Omwamwi was less than expected by scientistsThe new study obtained data about the first known interstellar object that flew through the solar system, writes Chronicle.info with reference to the Telegraph.
Omwamwi was recorded for the first time in October 2017 with a Pan-STARRS 1 telescope in Hawaii during the review of asteroids close to the earth. Additional observations made by ground telescopes and the Hubble Space Telescope have shown that they reflect the sunlight from the surface of the object. Large variations in the subject's brightness have led to the conclusion that Omwamwi has an elongated shape and is probably no more than 800 meters in length.
Recently, in the journal Astronomical Journal, a new study suggests that some inferences about Omwamwi are not really true.
Space Spitzer tracks asteroids and comets through infrared energy or heat radiated by them. It can provide more accurate information about the size of the object than the optical observations or reflected light of the sun. The fact that Omwamwi was too sweet for "Spitzer" sets certain limits in terms of the total area of its surface.
Using three different models that offer different assumptions about the composition of the object, Spitzer limited the Omwamwi spherical diameter to 400, 140 and 100 meters. The big difference in results is based on hypotheses about Omwamwi's composition that influence how they see "Spitzer" at a certain size.
"Omwamwi was full of surprises from the first day, so we could not wait to show" Spitzer, "says lead author David Trilling of the University of Northern Arizona." The fact that Omwamwi is too small for Spitzer, can record it, is actually a valuable result. "
New dimensional limits correspond to the recent research carried out by astronomer Marco Micheli from ESA. According to them, small changes in the speed and direction of Omwamwi occurred as a result of degassing. In other words, allotted from the surface of the gas acted as a small accelerator.
Omwamwi turned out to be somewhat less than the normal comets in the solar system. The conclusion that he experienced degassing, implying that it consisted of frozen gas as a comet.
"Our study also suggests that Omwamwi can be 10 times more reflective (with a higher albedo than Approx. Ed.) Than with the solar system comets," says Trilling.
The albedo of the comet may change during "life". When approaching the Sun, the ice gets warm and turns into gas, shaking the dust and dirt on the surface and finding more reflective ice.
Omwamwi traveled through interstellar space millions of years away from stars that could "refresh" the surface. But perhaps it is warm enough when approaching the Sun for about five weeks before it opens.