Thursday, July 30, 2020
Andrew Fraknoi: Exploring the Universe: Hot Blob Signals Presence of Long-Awaited Star Corpse
Andrew Fraknoi: Exploring the Universe: Hot Blob Signals Presence of Long-Awaited Star Corpse: Astronomers have just announced the first indication that a star seen to explode in 1987 has left behind a “neutron star” – a kind of weird ...
Hot Blob Signals Presence of Long-Awaited Star Corpse
Astronomers
have just announced the first indication that a star seen to explode in 1987
has left behind a “neutron star” – a kind of weird star corpse that is more compressed
than any other structure in the universe.
It’s a discovery that has long been hoped for by astronomers to confirm
that our ideas about the deaths of massive stars are correct.
Smaller
stars, like our Sun, die a relative peaceful death, where they simply collapse
under their own weight until they become kind of solid. But the bigger stars become unstable and blow
up at the end of their lives, in an explosion astronomers call a supernova. Most such explosions leave behind a core so
compressed that, in it, atoms as we know them cease to exist. Instead, electrons are squeezed into protons
to make neutrons, essentially removing all empty space within each atom. The
result is a tight ball made mostly of pure neutrons.
To
make something this dense on Earth, we would have to take all the people in the
world and squeeze them into one raindrop!
An entire star collapses to be about the size of a small U.S.
suburb. How could we find such a “squozen”
star corpse? It turns out these neutron
stars are very hot after they form and can heat any left-over gas and dust
around them.
The
most recent nearby supernova explosion that astronomers know of was seen in
February 1987 in a satellite galaxy that orbits our Milky Way. It is given the very unimaginative name Supernova 1987A, being the first one
seen in 1987. Searching the central
regions of the remnant of this supernova, astronomers, using the big array of
radio telescopes called ALMA, have recently found a super-hot blob of material
right where the neutron star was expected to be. All the characteristics of the blob indicate
that is a heated cloud of dust and gas hiding a hot neutron star within.
It
will be decades before the material around the neutron star is cleared out and
we can get a glimpse of the star corpse itself.
But for now, the detailed properties of the blob tell us that it is most
likely hiding just the kind of neutron star astronomers were hoping to see.
(In our radio image, you see a wide ring of
material around the dead star, set to glow by the particles of the explosion
that reach it. The inset shows the central region, with the hot blob glowing
bright in radio waves.)
Wednesday, May 27, 2020
Andrew Fraknoi: Exploring the Universe: SETI Pioneer Frank Drake Celebrates His 90th Birth...
Andrew Fraknoi: Exploring the Universe: SETI Pioneer Frank Drake Celebrates His 90th Birth...: This week, Dr. Frank Drake, the pioneer in the scientific search for intelligent life elsewhere in the cosmos and one of my favorite a...
SETI Pioneer Frank Drake Celebrates His 90th Birthday
This week, Dr. Frank Drake, the pioneer in the scientific search for intelligent life elsewhere in the cosmos and one of my favorite astronomers, turns 90. He has been a really important mentor in my life, with good advice at several crucial career points, and I want to wish him all the best on this occasion.
He is perhaps best known for the ”Drake Equation,” a formula for making estimates of the number of technological civilizations in the Galaxy that are capable of communicating with us. To read an article in which he wrote up “The Origin of the Drake Equation” (for a column I was editing at the Astronomical Society of the Pacific), go to: http://bit.ly/drakearticle
For my 2012 interview with Drake, where he reflects on his work over the years, see: https://www.youtube.com/watch?v=HPQz-kdaxNo&t=536s The accompanying picture shows us on that occasion, at the SETICon convention organized by the SETI Institute, where he and I have been on the Board of Trustees.
With all the reasons to despair of intelligent life here on Earth, I hope we can soon realize Drake's dream of finding it among the stars. A number of projects are carrying on the search he began, and a success would be a great present for his next birthday.
He is perhaps best known for the ”Drake Equation,” a formula for making estimates of the number of technological civilizations in the Galaxy that are capable of communicating with us. To read an article in which he wrote up “The Origin of the Drake Equation” (for a column I was editing at the Astronomical Society of the Pacific), go to: http://bit.ly/drakearticle
For my 2012 interview with Drake, where he reflects on his work over the years, see: https://www.youtube.com/watch?v=HPQz-kdaxNo&t=536s The accompanying picture shows us on that occasion, at the SETICon convention organized by the SETI Institute, where he and I have been on the Board of Trustees.
With all the reasons to despair of intelligent life here on Earth, I hope we can soon realize Drake's dream of finding it among the stars. A number of projects are carrying on the search he began, and a success would be a great present for his next birthday.
Friday, May 8, 2020
Andrew Fraknoi: Exploring the Universe: Radio Interview (with Discussion of the New Black ...
Andrew Fraknoi: Exploring the Universe: Radio Interview (with Discussion of the New Black ...: Today, I was interviewed on the Pat Thurston Show on KGO Radio for an hour, with a good discussion of the recent discovery of the close...
Radio Interview (with Discussion of the New Black Hole Discovery)
You can listen to the podcast of the show https://omny.fm/shows/the-pat-thurston-show/may-8-2020-andrew-fraknoi
Please stay safe and distanced (just as the stars are)!
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