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Close Up of Ancient, White Dwarf Stars in the Milky Way Galaxy
About the Object
- R.A. PositionR.A. PositionRight ascension – analogous to longitude – is one component of an object's position.16h 23m 35.4s
- Dec. PositionDec. PositionDeclination – analogous to latitude – is one component of an object's position.-26° 31' 31.9"
- ConstellationConstellationOne of 88 recognized regions of the celestial sphere in which the object appears.Scorpius
- DistanceDistanceThe physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs.M4 is roughly 5,600 light-years from the Earth.
- DimensionsDimensionsThe physical size of the object or the apparent angle it subtends on the sky.1 light-year across
About the Data
- Data DescriptionData DescriptionProposal: A description of the observations, their scientific justification, and the links to the data available in the science archive.
Science Team: The astronomers who planned the observations and analyzed the data. "PI" refers to the Principal Investigator.WFPC2 data Principal Astronomers: H. Richer (UBC), D. Vandenberg (U.Victoria), P. Stetson (DAO), M. Bolte (UCSC/Lick Obs.), C. Pryor (Rutgers U.), R. Mcclure (DAO), J. Hesser (DAO), G. Fahlman (CFHT), H. Bond (STScI), R. Bell (U. Maryland) STIS data Principal Astronomers: H. Richer (U. British Columbia), G. Fahlman (CFHT), B. Gibson (U. Colorado), B. Hansen (Princeton U.), R. Ibata (ESO), M. Limongi (Osservatorio Astronomico di Roma), M. Rich (UCLA), M. Shara (AMNH), P. Stetson (DAO) - InstrumentInstrumentThe science instrument used to produce the data.HST>WFPC2 and HST>STIS/MULTIACCUM
- Exposure DatesExposure DatesThe date(s) that the telescope made its observations and the total exposure time.February - March 1995, Exposure Time: 1.2 days (WFPC2), and January - April 2001, Exposure Time: 7.4 days (STIS)
- FiltersFiltersThe camera filters that were used in the science observations.F336W (B), F555W (V), F814W (I)
- Object NameObject NameA name or catalog number that astronomers use to identify an astronomical object.M4, NGC 6121
- Object DescriptionObject DescriptionThe type of astronomical object.Globular Cluster, White Dwarf Stars
- Release DateApril 24, 2002
- Science ReleaseHubble Uncovers Oldest “Clocks” in Space to Read Age of Universe
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Claire Andreoli
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
claire.andreoli@nasa.gov
