In 2029, sky watchers may spot at least one man-made “star” in the sky.
Earlier this week NASA announced plans to place a small satellite in Earth orbit just over 22,000 miles (35,400 kilometers) above our planet’s surface—far enough for the satellite to mimic a real star for telescopes. Earth. Scientists say the satellite, named Landolt, wouldn’t be bright enough to be seen with the naked eye, but if you have personal binoculars at home, you might catch a glimpse of the shoebox-sized object hovering over the United States. in a stationary position.
The mission’s primary goal is to help calibrate telescopes on Earth and create new, more accurate catalogs of the brightness of real stars.
Once in orbit, satellite will beam eight onboard lasers to ground-based telescopes that would observe the “artificial star” in the same frame as their science targets. By measuring how much light from the lasers — which would have a predetermined brightness — is absorbed by our planet’s atmosphere, astronomers can compare it to about 60 real stars, cataloging the star’s brightness as seen from Earth more accurately than conventional methods. achieve.
“Lasers in space is a pretty great selling point, as is getting to work on the mission,” mission team member Jamie Tayarassistant professor of astronomy at the University of Florida, said va declaration. “But scientifically, what we’re trying to do here is really fundamental.”
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Better star luminosity catalogs will improve the precision with which various properties of stars, such as their brightness, size and age, are measured. This precision, in turn, may allow scientists to fine-tune other measurements that also rely on star brightness and distance. For example, stellar dynamics like this help us measure the age of space and how quickly it spread time. Astronomers can also infer more precisely how much energy is emitted from stars, which could help find orbits. exoplanets with potentially life-friendly conditions.
“There are so many big questions astronomy: How did we get here? Are there other planets like ours? Are there aliens?” Tayar asked. “But these are really hard questions, so to answer them, the measurements have to be really good and they have to be right.
Normally, when measuring the universe, astronomers rely on stars referred to as “standard candles” which can be compared to light bulbs of known wattage. The luminosity and distance factors for these stars are well recorded and are therefore used as tools for measuring the distances between other stars or galaxies and Earth. However, these measurements were made in the 1990s and “became a major source of measurement error luminosity for most stars,” according to a Press Release The University of Montreal in Canada, which is participating in the mission.
“When you look at a star through a telescope, nobody today can tell you the speed of the photons or the brightness coming out of it with the level of accuracy you want,” he said. Petr Plavchan from George Mason University, who is the mission’s principal investigator. “Now we will know exactly how many photons per second come out of this source with an accuracy of 0.25 percent.”
Data from the $19.5 million Landolt mission will reduce uncertainties in star brightness measurements from 10 percent to one percent, astronomers say. “That’s the difference when it spreads into the properties of exoplanets and, believe it or not, some of the parameters used to determine the structure universe” said Angelle Tanner of Mississippi State University, who is leading the mission’s science and managing the $300,000 sub-grant. declaration.
The mission is named in honor of the late American astronomer Arlo Landolt, who is best known for his photometric standard star lists, which are widely used as calibration standards in the study of new objects in the sky. Mission control will be based out of the George Mason University campus in Fairfax County, Virginia, in collaboration with scientists from 12 institutions. The payload itself will be built by the US Department of Commerce’s National Institute of Standards and Technology, which is based in Maryland.