Omwamwi was less than expected by scientistsIn the new study obtained data about the first known interstellar object that flew through the Solar system, writes the Chronicle.info with reference to the Telegraph.
Omwamwi was first registered in October 2017 with a telescope Pan-STARRS 1 in Hawaii during the inspection of the near-earth asteroids. Further observations carried out by numerous ground-based telescopes and the space telescope "Hubble", showed that from the surface of the object reflected sunlight. Large brightness variations of the object led to the conclusion that Omwamwi has an elongated shape and is likely no more than 800 meters in length.
Recently in the journal Astronomical Journal a new study according to which some inferences about Omwamwi not quite true.
Space telescope "Spitzer" tracks asteroids and comets using infrared energy, or heat, radiated by them. It can provide more accurate information on the size of the object than the optical observations or reflected sunlight. The fact that Omwamwi was too dim for "Spitzer", puts certain limits relative to the total area of its surface.
Using three different models that provide different assumptions about the composition of the object, "Spitzer" restricted spherical diameter Omwamwi to 400, 140 and 100 meters. Big difference in the results are based on hypotheses about the composition Omwamwi, affects how he can see "Spitzer" at a certain size.
"Omwamwi was full of surprises from the very first day, so we could not wait showing" Spitzer, "says the study's lead author Professor David Trilling of Northern Arizona University. – The fact that Omwamwi too small to "Spitzer" could register it, is actually a valuable result. "
New size limits correspond to the recent research, conducted by astronomer Marco Micheli with ESA. According to them small changes in speed and direction Omwamwi occurred as a result of degassing. In other words, allocated from the surface of the gas acted like a small accelerator.
Omwamwi also proved to be a little less ordinary comets in the Solar system. The conclusion that he has experienced degassing, suggests that it was composed of frozen gases like a comet.
"Our study also suggests that Omwamwi can be 10 times more reflective (have a higher albedo. – Approx. Ed) than comets in the Solar system," says Trilling.
The albedo of the comet may change during its "life". When approaching the Sun, its ice heats up and turns into gas, sweeping away surface dust and dirt, showing more reflects ice.
Omwamwi traveled through interstellar space millions of years away from the stars that could "refresh" the surface. But perhaps it is sufficiently warmed up when approaching the Sun for about five weeks before its opening.
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