAIA's strength is in numbers. The mission will survey ~1 billion stars, with both astrometric and radial velocity measurements. GAIA is a global astrometric mission, with a goal of ~16 as at 15 mag. At 18 mag the accuracy falls to ~200 as whereas SIM will still be capable of 6 as accuracy

For astrometry of extragalactic targets, at 18 mag SIM's advantage is very large, similar to its advantage for planet search. http://www.rssd.esa.int/index.php?project=GAIA&page=Info_sheets_accuracy

What is JASMINE JASMINE is Japan Astrometry Satellite Mission for INfrared Exploration

JASMINEWe plan the infrared space astrometry(JASMINE) project in Japan. JASMINE is a scanning astrometric satellite and will measure parallaxes, positions, and proper motions with the precision of 10 arcsec at z=15.5 mag(z-band: 0.9m). JASMINE can observe a few hundred million stars belonging to the Galactic disk and bulge components which are hidden by the interstellar dust extinction in optical bands. It will be launched in around 2014 and the orbit will be the Lissajous orbit around the Sun-Earth L2 point with 5 years mission life. As for the payload, we adopt the 3-mirrors optical system(modified Korsch system) with the primary mirror of 2m diameter and 66.7m focal length. The beam combiner should be used for achievement of the global astrometry as used in the HIPPARCOS satellite. On the astro-focal plane, we put about 160 CCDs in which TDI mode(drift scan mode) can be operated. The effective filed of view is 0.23 square-degree. The main scientific objective of JASMINE is to study the fundamental structure and evolution of the Galactic disk and bulge. Furthermore its important objective is to investigate dark matters in small scales, stellar physics, exploration of other planet systems, gravitational lens objects, verification of the general relativity, etc.

"OSIRIS"

The Institute ofAstronomy ofthe Russian Academy ofSciences proposed the project ofaspace mission intended for measurements ofcoordinates ofstars. The expected accuracy will beabout 10micro arcseconds, that ahundred times exceeds accuracy ofground observations and while achieved inspace. Such measurements will allow ustodetermine distances uptoany stars inthe Galaxy and its vicinities. Besides, the reference inthe Universe will bespecified- the metrological basis ofall researches ofthe environmental world. The offered instrument isbased onthe principle ofoptical interferometry.The Optical Stellar Interferometer "OSIRIS" is the only astrometric device under development that will provide the microsecond precision of a single measurement.

, , ,

Great Accuracy In Astrometry - GAIAGreat Advances In Astrophysics - GAIA

3C273 600 (2 . ) The bulging center of our Milky Way Galaxy, dark cosmic clouds, the thin galactic plane, and even nearby galaxies are easy to spot in this sky view. But each pixel in the digital image is actually based on star counts alone -- as derived from the Two Micron All Sky Survey (2MASS) database. In 2001, the 2MASS project completed a ground-based survey of the entire sky and cataloged upwards of 250 million stars. Their full all-sky picture assigns a brightness and color to individual pixels based on corresponding star counts in each of the survey's three near-infrared bands. In this cropped image, the star-packed galactic center is toward the upper left, with the bright plane of our Galaxy running horizontally through it. Dense regions of interstellar dust clouds, still opaque to penetrating near-infrared light, appear dark by reducing the 2MASS star counts. Our fuzzy neighboring galaxies, the large and small Magellanic Clouds, are at the lower right, while scattered single bright spots correspond to the intense concentrations of stars in the Milky Way's large globular star clusters. 2MASS used two highly-automated 1.3-m telescopes, one at Mt. Hopkins, AZ, and one at CTIO, Chile. Each telescope was equipped with a three-channel camera, each channel consisting of a 256256 array of HgCdTe detectors, capable of observing the sky simultaneously at J (1.25 microns), H (1.65 microns), and Ks (2.17 microns

Explanation: Are the nearest galaxies distributed randomly? A plot of over one million of the brightest "extended sources" detected by the Two Micron All Sky Survey (2MASS) shows that they are not. The vast majority of these infrared extended sources are galaxies. Visible above is an incredible tapestry of structure that provides limits on how the universe formed and evolved. Many galaxies are gravitationally bound together to form clusters, which themselves are loosely bound into superclusters, which in turn are sometimes seen to align over even larger scale structures. In contrast, very bright stars inside our own Milky Way Galaxy cause the vertical blue sash. Position Reconstruction Error 0.5"

The center of our Galaxy is a busy place. In visible light, much of the Galactic Center is obscured by opaque dust. In infrared light, however, dust glows more and obscures less, allowing nearly one million stars to be recorded in the above photograph. The Galactic Center itself appears on the right and is located about 30,000 light years away towards the constellation of Sagittarius. The Galactic Plane of our Milky Way Galaxy, the plane in which the Sun orbits, is identifiable by the dark diagonal dust lane. The absorbing dust grains are created in the atmospheres of cool red-giant stars and grow in molecular clouds. The region directly surrounding the Galactic Center glows brightly in radio and high-energy radiation, and is thought to house a large black hole.

Explanation: Why are these stars moving so fast? Shown above is a time-lapse movie in infrared light detailing how stars in the central light-year of our Galaxy have moved over the past eight years. The yellow mark at the image center represents the location of a peculiar radio source named Sgr A*. If these fast stars are held to the Galactic Center by gravity, then the central object exerting this gravity must be both compact and massive. Analysis of the stellar motions indicates that over one million times the mass of our Sun is somehow confined to a region less than a fifth of a light-year across. Astronomers interpret these observations as strong evidence that the center of our Galaxy is home to a very massive black hole.

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