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  • feedwordpress 10:01:22 on 2018/11/06 Permalink
    Tags: , , , , interstellar space, Oumuamua, , solar sail, , supernova, Tycho Brahe, , Wolfgang Schüler   

    “I’m sure the universe is full of intelligent life. It’s just been too intelligent to come here.”*… 

     

    couldoumuamu

    Artist’s impression of the first interstellar asteroid/comet, “Oumuamua”

     

    Or not…

    On October 19th, 2017, the Panoramic Survey Telescope and Rapid Response System-1 (Pan-STARRS-1) in Hawaii announced the first-ever detection of an interstellar asteroid, named 1I/2017 U1 (aka, ‘Oumuamua). In the months that followed, multiple follow-up observations were conducted that allowed astronomers to get a better idea of its size and shape, while also revealing that it had the characteristics of both a comet and an asteroid.

    Interestingly enough, there has also been some speculation that based on its shape, ‘Oumuamua might actually be an interstellar spacecraft (Breakthrough Listen even monitored it for signs of radio signals!). A new study by a pair of astronomers from the Harvard Smithsonian Center for Astrophysics (CfA) has taken it a step further, suggesting that ‘Oumuamua may actually be a light sail of extra-terrestrial origin…

    As for what an extra-terrestrial light sail would be doing in our solar system, [Harvard astronomers Shmuel Bialy and Prof. Abraham Loeb] offer some possible explanations for that. First, they suggest that the probe may actually be a defunct sail floating under the influence of gravity and stellar radiation, similar to debris from ship wrecks floating in the ocean. This would help explain why Breakthrough Listen found no evidence of radio transmissions.

    Loeb further illustrated this idea in a recent article he penned for Scientific American, where he suggested that ‘Oumuamua could be the first known case of an artificial relic which floated into our solar system from . What’s more, he notes that lightsails with similar dimensions have been designed and constructed by humans, including the Japanese-designed IKAROS project and the Starshot Initiative with which he is involved.

    “This opportunity establishes a potential foundation for a new frontier of space archaeology, namely the study of relics from past civilizations in space,” Loeb wrote. “Finding evidence for space junk of artificial origin would provide an affirmative answer to the age-old question “Are we alone?”. This would have a dramatic impact on our culture and add a new cosmic perspective to the significance of human activity.”

    On the other hand, as Loeb told Universe Today, ‘Oumuamua could be an active piece of alien technology that came to explore our solar system, the same way we hope to explore Alpha Centauri using Starshot and similar technologies”…

    More provocative detail at “Could ‘Oumuamua be an extraterrestrial solar sail?

    * Arthur C. Clarke

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    As we ask if we’re alone, we might recall that it was on this date in 1572 that Wolfgang Schüler first noted a supernova in the W-shaped constellation of Cassiopeia.  It was subsequently seen by other observers, including Tycho Brahe, who included an account of the sighting in his De nova stellaConsequently, the supernova– one of eight visible to the naked eye in historical records– is known as “Tycho’s Supernova.”

    Tycho_Cas_SN1572

    Star map of the constellation Cassiopeia showing the position (labelled I) of the supernova of 1572; from Tycho Brahe’s De nova stella

    source

     

     

     
  • feedwordpress 08:01:48 on 2017/04/30 Permalink
    Tags: 1006, , , event horizon, Event Horizon Telescope, , , supernova, ,   

    “The history of astronomy is a history of receding horizons”*… 

     

    The closest astronomers have come to directly “seeing” a black hole happened last year, when the LIGO observatory detected the spacetime-warping gravitational waves radiating from a pair of black holes that collided some 1.3 billion years ago.

    That’s cool. But for astronomers, it’s not enough. What’s eluded them is a view of the event horizon, the boundary of the black hole from which, when crossed, there is no return. After the event horizon, gravity is so intense that not even light can escape.

    We’ve never seen a direct image of a black hole. But if an audacious experiment called the Event Horizon Telescope is successful, we’ll see one for the first time…

    Find out how at “Astronomers just turned on a planet-size telescope to take a picture of a black hole.”

    * Edwin Hubble

    ###

    As we look into it, we might recall that it was on this date in 1006 CE that observers across China, Japan, Iraq, Egypt, and Europe recorded their observation of a supernova (now known as SN 1006).  Likely the brightest observed stellar event in recorded history, it reached an estimated −7.5 visual magnitude (more than sixteen times the brightness of Venus).  Many experts believe that it was also recorded in the Native American petroglyphs in White Tank Mountain Regional Park, Arizona, making them the first North American record of a supernova sighting.

    SN 1006 supernova remnant

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