Stellar Alignment Yields White Dwarf's Mass
Looks can be deceiving. In this Hubble Space Telescope image, the white dwarf star Stein 2051 B and the smaller star below it appear to be close neighbors. The stars, however, reside far away from each other. Stein 2051 B is 17 light-years from Earth; the other star is about 5,000 light-years away.
Astronomers made the Hubble observations of the white dwarf, the burned-out core of a normal star, and the faint background star over a two-year period. Hubble observed the dead star passing in front of the background star, deflecting its light. During the close alignment, the distant starlight 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 is named for its discoverer, Dutch Roman Catholic priest and astronomer Johan Stein.
Credits
NASA, ESA, and K. Sahu (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 Data | |
| Data Description | The image was created from Hubble data from proposals and P.I. K. Sahu (STScI). |
| Instrument | HST>WFC3/UVIS |
| Exposure Dates | Oct. 2013 - Oct. 2015 |
| Filters | F606W (wide V), F814W (I) |
| About The Image | |
| Color Info | This image is a composite of separate exposures acquired by the WFC3/UVIS instrument on the Hubble Space Telescope. Two filters were used to sample different 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 and orange F814W. |
| Compass Image |  |
| 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 |
|
| 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. |
