Globalization of stellar data:Globalization of stellar data:all-sky catalogues and open clusters all-sky catalogues and open clusters

A.E. Piskunov1 and N.V. Kharchenko2

1Institute of astronomy RAS, Moscow, Russia2Main astronomical observatory, Kiev, Ukraine

Contents

1.Astronomical data globalization

principles practice achievements

2.Open clusters and data globalization

Pre-Hipparcos status and current activity Our project ASCC OC as example

3.Prospects

1.1. Globalization of stellar data: principles

All-sky coverage

Completeness and high resolution at some depth

Uniformity of data structure over the sky

High precision Homogeneity of stellar data systems over all sky

Accessibility

1.2. Realization of the celestial system as a major aspect of the globalization

Realization of all-skycoordinate & photometric systems:

Hipparcos/Tycho missions

Extension of the systems to fainter stars:

High precision measuring machinesautomated telescopes

Hipparcos family

HipparcosTycho-2

ASCC-2.5

Schmidt surveys:GSC

USNOSSS

Array detector surveys:2MASSUCAC

1.3. Examples of practical data globalization.

Example 1: present-day all-sky catalogues

Catalogue

Numberof stars,

mln

RA,Decerror,mas

Proper motions Stellar magnitudes

Error, mas/yr

Complete-ness, % Band

Error,mmag

Limit,mag

Complete-ness, mag

Hipparcos 0.12 0.7 - 2 0.8 - 2 98 Hp, B, V 3 - 10 12.4 7.5

Tycho2 2.5 7 -60 2 - 6 97 BT , V T 10 - 100 15.0 11.5

ASCC-2.5 2.5 0.7 - 60 0.8 - 20 100 B, V 3 - 100 15.0 11.5

GSC II 998 300 10 ? B, R, I 400 18 ?

USNO-A2.0 526 250 - - B, R 300 22 18

USNO-B1.0 1046 200 15 - 70 30 B, R, I 300 22 19

SSS (1000) 200 10 - 50 65 B, R, I 40-200 22 (19)

UCAC2 48(80) 20-40 1 -5 100 R + J,H,K 300 16.5 (14)

2MASS 471 100 - - J,H,K+B,R 15 - 200 17 - 14.3 15 - 12

USNO-B1.0 USNO-B1.0 (with PM)USNO-A2.0 UCAC2

2MASS UCAC2

1.4. Practical globalization. Example2: brightness distribution

ASCC-2.5

UCAC2

2MASS and

UCAC2(black points)

SSS

USNO-B1.0 and

USNO-A2.0(black points)

1.5. Practical globalization. Example 3: CMD diagrams

1.5. Practical globalization.

Example 4: proper motions

UCAC2

ASCC-2.5

USNO-B1.0 and SSS (black)

2.0 Open clusters and data globalization

in the pre-Hipparcos era in the post-Hipparcos era

Dias et al. (on-line): compilation of about 1700 open cluster data;

Platais et al. 1998: 15 new clusters/stellar groups, Hipparcos;

Alessi et al. 2003, 2004: 11+~50 new clusters, Tycho-2;

Bica et al. 2003:~350 new IR candidates of clusters/stellar groups, 2MASS;

Drake (2005): 7 candidates of clusters, USNO-A2;

Kharchenko, Piskunov et al. 2005:parameters of 520 known and 130 new clusters, ASCC-2.5 (the sample is complete up to 850 pc);

Kumar et al.(2006): over 60 candidates of embedded clusters in 2MASS;

Kronberger et al. (2006): 24 candidates from DSS images analysis.

A total of 1200 clusters known by 1988 (Lynga , Lund Catalogue rel.5);

For about 1200 clusters apparent diameters (eye-estimated from POSS charts or defined by the size of detector FOV) were given;

About 400 clusters had accurate, but heterogeneous UBV photometry, distance, reddening, age;

Kinematics: heterogeneous proper motions and RVs. Less than 100 clusters with PM in FK4 and RV. The 3-d velocities are available for a few tens of clusters only;

No idea on the degree of completeness in cluster statistics;

No way to study the population of stellar associations, extended clusters and loose groups (except nearby OB associations).

2.1.Open cluster specifics and all-sky catalogues

Successful search/study of various issues of open clusters requires:

Object list completeness in dense sky areas

Multi dimensionality of data (variety of data types)KinematicsPhotometrySupplementary data

Data sufficiency for all clusters:Coordinates, PM, 2color photometry 100 %VR, Sp.Classes/3 color photometry (reddening) 10 %

High data accuracy over full magnitude range

2.2. Open clusters: practice of globalization(ASCC OC project)

The Sample:513 known clusters 7 known associations130 newly detected clusters 2 large nearby clusters

Cluster parameters:combined (PM,XY,CMD)membershipcoordinatescore & corona radiiPM,VRdistances, reddeningages

The sources:All-sky compiled catalogue

ASCC-2.5 (v.3)2.5 mln. Johnson B,V and PM

0.5 mln. Spectral Classes46,0000 RVs

and Literature data

The results:

The methods:Identification of known clusters

Detection of new clusters

Membership pipeline

Cluster parameter determination

The input:

.

2.3. Open clusters: summary of the ASCC OC project

NEW UNIFORMSCALES ofCLUSTER

ParameterPreviously

knownRevised orconfirmed

Newdetermination

out of 1700 out of 520 out of 650

MEMBERSHIP Combined probability -- -- 38463

STRUCTURE Size 1700 515 135

PHOTOMETRY Distance & reddening 760 320 330

KINEMATICS Proper Motion 458 219 431

Radial Velocity 258 159 163

EVOLUTION Age 637 325 325

.

2.4. ASSC OC data incompleteness: Radial Velocity

Completeness limit 850 pc

Density enhancement

552 clusters

~800 missing clusters

Background level

552 clusters

2.5. ASCC OC sample: spatial completeness

2.6. Open clusters: 2D distribution in the disk

D0 1015 kpc-3

114 kpc-2 (5 times larger!)

Predicted number of OC for R

G=15 kpc

100,000

Spiral pattern :Grand design with pitch angle=-6°

2.7. Cluster complexes:tangential velocity VPDs the general environment

OCC-1 OCC-2Perseus-Auriga

Hyades

log t < 7.9 log t = 8.3...8.6

log t = 7.9...8.3log t > 8.6

Extinction map a

V = A

V / d

Blue triangles - OCC-1 Red circles – OCC-2Magenta diamonds - Perseus-Auriga groupBlack crosses - Hyades moving groupSmall circles - “field” clusters

P=1/ – decay probability a – cluster age, a = t

1 – t, t

1 ⇒ present, t ⇒ at birth

– rate of cluster formation N(a) = (t

1-a) e -a/

t1/2

⋲ 0.7

= 364±32 Myr

= 0.24± 0.02 1/Myr

Literature:

= 140-240 Myr

= 0.1-0.25 1/Myr

All clustersComplete sampleWielen 1971

2.8 Open clusters: ages and lifetime

3.1. Further steps Developing the success on available data basis

Further exploration of current resources: ASCC: new cluster parameters: segregation, tidal radii, massesUCAC: new clusters & new cluster parameters, 2MASS: new clusters & new cluster parameters,

Extending photometry basis:

ASCC+2MASS: ASCC cluster sample increase by 15%

Extending accurate Proper Motion space dimension:

AC+2MASS: ASCC cluster sample increase by >50%

Extending Radial Velocity space dimension:

ASCC+RAVE: 25% increase of the RV sample

3.2. Quality leap: waiting for GAIA

Current resources unable to provide completeness in:

data (RVs, extinction/distances/ages) for more than 2/3 of known OCs

space beyond 1 kpc-neighbourhood (effectively beyond Sagittarius and Perseus spiral arms)

DIVA: good, but lost opportunity

GAIA: the only but far-away opportunity