I wonder what Jack Vance would have imagined of a civilisation near this Mu Cephei monster star.
Can one determine how far a planet with living creature would be.
How large this planet would be, what gravity, how long a year would be.
In the "Big planet" by Jack Vance I do not recall about it's sun(s).
Can one determine how far a planet with living creature would be.
How large this planet would be, what gravity, how long a year would be.
In the "Big planet" by Jack Vance I do not recall about it's sun(s).
I can give some idea of the distance at which a planet might form around a hypergiant star.
Astronomers have discovered a hypergiant of 70 solar masses that has a diameter exceeding the orbit of Mars.
It has what looks like planet-forming rings at distances that would lie far beyond the outer limits of our solar system.
Sun and planets not to scale - the planets would be invisible on this scale
https://www.jpl.nasa.gov/news/nasas-spitzer-uncovers-hints-of-mega-solar-systems/
Jack Vance would certainly have been interested in this discovery.
Could that be a hypergiant star in the background?
The Parker Solar Probe has survived its journey through the Sun's outer atmosphere.
The signal confirming that all systems are operating normally has been received a day earlier than expected.
A close approach of 3.8 million miles may not sound spectacular, but that's about 10 times closer than Mercury which is 36 million miles from the Sun.
The signal confirming that all systems are operating normally has been received a day earlier than expected.
A close approach of 3.8 million miles may not sound spectacular, but that's about 10 times closer than Mercury which is 36 million miles from the Sun.
There is a lot to learn about stars. Even I get confused... but I think our star is a main sequence one. OBAFGKM an' all that going from blue hot to red coolish.
Hypergiants and giants seem to be big things on another scale, wherher hot new ones or old red ones. Blue Giants are about the size of the orbit of Mercury, and get even bigger in old age like Mu Cephei aka The Garnet Star, which we discussed earlier, if they reach it.
Rigel in Orion is a Type B8 blue hypergiant:
https://en.wikipedia.org/wiki/Rigel
I suppose the actual fusion core is around the size of planet Earth, as usual. The rest is hot gas held up by heat.
I was doing some investigating of what gravity is on the surface of the Sun. Because that is what holds the 6000C hot surface gases, Hydrogen and a bit of Helium 4, in place.
Turns out it is around 25g acceleration on a radius of approx 430,000 miles. So you would weigh a couple of tons.
Of course gravity is inverse square, and the effect of gravity at 92 million miles on us is much smaller. If you mass 70 kg the effect of the Sun's gravity is apparently a mere 43 grams.
I calculate this is the mere additional mass effect of 15 teabags holding you in orbit every year, and producing solar tides and perhaps influencing your weight.
Gravity is really very interesting. It's not Isaac Newton's force, but the curvature of SpaceTime producing an upward acceleration of 1g of the surface that holds us to the ground.
And we don't live in a sphere like a baseball or a grapefruit, but on a 2-sphere surface with up and down too, as we perceive it. But that's not right either, because in some way Space is a 3 Sphere, plus time at right angles.
Naturally I am trying to visualise a 3 Sphere, which lives in a 4D Space. Just as a 2 Sphere is embedded in a 3 Space.
I have a new library book of rambling magazine articles by Carlo Rovelli which may help. It was next to the useless Brian Cox books, which I would burn if it was me running the library. Strangely it just dropped open at the page about 2 and 3 Spheres which piqued my interest:
Rovelli is also prone to ramblings about Loop Quantum Gravity, so not entirely trustworthy, but I have an open mind, and it could be worse if he was a String Theorist like Brian Cox.
But his seems a promising study, if I am to incorporate Gravity into The Standard Model. Somebody has to do it. 🙂
Hypergiants and giants seem to be big things on another scale, wherher hot new ones or old red ones. Blue Giants are about the size of the orbit of Mercury, and get even bigger in old age like Mu Cephei aka The Garnet Star, which we discussed earlier, if they reach it.
Rigel in Orion is a Type B8 blue hypergiant:
https://en.wikipedia.org/wiki/Rigel
I suppose the actual fusion core is around the size of planet Earth, as usual. The rest is hot gas held up by heat.
I was doing some investigating of what gravity is on the surface of the Sun. Because that is what holds the 6000C hot surface gases, Hydrogen and a bit of Helium 4, in place.
Turns out it is around 25g acceleration on a radius of approx 430,000 miles. So you would weigh a couple of tons.
Of course gravity is inverse square, and the effect of gravity at 92 million miles on us is much smaller. If you mass 70 kg the effect of the Sun's gravity is apparently a mere 43 grams.
I calculate this is the mere additional mass effect of 15 teabags holding you in orbit every year, and producing solar tides and perhaps influencing your weight.
Gravity is really very interesting. It's not Isaac Newton's force, but the curvature of SpaceTime producing an upward acceleration of 1g of the surface that holds us to the ground.
And we don't live in a sphere like a baseball or a grapefruit, but on a 2-sphere surface with up and down too, as we perceive it. But that's not right either, because in some way Space is a 3 Sphere, plus time at right angles.
Naturally I am trying to visualise a 3 Sphere, which lives in a 4D Space. Just as a 2 Sphere is embedded in a 3 Space.
I have a new library book of rambling magazine articles by Carlo Rovelli which may help. It was next to the useless Brian Cox books, which I would burn if it was me running the library. Strangely it just dropped open at the page about 2 and 3 Spheres which piqued my interest:
Rovelli is also prone to ramblings about Loop Quantum Gravity, so not entirely trustworthy, but I have an open mind, and it could be worse if he was a String Theorist like Brian Cox.
But his seems a promising study, if I am to incorporate Gravity into The Standard Model. Somebody has to do it. 🙂
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Ah! Topology rears its nigh on inscrutable head once again!
In topology, 2-sphere refers to the 2-dimensional surface of a usual sphere (not to be confused with a solid sphere or ball).
A common analogy is to represent the 3D Universe by the 2D surface of a round balloon. As the surface of the balloon expands, all points on the surface move away from each other illustrating that there is no centre to the expansion.
If we jump up one dimension, we can represent the 4D Universe by a 3-sphere or glome: https://polytope.miraheze.org/wiki/...ball,a 2-plane that intersects it is a circle.
Here is a visualisation of a 3-sphere or glome (not that it helps much!):
The name glome comes from the Latin "glomus" meaning "ball of string".
It's all very complicated and best left to Professionals IMO.
Rovelli reckons Dante understood General Relativity and 3-spheres from perusal of the dome roof art in the Cupola in the Baptistery in Florence:
It's a sort of M.C. Escher hyperbolic representation of the Spiritual Heavens, if you know what I mean. That disc with the shrinking fishes or bats or something.
I find this sort of thing fanciful! But will persist with his ramblings. 🙄
I was mainly pondering the smallness of the Neutron at 1 frm, which is 10^ -15 metres, and the size of the Universe at 91 Bn light years today:
This is really very good if you just go along for the ride. Er, 25 minutes, because it is a big Universe.
I was particularly interested by how big Ostriches are at 9 feet high, and that an Elephant is as big as a Red Double-Decker London bus.
This is the smallest theoretical Black Hole at 3.8 Sun Masses, and about the same size as the largest possible neutron star:
On the left is the meteorite that killed the Dinosaurs 66m years ago.
Sagittarius A* Black Hole is the size of good ol' Red Giant Arcturus,which is almost the same mass as the Sun, but a diameter 25X bigger, so not far short of the size of Mercury's orbit:
How big is the LARGEST KNOWN BLACK HOLE? Humungous! The little red dots near the smallest one are the biggest stars!
I have calculated it at 0.06 Light Years diameter, which is 122 times the distance of Pluto.
It is interesting that Black Holes get less dense as they get bigger. It works out the event horizon diameter or radius is proportional to the mass.
WHAT DOES THIS MEAN? 🤔
It means if you ad a 15 mile diameter Black Hole to another 15 Mile Black Hole, you get a 30 mile Black Hole. Add another 15 mile one and you get a 45 mile Black Hole. So if you laid all the Black Holes in the Universe end to end, and combined them, they would make a huge new one of exactly that length!
Which is a novel thought.
But mostly, we are really like ANTS. I don't know why humans think their affairs are really at all important on a Cosmic scale!
Did you know that the mass of Ants on Earth is the same as the mass of humans? So who is really running the show? 🤣
Rovelli reckons Dante understood General Relativity and 3-spheres from perusal of the dome roof art in the Cupola in the Baptistery in Florence:
It's a sort of M.C. Escher hyperbolic representation of the Spiritual Heavens, if you know what I mean. That disc with the shrinking fishes or bats or something.
I find this sort of thing fanciful! But will persist with his ramblings. 🙄
I was mainly pondering the smallness of the Neutron at 1 frm, which is 10^ -15 metres, and the size of the Universe at 91 Bn light years today:
This is really very good if you just go along for the ride. Er, 25 minutes, because it is a big Universe.
I was particularly interested by how big Ostriches are at 9 feet high, and that an Elephant is as big as a Red Double-Decker London bus.
This is the smallest theoretical Black Hole at 3.8 Sun Masses, and about the same size as the largest possible neutron star:
On the left is the meteorite that killed the Dinosaurs 66m years ago.
Sagittarius A* Black Hole is the size of good ol' Red Giant Arcturus,which is almost the same mass as the Sun, but a diameter 25X bigger, so not far short of the size of Mercury's orbit:
How big is the LARGEST KNOWN BLACK HOLE? Humungous! The little red dots near the smallest one are the biggest stars!
I have calculated it at 0.06 Light Years diameter, which is 122 times the distance of Pluto.
It is interesting that Black Holes get less dense as they get bigger. It works out the event horizon diameter or radius is proportional to the mass.
WHAT DOES THIS MEAN? 🤔
It means if you ad a 15 mile diameter Black Hole to another 15 Mile Black Hole, you get a 30 mile Black Hole. Add another 15 mile one and you get a 45 mile Black Hole. So if you laid all the Black Holes in the Universe end to end, and combined them, they would make a huge new one of exactly that length!
Which is a novel thought.
But mostly, we are really like ANTS. I don't know why humans think their affairs are really at all important on a Cosmic scale!
Did you know that the mass of Ants on Earth is the same as the mass of humans? So who is really running the show? 🤣
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Well, whatever... if anyone understands this stuff, let me know! 🙂
https://en.wikipedia.org/wiki/Observable_universe
Anywhoo, I have done further calculations.
Recall the Neutron or Proton is 1 fm or 10^ -15m.
How big is the Universe if it is 93 Bn ly across in metres? See I have corrected the figure.
8.83 x 10^ 26 m! Recall you are about 2 m tall. 🙂
Or 28.5 Gpc (GigaParsecs) which is less easy to grasp.
As the resident Astrophysicist at my watering hole, Brent was excited to inform me that all Seven Planets will line up on January 25th 2025.
"Where did you find this information, Brent?" 🙄
"Er, FACEBOOK!" 🙂
"Hmm, reeks of Dubiousness and Astrology to me..." 🙁
Turns out he is right after a fashion, according to Forbes:
Mercury is, crucially, missing of course. As it goes, because I have dabbled in the Black Arts, my sister, a Virgo, was born with all seven Planets ascendant.
Very favourable, apparently. Very talented woman.
Times of India presents the Horoscope predictions too:
Cosmic Catalyst for change! Sounds like a good day for betting on the horses and winning for a change... 🤣
https://en.wikipedia.org/wiki/Observable_universe
Anywhoo, I have done further calculations.
Recall the Neutron or Proton is 1 fm or 10^ -15m.
How big is the Universe if it is 93 Bn ly across in metres? See I have corrected the figure.
8.83 x 10^ 26 m! Recall you are about 2 m tall. 🙂
Or 28.5 Gpc (GigaParsecs) which is less easy to grasp.
As the resident Astrophysicist at my watering hole, Brent was excited to inform me that all Seven Planets will line up on January 25th 2025.
"Where did you find this information, Brent?" 🙄
"Er, FACEBOOK!" 🙂
"Hmm, reeks of Dubiousness and Astrology to me..." 🙁
Turns out he is right after a fashion, according to Forbes:
Mercury is, crucially, missing of course. As it goes, because I have dabbled in the Black Arts, my sister, a Virgo, was born with all seven Planets ascendant.
Very favourable, apparently. Very talented woman.
Times of India presents the Horoscope predictions too:
Cosmic Catalyst for change! Sounds like a good day for betting on the horses and winning for a change... 🤣
It is the bacteria that are running the show!
Humans couldn't live without them: https://www.livescience.com/32761-good-bacteria-boost-immune-system.html
And look at how much of the Earth's biomass they represent compared to animals, of which humans are but a tiny subset!
Plants: 450 Gt C
Bacteria: 70 Gt C
Animals: 2 Gt C
Above, biomass is measured in terms of carbon, and thus independent of water content (Gt C = gigatons of carbon).
A rare clearish night in Portsmouth had me down the seafront at 10PM tonight. It was so cold that my little fingers couldn't feel the camera button. The Light pollution was dreadful as usual. And I had the wrong lens fitted after Christmas snaps.
But I discovered a smudge on my slightly blurry photos that turns out the Beehive Cluster M44 below Mars and the Twins, Castor and Pollux and getting into the dim constellation of Cancer.
https://en.wikipedia.org/wiki/Beehive_Cluster
This website is good for star and planet maps:
https://theskylive.com/
Mars is to the left of bright Jupiter at the moment in Gemini, and near the end of the month will be as bright as Sirius at -1.5.
This thing is 600 ly away and consists of 1000 stars. It is three times as big as the full moon at 11 ly across apparently.
But I discovered a smudge on my slightly blurry photos that turns out the Beehive Cluster M44 below Mars and the Twins, Castor and Pollux and getting into the dim constellation of Cancer.
https://en.wikipedia.org/wiki/Beehive_Cluster
This website is good for star and planet maps:
https://theskylive.com/
Mars is to the left of bright Jupiter at the moment in Gemini, and near the end of the month will be as bright as Sirius at -1.5.
This thing is 600 ly away and consists of 1000 stars. It is three times as big as the full moon at 11 ly across apparently.
Thought I could do better on the Beehive Cluster picture at home with the better lens which has a focus scale. 50mm (effectively 75mm), f2.5, 3 seconds, ASA 800.
That's Mars top right.
This is the very similar Wikipedia picture, so I think I got it.
Comes out reddish at preset optimum, bluer with a slightly shorter focal length. But happy with that.
That's Mars top right.
This is the very similar Wikipedia picture, so I think I got it.
Comes out reddish at preset optimum, bluer with a slightly shorter focal length. But happy with that.
You certainly got it Steve, but I'm rather concerned about you being out in the bitter cold of a winter's night all on your own.
Don't you think it's time you started to "Beehive" yourself? 😀
The most prominent open star cluster in the Milky Way is, of course,the Pleiades.
I followed on from your Wikipedia link to discover that it was the clergyman John Mitchell who, in 1767, established that the stars in a cluster are physically related and not just the result of a chance alignment as seen from Earth.
John Mitchell is considered "one of the greatest unsung scientists of all time", being the first person to have proposed
- the existence of massive stellar bodies from which light would not be able to escape
- that earthquakes travel in waves and involve the offsets of faults
- that double stars are a product of mutual gravitation
- the inverse square law of magnetism and a method of manufacturing artificial magnets
- a torsion balance for measuring the mass of the Earth as later employed by Cavendish
There was a rather fine conjunction of the crescent Moon and Venus tonight quite high up in the twilight of the Southwest with a rare clear sky.
Naturally I pointed it out to my cronies at the watering hole.
I got an inadvertent snap of the Pleiades last night. You can see Jupiter and its moon Callisto top left, red giant Aldebaran in Taurus on the left:
I learn that Galileo liked the Pleiades (400 ly away) along with the moons of Jupiter:
https://en.wikipedia.org/wiki/Pleiades
Can you name the Seven Sisters?
We can now. Sterope 1 and 2 aka Asterope. Every day a School Day. 😎
Naturally I pointed it out to my cronies at the watering hole.
I got an inadvertent snap of the Pleiades last night. You can see Jupiter and its moon Callisto top left, red giant Aldebaran in Taurus on the left:
I learn that Galileo liked the Pleiades (400 ly away) along with the moons of Jupiter:
https://en.wikipedia.org/wiki/Pleiades
Can you name the Seven Sisters?
We can now. Sterope 1 and 2 aka Asterope. Every day a School Day. 😎
Yes, the crescent Moon and nearby Venus put on a dazzling display in the darkening sky.
When looking at the Pleiades, most people see six, not seven, stars.
You'll remember that in modern Japan the Pleiades cluster is known as Subaru, and the six brightest stars are depicted in the Subaru car logo.
When looking at the Pleiades, most people see six, not seven, stars.
You'll remember that in modern Japan the Pleiades cluster is known as Subaru, and the six brightest stars are depicted in the Subaru car logo.
I've always wondered about which stars were "the seven" in the Pleiades, I've seen six or eight+ depending on whether I'm looking naked eye or through binoculars.
TheSubaru logo reminds me I programmed a Corvus Concept computer for a short while. Corvus (better known for its hard disk drives and networking systems) had some constellation as its logo:
https://en.wikipedia.org/wiki/Corvus_Systems
https://commons.wikimedia.org/wiki/File:Corvus_Systems_logo.svg
I don't remember if I ever knew what constellation that was.
The
https://en.wikipedia.org/wiki/Corvus_Systems
https://commons.wikimedia.org/wiki/File:Corvus_Systems_logo.svg
I don't remember if I ever knew what constellation that was.
Pictures or it didn't happen, eh?
The Greek tale of Corvus the Crow or Raven tuns out to be a more shocking story than the typical Christmas edition of "Eastenders"!
The God Apollo, being smitten with the lovely Coronis, sends a Crow to spy on her, and make sure she is being faithful. The Crow, being an intelligent creature who is not easily fooled, reports that she has a "thing" going on with a mere mortal!
You can imagine Apollo's feelings of Godly wrath! He will never be able to show his face in the Olympian version of The Queen Vic Pub again, without the other Gods tittering.
Coronis takes a swim with the fishes...
The Crow gets immortalised for reward as a Constellation. But I think he was a rotten little GRASS. Phil Mitchell would have filled him in. 🤣
Patrick Moore says there are no interesting objects in Corvus. But he is wrong. Just North is the M104 Sombrero Galaxy:
And to the right are The Antennae Galaxies, which are colliding as we discussed earlier.
The Greek tale of Corvus the Crow or Raven tuns out to be a more shocking story than the typical Christmas edition of "Eastenders"!
The God Apollo, being smitten with the lovely Coronis, sends a Crow to spy on her, and make sure she is being faithful. The Crow, being an intelligent creature who is not easily fooled, reports that she has a "thing" going on with a mere mortal!
You can imagine Apollo's feelings of Godly wrath! He will never be able to show his face in the Olympian version of The Queen Vic Pub again, without the other Gods tittering.
Coronis takes a swim with the fishes...
The Crow gets immortalised for reward as a Constellation. But I think he was a rotten little GRASS. Phil Mitchell would have filled him in. 🤣
Patrick Moore says there are no interesting objects in Corvus. But he is wrong. Just North is the M104 Sombrero Galaxy:
And to the right are The Antennae Galaxies, which are colliding as we discussed earlier.
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An image of the Corvus Systems logo is shown in benb's second link, but I've found one elsewhere that I could copy and paste.
This Greek Mythology sure is complicated! I learn that Maia ( A sea nymph) in the Pleiades is associated with the month of May, as is the whole of Taurus.
Taurus is on the whole associated with rain. This is unsurprising since it rises in the dawn in April, famous for "Her Shoures Soote" by Mr. Chaucer.
The ill-fated Coronis was one of the five Hyades, or rain nymphs, associated with rain and weepiness. The Hyades are 5 stars that make up the head of the Bull, here snapped by yours truly with Jupiter:
What I noticed is the Hyades at 150 ly look red in all my snaps. This is because they ARE red! 🙂
The five bright ones are all reddish type G and K giants. I really don't know if Aldebaran at 70 ly is considered one of the Hyades.
https://en.wikipedia.org/wiki/Hyades_(star_cluster)
Whereas the Pleiades at 400 ly on the right are mostly Blue B types. OBAFGKM and all that and look white in my snaps. Apparently, the gas clouds around the Pleiades are just a gassy region of space they are currently moving through.
FWIW, Ursa Major (The Big Dipper aka The Plough) at 70 ly is another cluster, with many stars moving in the same direction.
This gets complicated, but it means the Hyades are older stars than the Pleiades, and the really big stars are long exploded, and old red stars are dominating a smaller main sequence of stars.
You can see the reddishness of the Hyades even more clearly in my photo a few posts back, rising over our house. It is surprising what you can work out about the galaxy even with a lowly camera. 😎
Taurus is on the whole associated with rain. This is unsurprising since it rises in the dawn in April, famous for "Her Shoures Soote" by Mr. Chaucer.
The ill-fated Coronis was one of the five Hyades, or rain nymphs, associated with rain and weepiness. The Hyades are 5 stars that make up the head of the Bull, here snapped by yours truly with Jupiter:
What I noticed is the Hyades at 150 ly look red in all my snaps. This is because they ARE red! 🙂
The five bright ones are all reddish type G and K giants. I really don't know if Aldebaran at 70 ly is considered one of the Hyades.
https://en.wikipedia.org/wiki/Hyades_(star_cluster)
Whereas the Pleiades at 400 ly on the right are mostly Blue B types. OBAFGKM and all that and look white in my snaps. Apparently, the gas clouds around the Pleiades are just a gassy region of space they are currently moving through.
FWIW, Ursa Major (The Big Dipper aka The Plough) at 70 ly is another cluster, with many stars moving in the same direction.
This gets complicated, but it means the Hyades are older stars than the Pleiades, and the really big stars are long exploded, and old red stars are dominating a smaller main sequence of stars.
You can see the reddishness of the Hyades even more clearly in my photo a few posts back, rising over our house. It is surprising what you can work out about the galaxy even with a lowly camera. 😎
Complicated no doubt, but open star clusters provide the ideal environment for astronomers to investigate the birth and death of stars.
I've edited some facts I've discovered that relate to your astronomical observations:
- The Big Dipper, with its sprawling pattern of stars, is part of a drifting open cluster known as the Ursa Major Moving Cluster.
- The Pleiades cluster, once known as the Seven Sisters, now has six stars visible to the naked eye due to the drifting of the stars.
- The Hyades Cluster contains about 400 stars, five of which form a 'V' shape that is visible to the naked eye.
I don't find the explanation of drifting stars explaining six or seven sisters at all convincing:
This is 100,000 years back. Hardly different. All this myth stuff is pure fantasy anyway. They is what they is!
I was out tonight. Half moon, so not ideal. But I snapped Uranus again. It is just starting to move East again after being retrograde for months.
Quite the miracle that Herschel even spotted it at magnitude 5.7 around 1780. He and his sister must have really known their stars.
The very bright Gibbous Moon is due to pass through the Pleiades on Thursday night in North America. The Moon is about 30 arc minutes or half a degree and moves its width in an hour, Will look a bit like this different occultation:
Gives you an idea of scale, anyway. And that the Moon's orbit is considerably (5 degrees?) inclined to the ecliptic. Stargazing will be hopeless for the next week or so due to the sky glare of the Moon.
This is 100,000 years back. Hardly different. All this myth stuff is pure fantasy anyway. They is what they is!
I was out tonight. Half moon, so not ideal. But I snapped Uranus again. It is just starting to move East again after being retrograde for months.
Quite the miracle that Herschel even spotted it at magnitude 5.7 around 1780. He and his sister must have really known their stars.
The very bright Gibbous Moon is due to pass through the Pleiades on Thursday night in North America. The Moon is about 30 arc minutes or half a degree and moves its width in an hour, Will look a bit like this different occultation:
Gives you an idea of scale, anyway. And that the Moon's orbit is considerably (5 degrees?) inclined to the ecliptic. Stargazing will be hopeless for the next week or so due to the sky glare of the Moon.