back to article Is it a bird? Is it a plane? No, it's a charred white dwarf star blasted across our galaxy by an ancient semi-supernova

A rogue white dwarf star hurtling through the Milky Way may have freed itself from a binary system after it partially exploded as a supernova more than 40 million years ago. The star, snappily code-named SDSS J1240+6710, was discovered in 2015, and has odd properties scientists couldn’t initially explain. Unlike typical white …

  1. KittenHuffer Silver badge

    I reckon ...

    ... that one of Johnny Fartpants ancestors happened to be visiting the system, and had a 'little' accident!

  2. MiguelC Silver badge

    900,000 KPH (559,234 MPH)

    I'm pretty sure the original measurement wasn't that precise...

    1. Annihilator

      Re: 900,000 KPH (559,234 MPH)

      I often wonder.... relative to what?

      1. Anonymous Coward

        Re: 900,000 KPH (559,234 MPH)

        Relative to the rest-frame of the galaxy in this case, I think. And in fact the numbers are even more frightening. If I've read the paper properly, it's moving about 250km/s against the rotation of the galaxy which is about 239km/s where it is, so it's motion relative to the stars it is near is something like 500km/s, or 1,800,000km/h.

      2. Cuddles

        Re: 900,000 KPH (559,234 MPH)

        Peculiar motion relative to the galactic rest frame. It's essentially one of the two standard frames for observations of things within the galaxy (the other being the Solar System centre of mass), found by taking the average motion of eveything in the galaxy.

        Particularly notable, although for some reason not mentioned in the article, is that this star isn't just moving very fast, it's also going backwards.

    2. KarMann Silver badge

      Re: 900,000 KPH (559,234 MPH)

      'Significant figures, motherf**ker, do you speak them?'

  3. Doctor Syntax Silver badge

    "Prof Gaensicke believes the star is proof that there may be different types of supernova that astronomers haven’t yet classified."

    Waiting for one of them to be classified as a bossanova.

    1. Annihilator

      Would be great if those objects were the the source of dark matter. Then scientists would be able to blame it on the bossanova.

  4. Graham Cunningham

    Alternative ending:

    "will keep traveling through the galaxy alone, until it eventually uses up the rest of its fuel and dies."


    "will keep traveling through the galaxy alone, until it hits something."

    1. Tom 7

      Re: Alternative ending:

      Or until it uses up all its fuel and gets cold and still carries on travelling probably out of the galaxy - which is mainly space but less spacey than space.

      1. oldfartuk

        Re: Alternative ending:

        Eventually arriving FINALLY at the Chemists.

  5. yas1

    Surely it's Dave's cueball...

    Still rolling through space after the White Hole shot?

    1. Jimmy2Cows Silver badge

      Re: Surely it's Dave's cueball...

      Wasn't that playing pool with planets?

  6. John Brown (no body) Silver badge

    Boskonians or Galactic Patrol?

    Is someone testing out a new weapon?

    1. Anonymous Coward

      Re: Boskonians or Galactic Patrol?

      Yes, sorry. Those responsible have been reprimanded. This one wasn't actually armed though: the live versions will be firing orbiting pairs of white dwarfs, very close to the point at which the larger one accretes enough from the smaller to become a type 1a supernova, timed to occur within the enemy's defensive screens. Fuzing has proved difficult however.

      1. You aint sin me, roit

        Re: Boskonians or Galactic Patrol?

        The white dwarf is just the recoil...

        There's a magnetar flying out in the opposite direction, coupling (geddit) disruptive magnetic fields with a kinetic threat. And a dose of hard radiation.

        Given that the white dwarf is travelling through the milky way it would appear that someone is repelling intergalactic invaders!

  7. Blackjack Silver badge

    So if this thing crashes into a planet

    It will be a literal falling star?

  8. JCitizen
    IT Angle

    Stuff to think about..

    I wonder if this formerly binary system was close to merging, and the event happened before this merger was successful - also the two objects could have been circling each other at astounding speeds as well - but because one of them went NOVA just before the merger, somehow the angular velocity was preserved and imparted a nearly equal and opposite reaction, instead of simply merging and becoming another form of star, or even a black hole. I've never read that a binary system merging like that ever ended up changing from original direction before, so I'm assuming as a novice astrophysics fan, that something completely different had to happen like that. It would seem that much of the matter from both stars would have coalesced however, and just an expanding blast wave with left over gases was left at the event site. Also, I wonder if anyone is gathering data on what are the known universe's fastest objects (relatively speaking of course)

    With that incredible speed, it would sure be fun, to watch at a safe distance and see this rogue dwarf slam into another mass of any type in the galactic plane!! Just the thought of that thing moving so fast against the grain of the galaxy would seem like at least doubling the chances of a collision - but the disappointing reality, is that entire galaxies probably pass right through each other with barely even one of such meetings.

  9. Spherical Cow Silver badge

    The object was discovered after astronomers detected the following unusual signal:


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