By running repeated computer simulations, he has worked out what would happen if a red-dwarf star were to pass through the solar system.
Such a small M-dwarf star has long been ruled out by WISE data, since observers would surely have spotted an object larger than roughly five Jupiter masses.
These new models of failed supernovae demonstrate how both normal brightness and extremely dim supernovae are generated from the same basic picture of a nuclear-burning white dwarf star, he added.
Now, an international team of astronomers has trained the Fermi space-based gamma ray telescope on V407 Cygni, a "binary" system comprising a white dwarf star and a red giant companion, 9, 000 light-years away.
Standard Type Ia supernovae are binary systems in which a white dwarf star draws so much matter from its companion (often a red giant) that it undergoes a kind of energy overload and detonates.
Depending on its initial mass, it might collapse to a compact hot star known as a white dwarf (when the star's mass is less than 1.4 times the mass of our sun) or to a neutron star (for stars 1.4 to about three times the mass of our sun) or to a black hole (for stars more massive than three times the mass of our sun).
The planet orbits its host star, or brown dwarf, with an orbital radius similar to that of Venus.
And when they aimed at Sirius they could see the dim white-dwarf which orbits what is the brightest star in the night sky.
Their goal was to measure distant Type 1a supernovae - the brilliant ends of a particular kind of dense star known as a white dwarf.
The pulsar and white dwarf pair emit gravitational waves and the binary star system gradually loses energy.
One, known as a white dwarf, is the cooling remnant of a much lighter star.
Those white dwarf stars that find themselves near a "companion" star can draw material from their neighbour, building up to a critical mass and eventually sparking nuclear fusion again in a nova.
It becomes gravitationally perturbed, with any big planets still orbiting the dead star then nudging smaller rocks in all directions - many of them towards the dwarf.
The white dwarf is thought to have later blown up in a supernova after siphoning matter, or fuel, from a nearby star.
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