Draco Dwarf Spheroidal

A team of astronomers analyzed observations by NASA's Hubble Space Telescope taken over a span of 18 years to measure the dynamic motions of stars within the Draco dwarf galaxy. The telescope's extensive baseline and data archive enabled the team to build the most accurate three-dimensional map of the stars' movements within the system. These improved measurements are helping to shed "light" on the mysterious qualities and behavior of dark matter, the universe's invisible "glue."

About The Object
Object Name	Draco Dwarf Spheroidal
Object Description	Dwarf spheroidal galaxy
R.A. Position	17:20:12.4
Dec. Position	+57:54:55
Constellation	Draco
Distance	260,000 light-years
Dimensions	Wide field image is 1 degree across (about 4,500 light-years) Inset images are about 3 arcmin across (about 226 light-years)
About The Data
Data Description	The HST observations include those from program (R. van der Marel) and program (S.T. Sohn). Image Processing: Joseph DePasquale (STScI)
Instrument	WFC3, ACS
Exposure Dates	October 2013, October 2022
Filters	F606W, F814W
About The Image
Color Info	These images are a composite of separate exposures acquired by the WFC3/UVIS and ACS instruments on the Hubble Space Telescope. Several filters were used to sample various wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Cyan= F606W, Orange= F814W

About The Object
Object Name	A name or catalog number that astronomers use to identify an astronomical object.
Object Description	The type of astronomical object.
R.A. Position	Right ascension – analogous to longitude – is one component of an object's position.
Dec. Position	Declination – analogous to latitude – is one component of an object's position.
Constellation	One of 88 recognized regions of the celestial sphere in which the object appears.
Distance	The 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.
Dimensions	The physical size of the object or the apparent angle it subtends on the sky.
About The Data
Data Description	Proposal: 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.
Instrument	The science instrument used to produce the data.
Exposure Dates	The date(s) that the telescope made its observations and the total exposure time.
Filters	The camera filters that were used in the science observations.
About The Image
Image Credit	The primary individuals and institutions responsible for the content.
Publication Date	The date and time the release content became public.
Color Info	A brief description of the methods used to convert telescope data into the color image being presented.
Orientation	The rotation of the image on the sky with respect to the north pole of the celestial sphere.

Credits

Science

Image Processing

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