John Carlos Baez on Nostr: As big stars age, they more intense and scary. Among the worst are the 'black ...
As big stars age, they more intense and scary. Among the worst are the 'black widows'.
When a star between 10 and 25 times heavier than our Sun runs out of fuel, its core collapses and then it explodes in a supernova, leaving behind a ball of neutrons 10 kilometers across with mass slightly bigger than our Sun. If this is spinning fast - and it often will be! - deadly beams of radiation will shoot from near its poles. This is called a pulsar.
Now imagine that this star had another star orbiting it. This is not rare: most stars come in pairs!
If the pulsar's beam happens to hit its companion star, it's like blasting a firehose at a big pile of sand. The companion doesn't get instantly destroyed, but its gas gets ripped off and it gradually shrinks away.
If the companion is less than 1/10 the mass of the Sun, we call the pulsar a 'black widow'. If it's bigger, we call the pulsar a 'redback' or 'huntsman' - two other kinds of poisonous spider.
This video shows PSR J1311-3430, a black widow discovered in 2012. Astronomers were carefully looking at a pulsar and found it has a small companion that changes color from intense blue to dull red every hour and a half.
It turns out the pulsar's beam is heating a red dwarf, making it blue-hot! The side of this star facing the pulsar is heated to 12,000 °C, more than twice as hot as the Sun’s surface. The other side stays red, glowing at a temperature of 2,700 °C — half the Sun’s surface temperature.
I shudder to think what would happen to a planet anywhere near a pulsar.
More: https://en.wikipedia.org/wiki/PSR_J1311%E2%80%933430
https://www.youtube.com/watch?v=kgI3w4SOAik
When a star between 10 and 25 times heavier than our Sun runs out of fuel, its core collapses and then it explodes in a supernova, leaving behind a ball of neutrons 10 kilometers across with mass slightly bigger than our Sun. If this is spinning fast - and it often will be! - deadly beams of radiation will shoot from near its poles. This is called a pulsar.
Now imagine that this star had another star orbiting it. This is not rare: most stars come in pairs!
If the pulsar's beam happens to hit its companion star, it's like blasting a firehose at a big pile of sand. The companion doesn't get instantly destroyed, but its gas gets ripped off and it gradually shrinks away.
If the companion is less than 1/10 the mass of the Sun, we call the pulsar a 'black widow'. If it's bigger, we call the pulsar a 'redback' or 'huntsman' - two other kinds of poisonous spider.
This video shows PSR J1311-3430, a black widow discovered in 2012. Astronomers were carefully looking at a pulsar and found it has a small companion that changes color from intense blue to dull red every hour and a half.
It turns out the pulsar's beam is heating a red dwarf, making it blue-hot! The side of this star facing the pulsar is heated to 12,000 °C, more than twice as hot as the Sun’s surface. The other side stays red, glowing at a temperature of 2,700 °C — half the Sun’s surface temperature.
I shudder to think what would happen to a planet anywhere near a pulsar.
More: https://en.wikipedia.org/wiki/PSR_J1311%E2%80%933430
https://www.youtube.com/watch?v=kgI3w4SOAik