- Dec 22, 2014
- Reaction score
- Wessex and Mercia
Betelgeuse hasn't quite run out of geuse just yet. ...
Ongoing data analysis indicated we needed to revise our last estimates of Betelgeuse's distance, size, and probable time left before it goes supernova.This astronomer posts regular updates about Betelgeuse. The star is slightly brighter than it was, and may be returning to normal. But this chap says it has remained constantly bright when viewed in the infra-red. That probably means this recent 'fainting' is due to dust. ...
FULL STORY:Betelgeuse Is Neither as Far Nor as Large as We Thought, And It's a Total Bummer
In the wake of recent fluctuations in Betelgeuse's brightness, astronomers have rigorously examined the star's vital statistics, and come up with a bit of a surprise.
According to the team led by researchers at Australian National University (ANU), the results change a few important things about our favourite red giant.
"The actual physical size of Betelgeuse has been a bit of a mystery – earlier studies suggested it could be bigger than the orbit of Jupiter," says astronomer László Molnár from the Konkoly Observatory in Hungary.
"Our results say Betelgeuse only extends out to two thirds of that, with a radius 750 times the radius of the Sun." ...
Betelgeuse has always been somewhat difficult to map with much accuracy. ...
In 1920, interference patterns among its light waves were used to come up with an angular diameter – the width of Betelgeuse's starlight as it hangs in our sky – of close to 47 milliarcseconds.
Based on an assumed distance of around 180 light years, the red star was initially thought to have a diameter equivalent to around two and a half times the distance between Earth and the Sun.
Since then there have been many more attempts to drag a metaphorical measuring tape around Betelgeuse's butt. ...
Revisions of its location in the past few years pushed it further back to a distance of 724 light years away, where those 47 milliarcseconds represented something more like 1,300 times the diameter of the Sun; a diameter that would see Betelgeuse swallow up planets roughly in Jupiter's orbit. ...
Using information collected with the space-based Solar Mass Ejection Imager prior to Betelgeuse's recent drop in luminosity, the research team developed models of the star's activity to come up with a better sense of just how close to retirement it really was.
"It's burning helium in its core at the moment, which means it's nowhere near exploding" ...
"We could be looking at around 100,000 years before an explosion happens."
The results also allowed the researchers to deduce the giant's radius, shaving a third off its previous girth. Based on this new figure, Betelgeuse can't be more than 700 light years away, either.
"Our results show it's a mere 530 light years from us – 25 per cent closer than previous thought," says Molnár. ...
Now that we know Betelgeuse is even closer to us than we thought, it's sure to be one heck of a display when it does eventually collapse. If you're at all concerned about the new seating arrangements, at 530 light years we still won't be close enough to feel the heat of its radiation either. ...
Update.Bennu is literally exploding with news.
For the last year, NASA’s OSIRIS-REx spacecraft has been circling a large asteroid named Bennu that regularly passes uncomfortably
close to Earth. The spacecraft has been painstakingly mapping the asteroid’s rocky surface using a suite of cameras and other instruments that will help it determine where to land next year. Once NASA selects a final landing site, OSIRIS-REx will kiss Bennu just long enough to scoop up a sample to bring back to Earth in 2023.
Many scientists expect the Bennu sample to revolutionize our understanding of asteroids, especially those that are near Earth and pose the greatest threat to life as we know it. But as detailed in a paper published today in Science, NASA has already started making surprising discoveries around this alien world. Earlier this year, the OSIRIS-REx team witnessed particles exploding from the asteroid’s surface—and it’s not sure why.
“No one has ever seen an active asteroid up close like this,” says Carl Hergenrother, an astronomer at the University of Arizona and the scientist who proposed Bennu as the target for OSIRIS-REx. “It wasn’t that long ago that the conventional wisdom was that asteroids are these dead bodies that didn’t change very much.”
In January, the navigation cameras on OSIRIS-REx captured three ejection events that each spewed about 100 centimeter-sized asteroid particles into space. The spacecraft also detected a significant number of particles already orbiting Bennu like a cloud of gnats. Their diverse orbits suggest that particle ejections are a common event on the asteroid and occur all across its surface, rather than in a few select spots. Indeed, in the year since the three ejection events that are reported today in Science, Hergenrother says OSIRIS-REx has detected several other smaller ejections. ...
I watched it live, very impressive. Also like the way they are going to check the actually have a sample - stick the arm out and spin around and compare readings with the last time (pre sample) they did the same manoeuvre!Success! Yay science!
They don't know just how much of the asteroid they've collected yet, but if they didn't get enough they have plans to do the maneuver again at another site.
OSIRIS-REx Spacecraft Successfully Touches Asteroid
Yeah we always think "exciting new discovery" = alien bases or some such and NASA actually mean they've found a new crater.NASA to announce "exciting new discovery" about the moon.
It's always about water.NASA to announce "exciting new discovery" about the moon.
That looks familiar
https://www.bbc.co.uk/news/science-environment-54666328Water on the Moon could sustain a lunar base
By Victoria Gill
Science correspondent, BBC News
Published19 minutes ago
Having dropped tantalising hints days ago about an "exciting new discovery about the Moon", the US space agency has revealed conclusive evidence of water on our only natural satellite.
This "unambiguous detection of molecular water" will boost Nasa's hopes of establishing a lunar base.
The aim is to sustain that base by tapping into the Moon's natural resources.
The findings have been published as two papers in the journal Nature Astronomy.
Perhaps it’s the swimming pool for the alien bases that they’re not telling us about?So it wasn't a monolith after all...
https://www.theguardian.com/science...arecibo-space-telescope-in-puerto-rico-jungleUS to shut down famed huge Arecibo space telescope in Puerto Rico jungle
The observatory has played a key part in space exploration – and a few movies – but two accidents have rendered the 305m-wide instrument unsafe
Fri 20 Nov 2020 01.16 GMTLast modified on Fri 20 Nov 2020 17.43 GMT
A huge US space telescope nestled deep in the Puerto Rican jungle will be shut down after suffering two destructive mishaps in recent months, ending 57 years of astronomical discoveries.