By studying a pulsar doggedly for over two year’s time using the Very Long Baseline Array (VLBA), astronomers in the U.S. and around the world have collaborated to investigate a dim and difficult to detect star approximately 900 light years away from planet Earth. As a result, teams have shared in a unique find, the discovery of an Earth-sized diamond. The star, a white dwarf, was discovered almost exclusively in part to a tag-along pulsar that allowed astronomers to spot the burned out star.
White dwarfs are very dense, end-of-phase versions of a star. Many of these have collapsed to form an object that is roughly the size of a planet over time. White dwarfs cool and fade over the course of a billion years, and are composed primarily of carbon and oxygen. The cooled, crystallized carbon of the collapsed star would look, experts explain, not unlike a diamond. A graduate student and astronomer who aided in the cooled star’s discovery explains that what researchers should have seen while monitoring the pulsar was a white dwarf approximately 10 times fainter than any other ever documented, but there was no visual on the find initially. This led astronomers to the hypothesis that the white dwarf must be unusually cold. Their speculation was right.
Pulsars are the extremely dense leftovers of enormous supernovas, or stars that have exploded. Neutron stars, which spin rapidly, stream large radio waves. Using these radio waves, a former graduate student of West Virginia University and a team of astronomers have discovered what appears to be the most cooled and faintest white dwarf star to be detected, which is ostensibly a diamond the size of planet Earth. James Boyle, as well as University of Wisconsin-Milwaukee professor David Kaplan and company, discovered this space gem using the National Radio Astronomy Observatory’s Green Bank Telescope and the Very Long Baseline Array.
This exhausted star has a mass that is recorded as 1.2 times greater than this solar system’s Sun. Its companion pulsar has a mass of 1.05 times that of our Sun. This, the coolest white dwarf recorded in the history of space observation, has a temperature that astronomers speculate may be 5,000 times cooler than the Sun (at around 2,700 degrees Celsius). Researchers applied Einstein’s theory of relativity to the study of the two planetary sized objects. Astrologists have determined that the gravity of the pulsar, spinning rapidly around its host, warped the space around and distorted the dwarf’s radio signals, obscuring the reading of the dwarf star. Scientists analyzed this data at length to determine the direction of the duo’s orbit, as well as the mass of the objects.
This particular white dwarf is estimated to be over 11 billion years in the making. Scientists postulated that the only way a star would be invisible at this one’s projected distance to Earth was if it had already managed to cool enough to appear “dead,” and would be in that case already crystallized. While assuming that the pulsar was zipping along with a ghost star companion might sound like a stretch, this explanation sounded much more likely to researchers at the time than the alternative: if the interruption in the radio waves weren’t from a planet-sized gem, then that would mean that the accompanying white dwarf would actually pre-date the Milky Way galaxy. (This is, in laymen’s terms, extremely unlikely, and would mean that the dwarf and pulsar in effect pre-dated the solar system.) This pulsar, spinning over 30 times each second, is identified as PSR J2222-0137. This pulsar is the only thing which allowed for the discovery of one of the coolest, faintest white dwarf stars ever to be detected. It has been estimated that the two objects orbit one another roughly every 2.5 days.
The earth-sized diamond was discovered towards the direction of Aquarius constellation. The information gleaned by researchers to determine the pulsar and dwarf’s distance from Earth has reportedly been crucial to exacting the formula used to determine the time of arrival between pulses and the Earth using the Green Bank Telescope. While this larger than life jewel is what scientists claim to be just one of many in the universe, this discovery still marks an exciting acquisition for modern astronomy.
By Mariah Beckman