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ON-LINE SERVICES AT CDS FOR DISTRIBUTION OF HIPPARCOS DATA

D. Egret, F. Ochsenb ein, F. Genova

CDS, Observatoire astronomique de Strasb ourg, 67000 Strasb ourg, France

This is done through the development of a set of com- ABSTRACT

plementary information services see e.g. Egret et al.

1995, Genova et al. 1996.

CDS has b een implementing the following functional-

ities for a timely distribution of Hipparcos and Tycho

The common gateway to all these services is

pro ducts, when they are released, in June 1997:

the CDS home page on the World-Wide Web at

http://cdsweb.u-strasbg.fr/

1. Access will be given to the Hipparcos cata-

We describ e here how these services can b e used for

logues ESA 1997 through the VizieR catalogue

gaining access to Hipparcos and Tycho data and cat-

browser, allowing queries byany of the catalogue

alogues.

elds. A frequent use of the system will b e the

extraction of Hipparcos or Tycho records related

to a given area of the sky, de ned by its co ordi-

nates or by the name of a central ob ject this last

2. ACCESS TO INDIVIDUAL RECORDS

functionality making use of the SIMBAD name

THROUGH RELATIONAL QUERIES

resolver.

2. Access will be given to Hipparcos result cata-

logues through the `Astronomer's Bazaar' ftp

Access to Hipparcos and Tycho data will rst be

access to the complete les. The system sup-

provided through the new `VizieR' catalogue service

p orts the transfer of compressed les in order to

which allows the retrieval of individual data records

optimize use of network bandwidth.

from selections on table columns, or from p osition or

ob ject name.

3. The Hipparcos and Tycho Catalogues will b e in-

cluded within SIMBAD as so on as p ossible after

VizieR Ochsenb ein 1997, the CDS service for astro-

the June 1997 release date. The work has al-

nomical catalogues, is the result of a joint e ort b e-

ready b een prepared with the Input Catalogues;

tween the Strasb ourg astronomical Data Centre and

nevertheless, it will take some time b efore a

the Information Systems Division of the Europ ean

number of inconsistencies are investigated and

Space Agency ESA{ESRIN in order to provide the

solved.

astronomical community with a dedicated to ol for

retrieving astronomical data listed in published cat-

4. The Aladin interactive sky atlas, in its nal de-

alogues and tables.

velopment phase, will also supp ort access to the

Hipparcos and Tycho data for photometric and

astrometric calibration and for overlays on digi-

Access to Hipparcos and Tycho result catalogues

tized sky images.

through VizieR will start with Hipparcos and Tycho

main catalogues, as so on as they are released, and

will also include Annex les for Double and Variable

In the future, as CDS services continue to evolve,

stars and Solar system Annexes. Functionalities in-

more links will b e added b etween these services and

clude selection of individual records, for a given area

the asso ciated bibliographic services, allowing yet

of the sky,orby parameter ranges on any eld. Full

more p owerful supp ort for the usage of Hipparcos or

do cumentation of the catalogues will b e available on-

Tycho data pro ducts.

line.

Example: Extraction of Hipparcos or Tycho records

Key words: Catalogues; CDS.

for stars brighter than 9.0, having go o d astrometric

quality,inagiven area of the sky, de ned by co ordi-

nates or name of a central ob ject this last function-

ality making use of the SIMBAD name resolver.

1. INTRODUCTION

The interface is based on the use of World-Wide Web

forms. The reference numb er for the Hipparcos and

The ob jective of the Strasb ourg astronomical Data

Tycho Catalogues ESA 1997 in the CDS system is

Centre CDS is to provide on-line data and infor-

I/239.

mation for the world-wide astronomical community.

The release date for this service is Tuesday 17 June astronomical ob ject, thus o ering a unique p ersp ec-

1997, at the following address: tive on astronomical data. This is done through a

http://vizier.u-strasbg.fr/ careful cross-identi cation of ob jects from catalogues,

lists, and journal articles. The abilityto gather to-

gether any sort of published observational data re-

lated to stars or galaxies has made SIMBAD a key

3. ACCESS TO THE COMPLETE FILES FOR

to ol used worldwide for all kinds of astronomical

FTP TRANSFER

studies. SIMBAD includes bibliographic references

to pap ers citing the ob jects, thanks to a bibliographic

survey covering the astronomical literature since 1950

Access to all Hipparcos and Tycho result cata-

for stars, and since 1983 for extragalactic ob jects.

logues distributed by ESA on CD-ROMs except

The data base is kept up-to-date on a daily basis, as

Epoch Photometry will b e provided through the `As-

the result of the collab oration of CDS with bibliog-

tronomer's Bazaar'.

raphers in the Institut d'Astrophysique de Paris and

the Paris and Bordeaux observatories Laloe 1995.

The Astronomer's Bazaar Egret & Ochsenb ein 1994

isaWorld-Wide Web service allowing:

In preparation for the release of Hipparcos data, a

sp eci c e ort has b een undertaken at CDS in recent

years to fold into the data base large astronomical

to query the full list of available catalogues and

stellar catalogues, together with their sp eci c identi-

tables, bykeyword, or in browse mo de, in order

ers and measurements, such as the PPM catalogue

the select the relevant les,

Roser & Bastian 1991.

to display the corresp onding do cumentation,

Functionalities include access to cross-identi cation,

and to retrieve the complete electronic les

measurements and complete bibliography for individ-

eventually compressed, in ASCI I or FITS for-

ual ob jects, called by name, or for lists of ob jects

mat, from the anonymous ftp space of the CDS

selected by criteria.

server.

Examples:

More than 2000 catalogues and tables, for a total

of several Gigabytes of data are currently available

Selection of all A-typ e stars observed with the

through this interface.

International Ultraviolet Explorer IUE and

measured by Hipparcos.

Functionalities include the transfer of complete

ASCI I les using the p opular File Transfer Proto-

Search for recent bibliography of all RR Lyrae

col ftp. The system supp orts the transfer of com-

stars observed by Hipparcos.

pressed les in order to optimize use of network band-

width. Flexible Image Transp ort System FITS for-

Several interfaces are available: World-Wide Web

mat may b e generated on the y.

forms, X-Window client, line-by-line command inter-

face.

Warning: some of the les are very large! When

p ossible, CD-ROMs of the Hipparcos mission, dis-

Hipparcos stars can b e found under their HIC or HIP

tributed by ESA, should be preferred, as more ap-

numb ers, Tycho stars under their TYC numb ers.

propriate transfer media, for the large les of the

Hipparcos and Tycho Catalogues.

Release dates: HIC numb ers are already included in

SIMBAD, and consequently integration of HIP stars

The reference numb er for the Hipparcos and Tycho

is approximately 99 p er cent complete. Gradual in-

Catalogues ESA 1997 in the CDS system is I/239.

clusion of Tycho entries will start in June 1997. The

work has already b een prepared with the Tycho In-

The release date for this service is Tuesday 24 June

put Catalogue, and with the cross-identi cation of

1997, at the following address:

the Tycho Catalogue with several ma jor catalogues

http://cdsweb.u-strasbg.fr/Cats.html

see Egret & Fabricius 1997; nevertheless, it will take

some time b efore a numb er of inconsistencies are in-

Mirror copies are also available at the NASA Astro-

vestigated and solved.

nomical Data Center: http://adc.gsfc.nasa.gov,

and at the National Astronomical Observatory in

SIMBAD is available at the following address:

Tokyo: http://adac.mtk.nao.ac.jp

http://simbad.u-strasbg.fr/

4. ACCESS TO COMPLEMENTARY

5. ACCESS TO RELATED IMAGES OF THE

INFORMATION FOR THE OBJECTS

DIGITIZED SKY

The SIMBAD data base is a powerful to ol for pro-

The `Aladin' interactive sky atlas, now in its nal de-

viding complementary information, when available in

velopment phase see e.g. Bonnarel et al. 1997, will

the published literature, for astronomical ob jects ob-

include links to the Hipparcos and Tycho Catalogues.

served by the Hipparcos space astrometry mission.

The sp eci city of the SIMBAD data base see e.g. Aladin is a new pro ject nearing completion which al-

Egret et al. 1991 is to organize the information p er lows the user to visualize on his/her own workstation

digitized images of any part of the sky,tooverlay en- REFERENCES

tries from astronomical catalogues or user data les,

and to interactively access the related data and in-

Bonnarel, F., Ziaeep our, H., Bartlett, J.G., et al.

formation from the SIMBAD data base for all known

1997, in IAU Symp. 179, New Horizons from

ob jects in the eld.

Multi-Wavelength Sky Surveys, in press

Egret, D., Fabricius, C., 1997, ESA SP{402, this vol-

The data base currently includes the rst Digitized

ume

Sky Survey DSS-I pro duced by the Space Telescop e

Egret, D., Ochsenb ein, F., 1994, CDS Inform. Bull.,

Science Institute, covering the complete sky,asaset

44, 57

of slightly compressed images. Images of the second

epoch survey DSS-I I; Lasket et al. 1996 are grad-

Egret, D., Wenger, M., Dub ois, P., 1991, in

ually b eing included. In addition, high resolution

Databases & On{line Data in Astronomy, Al-

images of crowded regions of the sky e.g. Galactic

brecht & Egret Eds., Kluwer Acad. Publ., 79

Plane and Magellanic Clouds have b een provided by

Egret, D., Cr ez e, M. , Bonnarel, F., et al. 1995, in

the MAMA Machine a Mesurer p our l'Astronomie

Information & On{line Data in Astronomy, Egret

facility at Observatoire de Paris, and by Sup erCos-

& Albrecht Eds., Kluwer Acad. Publ., 163

mos of the Royal Observatory in Edinburgh.

ESA, 1997, The Hipparcos and Tycho Catalogues,

ESA SP{1200

The interface is based on a sp eci c X-Window client

program, to b e installed on the user's site.

Genova, F., Bartlett, J. G., Bienaym e, O., et al. 1996,

Vistas in Astronomy, 40, 429

Currently May 1997, Aladin is only available from

Laloe, S., 1995, Vistas in Astronomy, 39, 259

a limited number of sites; it will eventually b ecome

Lasker, B. M., Doggett, J., McLean, B., et al. 1996,

a public interactive to ol, available through the data

Astronomical Data Analysis Software and Sys-

networks. CDS should be contacted for further de-

tems V, A.S.P. Conference Series, Vol. 101, G.

tails.

H. Jacoby and J. Barnes, eds., 88

Ochsenb ein F., 1997, Baltic Astronomy 6, 221

The Hipparcos and Tycho Catalogues will be avail-

able for overlays on digitized images of the sky.

Roser, S., Bastian, U., 1991, PPM Star Cata-

logue, Volumes I and I I, Astronomisches Rechen-

Institut, Heidelb erg

An example of a use of the Aladin service is the multi-

wavelength cross-identi cation of sources detected in

the X-ray domain, with Tycho stars. Users will also

be able to call the Tycho catalogue for a new pho-

tometric and astrometric calibration of a given area

in order to extract the full information from the dig-

itized plates.

6. FUTURE PERSPECTIVES

In the future, as CDS services continue to evolve,

more links will b e added b etween these services, and

the asso ciated bibliographic information systems, as

well as other distributed archives, allowing yet more

powerful supp ort for the usage of Hipparcos or Tycho

data pro ducts.

In the shorter term, additional to ols for direct and

optimal access to sp eci c subsets of Hipparcos/Tycho

data are b eing considered: they will b e found under

the CDS Web pages.

ACKNOWLEDGMENTS

The Strasb ourg astronomical Data Centre CDS, is

hosted by the Strasb ourg astronomical Observatory,

and funded by the French Institut National des Sci-

ences de l'Univers INSU, CNRS. VizieR has b een

develop ed with the supp ort of the Europ ean Space

Agency. Aladin is b eing develop ed with the supp ort

of the Centre National d'Etudes Spatiales CNES and INSU.