Hubble Measures Deflection of Starlight by a Foreground Object

 Hubble Measures Deflection of Starlight by a Foreground Object

How Gravity Can Bend Starlight

This illustration reveals how the gravity of a white dwarf star warps space and bends the light of a distant star behind it.

White dwarfs are the burned-out remnants of normal stars. The Hubble Space Telescope captured images of the dead star, called Stein 2051 B, as it passed in front of a background star. During the close alignment, Stein 2051 B deflected the starlight, which appeared offset by about 2 milliarcseconds from its actual position. This deviation is so small that it is equivalent to observing an ant crawl across the surface of a quarter from 1,500 miles away. From this measurement, astronomers calculated that the white dwarf's mass is roughly 68 percent of the sun's mass.

Stein 2051 B resides 17 light-years from Earth. The background star is about 5,000 light-years away. The white dwarf is named for its discoverer, Dutch Roman Catholic priest and astronomer Johan Stein.

Credits

NASA, ESA, and A. Feild (STScI)

About The Object
Object Name Stein 2051 B, WD 0426+588
Object Description White dwarf star
R.A. Position 04h 31m 13s
Dec. Position +58° 58' 41"
Constellation Camelopardalis
Distance 17 light-years (5.5 parsecs)
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.