Dave's Universe Year of Pluto. Groups Why Join? Astronomy Day. The Complete Star Atlas. Astronomers confirm date by comparing photographs taken 17 years apart to study the famous supernova's expansion speed. This new Subaru image used in the study was released in March By measuring the proper motion of the supernova debris across the plane of the sky over 17 years, this group of astronomers was able to confirm the explosion date.
A team of astronomers has recalculated the explosion date of the famous Crab Nebula supernova and found excellent agreement between their measurements and the classic date of the a. The research was led by Gwen Rudie, a senior physics major at Dartmouth. She and her adviser, Robert Fesen, along with Toru Yamada from Japan's Subaru Observatory in Hawaii, used photographs taken 17 years apart to study the expansion speed of the Crab Nebula, in results released May 29 in Honolulu at the th meeting of the American Astronomical Society.
These astronomers found that the outermost part of the supernova remnant, a very faint "jet" of stellar debris, shows clearly for the first time that the Crab exploded around the middle of the 11th century, in perfect accord with historic records.
The star was so brilliant that it was visible even during the day for nearly three weeks and only faded from view nearly two years later. While the Crab Nebula's location in the sky agreed very well with the reported position of this bright new star, several studies of the expanding cloud of stellar debris unexpectedly indicated that it was expanding much too fast to be associated with a supernova explosion in Instead, these studies pointed later in time, toward an explosion date in the first half of the 12th century.
This dilemma led astronomers to the idea that the remnant's central pulsar — the rapidly spinning and extremely dense neutron star left over from Crab's supernova explosion — emitted such copious amounts of energy that it actually accelerated the expanding cloud of debris, making it move faster with time.
That was the key to our new age determination. Strong aurorae dazzle astronauts on space station. Long trips to space linked to possible brain damage.
First crewed Artemis Moon landing delayed until at least Gift ideas for astronomy lovers and stargazers — holiday gift guide. This "guest star," as the Chinese called it, was so bright that people saw it in the sky during the day for almost a month.
During that time, the star was blazing with the light of about million suns. The star remained visible in the evening sky for more than a year.
In two separate accounts, Chinese astronomers described the star as having pointed rays in all four directions and a reddish-white color. If the blast had occurred 50 light-years from Earth, astronomers believe that all living things could have been destroyed by radiation. In the nine centuries since, astronomers have witnessed only two comparable cataclysms in our Galaxy: the supernova explosions of and By Chinese accounts, the supernova was a tremendous celestial display.
But the Europeans may not have agreed, because astronomers have not found any European records of the event. The American Indians in northern Arizona, however, may have been so inspired by the event that they drew pictures of it. Two pictographs have been found, one in a cave at White Mesa and the other on a wall of Navajo Canyon.
Both show a crescent moon with a large star nearby. Scientists have calculated that on the morning of July 5, , the Moon was located just 2 degrees north of the Crab Nebula's current position. We can use the document 4 positions of some stars visible with the telescope , to locate the center of the nebula.
Looking nearly at the two photographs, we observe some differences caused by the expansion of the nebula. This expansion seems to be more important for the filaments which are far from the center. This is logical because these filaments are developping themselves perpendicular to the direction of our observation.
The filaments which are near the center, are streching themeselves in our direction, they are growing to us and and their developpements seem us, not so large. Calculation of the scales. First, we shall use the document 4. We can find of the photographs the stars which are on this document and so, find the center of the nebula.
Then, we can measure the distance between the stars A and B on each document, 2, 3 and 4 and we know that the angular distance between A and B is second of angle. We are now able to calculate the scale of each photograph in second of angle per millimeter. The choice of the filament for our study. Choice the brillant extremity of 10 filaments which are regularely disposed all along the periphery of the nebula.
Give them the numbers 1 and 1'; 2 and 2', n and n' and so on. Then, we have to measure very carefully the distances xn mm and xn' mm of each extremity to the center of the nebula. The calculations. We shall use the scales to change the measures xn and xn' in angular distances, Xn and Xn', which are in second of angle. Then the differences Xn' - Xn will be divided by the difference, in years, between the dates of the two photographs. We shall obtain with this operation, the velocity of the expansion of the nebula in second of angle per year.
With the hypothesis that this velocity has been the same since the first day, we can calculate the duration of the expansion from the birth of the nebula to the date of the second phtograph. We shall gather the results of all the participants of the workingshop and calculate the main value and the precision of this result. We hope a result about years, according to the idea that the Crab Nebula would be the remaining of the supernova seen in Toggle navigation.
EAAE More The age of the Crab Nebula.
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