+ Reply to Thread
Results 1 to 4 of 4

Thread: Space's 10 Most Mysterious Stars

  1. Link to Post #1
    On Sabbatical
    Join Date
    10th July 2013
    Location
    Project Avalon
    Posts
    3,649
    Thanks
    19,216
    Thanked 16,228 times in 3,216 posts

    Default Space's 10 Most Mysterious Stars


    Space's 10 Most Mysterious Stars

    1. HD 140283, informally nicknamed Methuselah star, lies 190.1 light-years away and is one of the closest Population II stars to us. The star could be as old as 14.5 billion years (plus or minus 0.8 billion years), which at first glance would make it older than the universe's calculated age of about 13.8 billion years.


    -------------------------------------------------------------------------------------------------

    2. What sets SGR 0418+5729 apart from other magnetars is that careful monitoring over a span of 490 days has revealed no detectable decrease in its rotation rate. Researchers were able to make an accurate estimate of the strength of the external magnetic field. “The spectral data [...] allowed us to finally make the first detailed measurements of the magnetic field of a magnetar, confirming it as one of the largest values ever measured in the Universe” (Norbert Schartel, ESA’s XMM-Newton Project Scientist).


    -------------------------------------------------------------------------------------------------

    3. In January 2002, V838 Monocerotis suddenly became 600,000 times more luminous than our Sun, temporarily making it the brightest star in our Milky Way galaxy. The reason for the outburst is still uncertain, but several conjectures have been put forward, including an eruption related to stellar death processes and a merger of a binary star or planets. By 2009 its temperature had increased to 3,270 K and its luminosity was 15,000 times solar, but its radius had decreased to 380 times that of the Sun although the ejecta continues to expand.


    -------------------------------------------------------------------------------------------------

    4. LRLL 54361 is thought to be a binary protostar producing strobe-like flashes, located in the constellation Perseus in the star-forming region IC 348 and 950 light-years away. The object emits a burst of light every 25.34 days. The flashes may be the result of large amounts of matter falling into the growing protostars.

    Last edited by Atlas; 15th March 2015 at 19:58.

  2. The Following 15 Users Say Thank You to Atlas For This Post:

    Agape (15th March 2015), Alekahn2 (15th March 2015), Bob (16th March 2015), Cidersomerset (15th March 2015), DeDukshyn (15th March 2015), ghostrider (15th March 2015), Hod8 (15th March 2015), Lifebringer (15th March 2015), mab777 (15th March 2015), Octavusprime (16th March 2015), ponda (15th March 2015), Richard S. (16th March 2015), seko (15th March 2015), Stephanie (15th March 2015), Ulyse30 (15th March 2015)

  3. Link to Post #2
    On Sabbatical
    Join Date
    10th July 2013
    Location
    Project Avalon
    Posts
    3,649
    Thanks
    19,216
    Thanked 16,228 times in 3,216 posts

    Default Re: Space's 10 Most Mysterious Stars

    -------------------------------------------------------------------------------------------------

    5. V886 Centauri is the most massive pulsating white dwarf currently known. Located 50 light-years away from Earth, the star is a chunk of crystallized carbon that weighs 5 million trillion trillion pounds. That would equal a diamond of 10 billion trillion trillion carats.


    -------------------------------------------------------------------------------------------------

    6. SAO 206462 attracted attention because it has a circumstellar disk--that is, a broad disk of dust and gas surrounding the star. Theoretical models show that a single embedded planet may produce a spiral arm on each side of a disk. The structures around SAO 206462, however, do not form a matched pair, suggesting the presence of two unseen worlds, one for each arm.


    -------------------------------------------------------------------------------------------------

    7. Cygnus X-3 is a microquasar and a very bright radio source that undergoes massive flares from time to time. These flares are of unknown origin, but they are exceedingly violent events. Naval Research Laboratory observations in October 1982 using the Very Large Array detected the shock wave from a flare; it was expanding at roughly one-third the speed of light.


    -------------------------------------------------------------------------------------------------

    8. Though Jabbah (Nu Scorpii) appears to be a single star, it is actually a whole system of stars (possibly as many as seven), each of which is many times more massive, larger, hotter and more luminous than the sun. The Jabbah system is located about 440 light-years away from us.


    -------------------------------------------------------------------------------------------------

    9. 90377 Sedna is one of the most distant known objects in the Solar System other than long-period comets. Sedna's exceptionally long and elongated orbit, taking approximately 11,400 years to complete, and distant point of closest approach to the Sun, at 76 AU, have led to much speculation about its origin.


    -------------------------------------------------------------------------------------------------

    10. AE Aquarii is a cataclysmic variable binary star consisting of an ordinary star in a close orbit around a magnetic white dwarf. The white dwarf has the shortest known spin period of any white dwarf, completing a full revolution every 33.08 seconds. Mass is being lost from the secondary star, most of which is being flung out of the system by the rapidly spinning magnetic primary. The X-ray luminosity is likely being caused by the accretion of mass onto the white dwarf, which is occurring at an estimated rate of about 7.3×10^10 kg per second.


  4. The Following 11 Users Say Thank You to Atlas For This Post:

    Agape (15th March 2015), Alekahn2 (15th March 2015), Bob (16th March 2015), Cidersomerset (15th March 2015), DeDukshyn (15th March 2015), Hod8 (15th March 2015), mab777 (15th March 2015), Octavusprime (16th March 2015), ponda (15th March 2015), seko (15th March 2015), Stephanie (15th March 2015)

  5. Link to Post #3
    UK Avalon Member Cidersomerset's Avatar
    Join Date
    16th May 2011
    Location
    Bridgwater somerset UK
    Age
    63
    Posts
    22,333
    Thanks
    33,460
    Thanked 79,637 times in 18,693 posts

    Default Re: Space's 10 Most Mysterious Stars

    Thanks buares a beautiful post......I have been following all these exo planet and
    other cosmic objects caught on hubble over the last decade or so...

    I saw an interesting article yesterday and was wondering where to put so I'll
    post it here if you don't mind......

    ====================================================



    12 March 2015 Last updated at 17:49

    Hubble finds 'best evidence' for Ganymede subsurface ocean By Jonathan Amos

    BBC Science Correspondent


    An artist's impression showing Jupiter, and the moon Ganymede with its auroral lights


    There is further, compelling evidence that Ganymede - the largest moon in the
    Solar System - has an ocean of water beneath its icy crust.The new data comes
    from the Hubble Space Telescope, which has been studying how auroral lights
    dance around the satellite of Jupiter.The presence of a sub-surface ocean would
    heighten interest in Ganymede as a potentially habitable world.

    Europe's robotic Juice probe is being sent to orbit the moon in the 2030s.

    Nasa's Galileo mission returned information in the early 2000s that suggested the
    5,300km-wide moon had a hidden sea. The new insights from Hubble deepen that
    impression.

    Damping effect

    Ganymede's great distinction among moons - apart from its size - is that it has its
    own magnetic field. Hubble has managed to track that field's behaviour by watching
    how it draws in and excites space particles, generating a glow of ultraviolet light
    around the satellite's north and south poles. But this intrinsic magnetic field also
    Interweaves with Jupiter's, and the aurora "rock" back and forth as a result of the
    interplay.It is by modelling the expected rocking against what is observed by
    Hubble that scientists can infer something about the internal structure of the moon.
    And they now say a salty ocean at depth is the best explanation for what they see.
    That is because Jupiter's field induces a secondary field in the salt water, and this
    tries to counterbalance the big planet's influence.The end result is that the aurora
    rock only by two degrees over time when without the presence of the ocean, they
    should be rocking by six degrees.

    Magnetic interplay

    Continue reading the main story
    The JUpiter ICy moon Explorer
    Juice concept



    Would launch on Ariane rocket in 2022
    Journey to Jupiter system takes eight years
    Will study gas giant as well as moons
    Fly-bys planned for moons Callisto and Europa
    First mission to orbit an icy moon - Ganymede
    Would end mission by crashing into surface

    "The ocean cannot be deeper than 330km; anything deeper would not explain the
    data," said lead scientist Joachim Saur of the University of Cologne in Germany.

    "The data are consistent with an ocean of a 100km thickness with a certain salt
    content of about 5g per one litre of water. But it could equally well be an ocean of
    only 10km but with 10 times more salt."

    The idea that a sub-surface ocean exists on Ganymede is exciting because
    wherever you have liquid water, you have one of the main ingredients for life.
    You need much more, of course - not least a source of energy and some complex
    carbon chemistry. But understanding the ocean will be one of the primary
    objectives of the European Space Agency's billion-pound Juice robot when it arrives
    at Ganymede in 2030.

    The orbiter will have a very sensitive magnetometer instrument to study
    Ganymede's magnetic field in more detail, as well as a radar instrument to look
    beneath the icy crust. But other types of observations, like gravity measurements,
    should also elicit additional insights.

    'Soggy' Solar System
    Heidi Hammel, from the Association of Universities for Research in Astronomy,
    Washington DC, said the Hubble information represented the "best evidence yet"
    for Ganymede's hidden ocean. Although the Galileo orbiter had strongly suggested
    the water volume was present, it was possible still to interpret its magnetometer
    information in different ways, she explained.

    "There was some ambiguity, which is why the word 'putative' was still used [in
    relation to the ocean]. But this result takes us out of the realm of ambiguity," she
    told reporters.

    Ganymede is just one of a large list of objects in the Solar System now thought to
    hide an ocean deep below the surface. These include the dwarf planets Pluto and
    Ceres; other Jupiter moons - Europa and Calisto; Saturn's moons Enceladus, Titan
    and Mimas; and possibly Neptune's moon, Triton.

    "The Solar System is now looking like a pretty soggy place," joked Jim Green, the
    US space agency's director of planetary science.Interior of Ganymede With a
    diameter of 5,268km, Ganymede is the largest moon in the Solar System




    One of four big Jovian moons seen by Galileo
    Takes roughly seven days to orbit Jupiter
    Only moon known to possess a magnetosphere
    Darker regions are more ancient than lighter ones
    Previously visited by Voyager and Galileo probes
    Destination for Esa's Juice probe in 2030s
    Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos

    http://www.bbc.co.uk/news/science-environment-31855395
    Last edited by Cidersomerset; 15th March 2015 at 21:35.

  6. The Following 5 Users Say Thank You to Cidersomerset For This Post:

    Atlas (15th March 2015), Bob (16th March 2015), Hod8 (15th March 2015), Octavusprime (16th March 2015), Ulyse30 (15th March 2015)

  7. Link to Post #4
    Egypt Avalon Member
    Join Date
    11th March 2015
    Posts
    23
    Thanks
    17
    Thanked 78 times in 17 posts

    Default Re: Space's 10 Most Mysterious Stars

    Quote Posted by buares (here)

    1. HD 140283, informally nicknamed Methuselah star, lies 190.1 light-years away and is one of the closest Population II stars to us. The star could be as old as 14.5 billion years (plus or minus 0.8 billion years), which at first glance would make it older than the universe's calculated age of about 13.8 billion years.
    I have another theory, And it goes like this...
    There are parallel universes. And when two universe collide the big bang happens, Usually this destructive event regenerates 99.999 or better percentage of both universe but due to the great explosion and sudden cool down some debris remains in the universe which is older then the birth of new universe. We may be witnessing some of this as our knowledge horizons expand over time and space.

  8. The Following 2 Users Say Thank You to Hod8 For This Post:

    Atlas (15th March 2015), Cidersomerset (15th March 2015)

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts