This artist's illustration shows how the gravity of a foreground white dwarf star warps space and bends the light of a distant star behind it. Astronomers using NASA's Hubble Space Telescope have for the first time directly measured the mass of a single, isolated white dwarf (the surviving core of a burned-out Sun-like star) – due to this optical trick of nature. The greater the temporary, infinitesimal deflection of the background star's image, the more massive the foreground star is. (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.) Researchers found that the dwarf is 56 percent the mass of our Sun.
This effect, called gravitational lensing was predicted as a consequence of Einstein's theory of general relativity from a century ago. Observations of a solar eclipse in 1919 provided the first experimental proof for general relativity. But Einstein didn't think the same experiment could be done for stars beyond our Sun because of the extraordinary precision required.
Credits
Artwork
NASA, ESA, Ann Feild (STScI)
| About The Object | |
|---|---|
| Object Name | LAWD 37 (LP 145-141) |
| Object Description | Isolated White Dwarf |
| R.A. Position | 11:45:42.9205 |
| Dec. Position | -64:50:29.459 |
| Constellation | Musca |
| Distance | About 15 light-years |
| 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. |
