APOD: Andromeda Station (2020 Mar 26)

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APOD: Andromeda Station (2020 Mar 26)

Post by APOD Robot » Thu Mar 26, 2020 4:05 am

Image Andromeda Station

Explanation: This surreal picture isn't from a special effects sci-fi movie. It is a digital composite of frames of the real Andromeda Galaxy, also known as M31, rising over a real mountain. Exposures tracking the galaxy and background stars have been digitally combined with separate exposures of the foreground terrain. All background and foreground exposures were made back to back with the same camera and telephoto lens on the same night from the same location. In the "Deepscape" combination they produce a stunning image that reveals a range of brightness and color that your eye can't quite see on its own. Still, it does look like you could ride a cable car up this mountain and get off at the station right next to Andromeda. But at 2.5 million light-years from Earth the big beautiful spiral galaxy really is a little out of reach as a destination. Don't worry, though. Just wait 5 billion years and the Andromeda Galaxy will come to you. This Andromeda Station is better known as Weisshorn, the highest peak of the ski area in Arosa, Switzerland.

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by jks » Thu Mar 26, 2020 4:39 am

I apologize for my recent postings of apparent problems but I have another one (I think).

I usually click on the image in order to either zoom in, or to sometimes see a wider view, but for today's APOD I get the dreaded:

"Not Found

The requested URL /apod/image/2003/AndromedaStation.jpg was not found on this server."

I tried my phone (Wi-Fi off) and I get the same thing. Clicking on the image for yesterday's APOD works just fine.

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by Ann » Thu Mar 26, 2020 5:14 am

jks wrote:
Thu Mar 26, 2020 4:39 am
I apologize for my recent postings of apparent problems but I have another one (I think).

I usually click on the image in order to either zoom in, or to sometimes see a wider view, but for today's APOD I get the dreaded:

"Not Found

The requested URL /apod/image/2003/AndromedaStation.jpg was not found on this server."

I tried my phone (Wi-Fi off) and I get the same thing. Clicking on the image for yesterday's APOD works just fine.
I, too, got the "Not Found" message when I clicked on the APOD to enlarge it. So the problem is with the APOD itself. Or let's put it like this: There is no larger version of today's APOD currently available.

Ann
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Re: APOD: Andromeda Station (2020 Mar 26)

Post by Boomer12k » Thu Mar 26, 2020 5:33 am

Maybe a larger version was not added??

There are so many stars... it looks like Van Gogh painted with swirls... but with DOTS...
It "sweeps" around the sky, and amazing detail...

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by orin stepanek » Thu Mar 26, 2020 11:17 am

WOW!
AndromedaStation1049.jpg
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Orin

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by neufer » Thu Mar 26, 2020 12:06 pm

https://en.wikipedia.org/wiki/Arosa wrote:

<<Arosa was established as a health resort by a German doctor in 1883, and the first sanatorium was opened in 1888. From 1900 on it gradually developed as a winter resort. In 1938 the first ski lifts were built, and in 1956 the Weisshorn cable car was opened.

Skiing in Switzerland received a big boost from Sir Arthur Conan Doyle, author of the Sherlock Holmes series. Conan Doyle, an avid sportsman, was wintering in Davos. For entertainment, he ordered some skiing "boards" from Norway and hiked up the mountain with two local guides. They then skied down into Arosa, ending their journey with a luncheon at a local inn, the Seehof, the first hotel in Arosa. Conan Doyle wrote of his pioneering Davos/Arosa ski adventure in a British magazine, The Strand, in 1894, and the story attracted British skiers to Switzerland.

Erwin Schrödinger was vacationing in Arosa at Christmas 1925 when he made his breakthrough discovery of wave mechanics.

In 1933, Thomas Mann stayed in Arosa during the first week of his Swiss exile.

On 20 February 1940, Germany's Hassall met with British J. Lonsdale Bryant in Arosa, to make a plan to overthrow the ruling German Nazi Adolf Hitler.>>
https://www.goodreads.com/quotes/tag/sherlock-holmes wrote:


“Holmes and Watson are on a camping trip. In the middle of the night Holmes wakes up and gives Dr. Watson a nudge. "Watson" he says, "look up in the sky and tell me what you see."

"I see millions of stars, Holmes," says Watson.

"And what do you conclude from that, Watson?"

Watson thinks for a moment. "Well," he says, "astronomically, it tells me that there are millions of galaxies and potentially billions of planets. Astrologically, I observe that Saturn is in Leo. Horologically, I deduce that the time is approximately a quarter past three. Meterologically, I suspect that we will have a beautiful day tomorrow. Theologically, I see that God is all-powerful, and we are small and insignficant. Uh, what does it tell you, Holmes?"

"Watson, you idiot! Someone has stolen our tent!”

― Thomas Cathcart, Daniel Klein
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Re: APOD: Andromeda Station (2020 Mar 26)

Post by NCTom » Thu Mar 26, 2020 12:45 pm

Neufer, your additions to this site are priceless! Have to share this with my nerd and preacher friends.

Bill Bruehl

Re: APOD: Andromeda Station (2020 Mar 26)

Post by Bill Bruehl » Thu Mar 26, 2020 1:16 pm

I am an innocent about astronomical science, but every day I awake, brush my teeth, then link to APOD before doing anything else. Time after time I see a combination of art, aesthetics, science, and engineering that most other people in our culture are incapable of either understanding or doing. And today's ANDROMEDA STATION stands at the top of my list in all those departments.

I have two questions when I look at Andromeda––as well as all galaxies–– what is the depth of the galaxy in light-years and does the energy created by the black hole in the center exit our cosmos? Please. :D

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by Cousin Ricky » Thu Mar 26, 2020 1:33 pm

APOD Robot wrote:
Thu Mar 26, 2020 4:05 am
But at 2.5 million light-years from Earth the big beautiful spiral galaxy really is a little out of reach as a destination. Don't worry, though. Just wait 5 billion years and the Andromeda Galaxy will come to you.
Nighttime Sky View of Future Galaxy Merger: 7 Billion Years

From which planet? Won’t the Sun have swallowed up the Earth by then?

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by Cousin Ricky » Thu Mar 26, 2020 1:40 pm

Ann wrote:
Thu Mar 26, 2020 5:14 am
jks wrote:
Thu Mar 26, 2020 4:39 am
I apologize for my recent postings of apparent problems but I have another one (I think).

I usually click on the image in order to either zoom in, or to sometimes see a wider view, but for today's APOD I get the dreaded:

"Not Found

The requested URL /apod/image/2003/AndromedaStation.jpg was not found on this server."

I tried my phone (Wi-Fi off) and I get the same thing. Clicking on the image for yesterday's APOD works just fine.
I, too, got the "Not Found" message when I clicked on the APOD to enlarge it. So the problem is with the APOD itself. Or let's put it like this: There is no larger version of today's APOD currently available.

Ann
You can get piecemeal previews in ridiculously high resolution at Ralf Rohner’s website.

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by CuriousChimp » Thu Mar 26, 2020 2:06 pm

APOD Robot wrote:
Thu Mar 26, 2020 4:05 am

... Don't worry, though. Just wait 5 billion years and the Andromeda Galaxy will come to you. ...
I keep seeing this assertion but I don't like it. I don't know why but I'm very dubious about it.

Are we sure that our big bully of a neighbour is coming here? Are we certain she's part of the Milky Way Local Group, even? Might it not be that The Lady is the core galaxy of her own local group and that they are just passing by?

There are many, many fine examples, and APoD shows lots of the prettier ones, of pairs and multiples of huge star clouds whizzing by each other without being related. Might lovely Andromeda and us be one of those?

If not, why am I so sceptical?

Another weird thought ... five milliards of years is a strangely specific number. By an interesting coincidence it is also roughly the expected lifespan of Sol, that shiny, bright thing that keeps us all cosy and warm. With a possible galactic-sized catastrophe and the end of our Sun coming it is almost as though the cosmos is waving a sign at us; telling us to get the hades out of here before it smooshes us.

I wonder whether Man is clever enough to see the signs and to heed them? :)

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by CuriousChimp » Thu Mar 26, 2020 2:16 pm

Cousin Ricky wrote:
Thu Mar 26, 2020 1:33 pm
APOD Robot wrote:
Thu Mar 26, 2020 4:05 am
But at 2.5 million light-years from Earth the big beautiful spiral galaxy really is a little out of reach as a destination. Don't worry, though. Just wait 5 billion years and the Andromeda Galaxy will come to you.
Nighttime Sky View of Future Galaxy Merger: 7 Billion Years

From which planet? Won’t the Sun have swallowed up the Earth by then?
Uhnnn. Sorry, I really should read the other comments before bloviating unwisely.

To answer the posed question: from no planet. Humans are not going anywhere. Not ever. Nor does it seem likely that the species or its children will have anything like a civilisation in mere centuries never mind gigayears.

Even were Civilisation to survive, our inheritors would be nothing even remotely like Human. Not in seven milliards of years time. The children of Man, were they to have taken the steps into the darkness would be far more different from us than any alien we have ever imagined.

They probably wouldn't even remember us.

The cosmos is vast, Time is deep and there is room for many things to happen. One thing that will not is us leaving this world, which is ever so sad.

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by Chris Peterson » Thu Mar 26, 2020 2:22 pm

Bill Bruehl wrote:
Thu Mar 26, 2020 1:16 pm
I have two questions when I look at Andromeda––as well as all galaxies–– what is the depth of the galaxy in light-years and does the energy created by the black hole in the center exit our cosmos?
This is a fairly typical large spiral galaxy. Think of it as a disk of stars about 200,000 ly in diameter and no more than a few thousand ly thick. In the center of this disk is a nearly spherical bulge of stars maybe 10,000 ly in diameter.

No energy is created by the central black hole.
Chris

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by Chris Peterson » Thu Mar 26, 2020 2:30 pm

CuriousChimp wrote:
Thu Mar 26, 2020 2:06 pm
APOD Robot wrote:
Thu Mar 26, 2020 4:05 am

... Don't worry, though. Just wait 5 billion years and the Andromeda Galaxy will come to you. ...
I keep seeing this assertion but I don't like it. I don't know why but I'm very dubious about it.

Are we sure that our big bully of a neighbour is coming here? Are we certain she's part of the Milky Way Local Group, even? Might it not be that The Lady is the core galaxy of her own local group and that they are just passing by?
Yes, we are sure that the two galaxies are on a collision course, and we're sure that both Andromeda and the Milky Way are part of the same cluster. We can measure the mass of Andromeda with reasonable accuracy, and we can measure its velocity with reasonable accuracy. Enough to determine that our galaxies are gravitationally bound in mutual closed orbits. In all such cases, the end result is merger.
There are many, many fine examples, and APoD shows lots of the prettier ones, of pairs and multiples of huge star clouds whizzing by each other without being related.
I don't think so. There are images of the sky with lone galaxies and distant background galaxies. But all of the images with gravitationally bound galaxies- galaxies that are close to each other- we see interaction. Depending on their orbits, galaxies may orbit each other for a long time, gradually disrupting each other as they spiral closer together, eventually ending in mergers. A lot of angular momentum needs to be transferred, and if the orbital eccentricities are low, this may take tens of billions of years. But it's inevitable in any cluster.
Chris

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by bystander » Thu Mar 26, 2020 2:36 pm

Ann wrote:
Thu Mar 26, 2020 5:14 am
jks wrote:
Thu Mar 26, 2020 4:39 am
I apologize for my recent postings of apparent problems but I have another one (I think).

I usually click on the image in order to either zoom in, or to sometimes see a wider view, but for today's APOD I get the dreaded:

"Not Found

The requested URL /apod/image/2003/AndromedaStation.jpg was not found on this server."

I tried my phone (Wi-Fi off) and I get the same thing. Clicking on the image for yesterday's APOD works just fine.
I, too, got the "Not Found" message when I clicked on the APOD to enlarge it. So the problem is with the APOD itself. Or let's put it like this: There is no larger version of today's APOD currently available.

Ann
Try Andromeda%20Station.jpg
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A 'thruple'

Post by neufer » Thu Mar 26, 2020 2:57 pm

Chris Peterson wrote:
Thu Mar 26, 2020 2:30 pm
CuriousChimp wrote:
Thu Mar 26, 2020 2:06 pm
APOD Robot wrote:
Thu Mar 26, 2020 4:05 am

... Don't worry, though. Just wait 5 billion years and the Andromeda Galaxy will come to you. ...
I keep seeing this assertion but I don't like it. I don't know why but I'm very dubious about it.

Are we sure that our big bully of a neighbour is coming here? Are we certain she's part of the Milky Way Local Group, even? Might it not be that The Lady is the core galaxy of her own local group and that they are just passing by?
Yes, we are sure that the two galaxies are on a collision course, and we're sure that both Andromeda and the Milky Way are part of the same cluster. We can measure the mass of Andromeda with reasonable accuracy, and we can measure its velocity with reasonable accuracy. Enough to determine that our galaxies are gravitationally bound in mutual closed orbits. In all such cases, the end result is merger.
https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision#Certainty wrote:
<<The Andromeda Galaxy is approaching the Milky Way at about 110 kilometres per second as indicated by blueshift. However, the lateral speed (measured as proper motion) is very difficult to measure with a precision to draw reasonable conclusions: a lateral speed of only 7.7 km/s would mean that the Andromeda Galaxy is moving toward a point 177,800 light-years to the side of the Milky Way ((7.7 km/s) / (110 km/s) × (2,540,000 ly)), and such a speed over an eight-year timeframe amounts to only 1/3,000th of a Hubble Space Telescope pixel (Hubble's resolution≈0.05 arcsec: (7.7 km/s)/(300,000 km/s)×(8 y)/(2,540,000 ly)×180°/π×3600 = 0.000017 arcsec). Until 2012, it was not known whether the possible collision was definitely going to happen or not. In 2012, researchers concluded that the collision is sure using Hubble to track the motion of stars in Andromeda between 2002 and 2010 with sub-pixel accuracy. Andromeda's tangential or sideways velocity with respect to the Milky Way was found to be much smaller than the speed of approach and therefore it is expected that it will directly collide with the Milky Way in around four and a half billion years.

The studies also suggest that M33, the Triangulum Galaxy—the third-largest and third-brightest galaxy of the Local Group—will participate in the collision event, too. Its most likely fate is to end up orbiting the merger remnant of the Milky Way and Andromeda galaxies and finally to merge with it in an even more distant future. However, a collision with the Milky Way, before it collides with the Andromeda Galaxy, or an ejection from the Local Group cannot be ruled out.>>
Art Neuendorffer

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Re: A 'thruple'

Post by Chris Peterson » Thu Mar 26, 2020 3:08 pm

neufer wrote:
Thu Mar 26, 2020 2:57 pm
Chris Peterson wrote:
Thu Mar 26, 2020 2:30 pm
CuriousChimp wrote:
Thu Mar 26, 2020 2:06 pm


I keep seeing this assertion but I don't like it. I don't know why but I'm very dubious about it.

Are we sure that our big bully of a neighbour is coming here? Are we certain she's part of the Milky Way Local Group, even? Might it not be that The Lady is the core galaxy of her own local group and that they are just passing by?
Yes, we are sure that the two galaxies are on a collision course, and we're sure that both Andromeda and the Milky Way are part of the same cluster. We can measure the mass of Andromeda with reasonable accuracy, and we can measure its velocity with reasonable accuracy. Enough to determine that our galaxies are gravitationally bound in mutual closed orbits. In all such cases, the end result is merger.
https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision#Certainty wrote:
<<The Andromeda Galaxy is approaching the Milky Way at about 110 kilometres per second as indicated by blueshift. However, the lateral speed (measured as proper motion) is very difficult to measure with a precision to draw reasonable conclusions: a lateral speed of only 7.7 km/s would mean that the Andromeda Galaxy is moving toward a point 177,800 light-years to the side of the Milky Way ((7.7 km/s) / (110 km/s) × (2,540,000 ly)), and such a speed over an eight-year timeframe amounts to only 1/3,000th of a Hubble Space Telescope pixel (Hubble's resolution≈0.05 arcsec: (7.7 km/s)/(300,000 km/s)×(8 y)/(2,540,000 ly)×180°/π×3600 = 0.000017 arcsec). Until 2012, it was not known whether the possible collision was definitely going to happen or not. In 2012, researchers concluded that the collision is sure using Hubble to track the motion of stars in Andromeda between 2002 and 2010 with sub-pixel accuracy. Andromeda's tangential or sideways velocity with respect to the Milky Way was found to be much smaller than the speed of approach and therefore it is expected that it will directly collide with the Milky Way in around four and a half billion years.

The studies also suggest that M33, the Triangulum Galaxy—the third-largest and third-brightest galaxy of the Local Group—will participate in the collision event, too. Its most likely fate is to end up orbiting the merger remnant of the Milky Way and Andromeda galaxies and finally to merge with it in an even more distant future. However, a collision with the Milky Way, before it collides with the Andromeda Galaxy, or an ejection from the Local Group cannot be ruled out.>>
A collision is certain- what isn't certain (although the certainty is high) is that a collision will happen at the next periapsis. And an ejection is only possible if the two bodies pass so close together that their outer regions collide, and they undergo significant tidal disruption.
Chris

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by Chris Peterson » Thu Mar 26, 2020 3:11 pm

bystander wrote:
Thu Mar 26, 2020 2:36 pm
Ann wrote:
Thu Mar 26, 2020 5:14 am
jks wrote:
Thu Mar 26, 2020 4:39 am
I apologize for my recent postings of apparent problems but I have another one (I think).

I usually click on the image in order to either zoom in, or to sometimes see a wider view, but for today's APOD I get the dreaded:

"Not Found

The requested URL /apod/image/2003/AndromedaStation.jpg was not found on this server."

I tried my phone (Wi-Fi off) and I get the same thing. Clicking on the image for yesterday's APOD works just fine.
I, too, got the "Not Found" message when I clicked on the APOD to enlarge it. So the problem is with the APOD itself. Or let's put it like this: There is no larger version of today's APOD currently available.

Ann
Try Andromeda%20Station.jpg
https://apod.nasa.gov/apod/image/2003/A ... tation.jpg
Chris

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by johnnydeep » Thu Mar 26, 2020 3:12 pm

neufer wrote:
Thu Mar 26, 2020 12:06 pm

"I see millions of stars, Holmes," says Watson.

"And what do you conclude from that, Watson?"

Watson thinks for a moment. "Well," he says, "astronomically, it tells me that there are millions of galaxies and potentially billions of planets.
The entire quote is pretty darn funny, but the nerd in me has a problem with deducing that there are millions of galaxies from seeing millions of stars in the sky. It just doesn't follow.

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by Ann » Thu Mar 26, 2020 3:20 pm

CuriousChimp wrote:
Thu Mar 26, 2020 2:06 pm
APOD Robot wrote:
Thu Mar 26, 2020 4:05 am

... Don't worry, though. Just wait 5 billion years and the Andromeda Galaxy will come to you. ...
I keep seeing this assertion but I don't like it. I don't know why but I'm very dubious about it.

Are we sure that our big bully of a neighbour is coming here? Are we certain she's part of the Milky Way Local Group, even? Might it not be that The Lady is the core galaxy of her own local group and that they are just passing by?

There are many, many fine examples, and APoD shows lots of the prettier ones, of pairs and multiples of huge star clouds whizzing by each other without being related. Might lovely Andromeda and us be one of those?

If not, why am I so sceptical?

Another weird thought ... five milliards of years is a strangely specific number. By an interesting coincidence it is also roughly the expected lifespan of Sol, that shiny, bright thing that keeps us all cosy and warm. With a possible galactic-sized catastrophe and the end of our Sun coming it is almost as though the cosmos is waving a sign at us; telling us to get the hades out of here before it smooshes us.

I wonder whether Man is clever enough to see the signs and to heed them? :)
As Chris said, practically all galaxies that are of similar resolution and moderately similar size, and are close together on the sky, show signs of interaction. A fine example is the M81/ M82/ NGC 3077 trio.


























There is no doubting the interaction between these three galaxies. We have every reason to believe that there are already signs of interaction between Andromeda and the Milky Way, even though the signs are probably still subtle.

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by neufer » Thu Mar 26, 2020 4:34 pm

johnnydeep wrote:
Thu Mar 26, 2020 3:12 pm
neufer wrote:
Thu Mar 26, 2020 12:06 pm

"I see millions of stars, Holmes," says Watson.

"And what do you conclude from that, Watson?"

Watson thinks for a moment. "Well," he says, "astronomically, it tells me that there are millions of galaxies and potentially billions of planets.
The entire quote is pretty darn funny, but the nerd in me has a problem with deducing that there are millions of galaxies from seeing millions of stars in the sky. It just doesn't follow.
  • If Watson has good enough eyesight to "see millions of stars" then
    I wouldn't dare question his insight to deduce "that there are millions of galaxies."
https://www.etymonline.com/search?q=galaxy wrote:

<<galaxy (n.) late 14c., from French galaxie or directly from Late Latin galaxias "the Milky Way" as a feature in the night sky (in classical Latin via lactea or circulus lacteus), from Greek galaxias (adj.), in galaxias kyklos, literally "milky circle," from gala (genitive galaktos) "milk."

The technical astronomical sense in reference to the discrete stellar aggregate including the sun and all visible stars emerged by 1848. Figurative sense of "brilliant assembly of persons" is from 1580s. Milky Way is a translation of Latin via lactea.
Chaucer in _House of Fame_ wrote:
  • See yonder, lo, the Galaxyë
    Which men clepeth the Milky Wey,
    For hit is whyt.
Originally ours was the only one known. Astronomers began to speculate by mid-19c. that some of the spiral nebulae they could see in telescopes were actually immense and immensely distant structures the size and shape of the Milky Way.>>
Art Neuendorffer

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by neufer » Thu Mar 26, 2020 4:53 pm

Ann wrote:
Thu Mar 26, 2020 3:20 pm

As Chris said, practically all galaxies that are of similar resolution and moderately similar size, and are close together on the sky, show signs of interaction. A fine example is the M81/ M82/ NGC 3077 trio.

There is no doubting the interaction between these three galaxies. We have every reason to believe that there are already signs of interaction between Andromeda and the Milky Way, even though the signs are probably still subtle.
M82 & M81 are ~10 times closer than M31 & the Milky Way.

Tidal force scale as the inverse cube of the distance.

Ergo, M82 & M81 tidal forces are ~1,000 times stronger than tidal forces between M31 & the Milky Way.

Also, M82 & M81 have probably already had a closer encounter:
https://en.wikipedia.org/wiki/Messier_82 wrote:
<<M82 is being physically affected by its larger neighbor, the spiral M81. Ignoring any difference in their respective distances from the Earth, the centers of M81 and M82 are visually separated by about 130,000 light-years. The actual separation is 300 kly. Tidal forces caused by gravity have deformed M82, a process that started about 100 million years ago. This interaction has caused star formation to increase tenfold compared to "normal" galaxies.

M82 has undergone at least one tidal encounter with M81 resulting in a large amount of gas being funneled into the galaxy's core over the last 200 Myr. The most recent such encounter is thought to have happened around 2–5×108 years ago and resulted in a concentrated starburst together with a corresponding marked peak in the cluster age distribution. This starburst ran for up to ~50 Myr at a rate of ~10 M⊙ per year. Two subsequent starbursts followed, the last (~4–6 Myr ago) of which may have formed the core clusters, both super star clusters (SSCs) and their lighter counterparts.

Stars in M82's disk seem to have been formed in a burst 500 million years ago, leaving its disk littered with hundreds of clusters with properties similar to globular clusters (but younger), and stopped 100 million years ago with no star formation taking place in this galaxy outside the central starburst and, at low levels since 1 billion years ago, on its halo. A suggestion to explain those features is that M82 was previously a low surface brightness galaxy where star formation was triggered due to interactions with its giant neighbor.>>
Art Neuendorffer

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by GeoXXX » Thu Mar 26, 2020 5:15 pm

Also, M82 & M81 have probably already had a closer encounter
Don’t go spreading rumors!

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Re: APOD: Andromeda Station (2020 Mar 26)

Post by Ann » Thu Mar 26, 2020 7:42 pm

neufer wrote:
Thu Mar 26, 2020 12:06 pm
https://www.goodreads.com/quotes/tag/sherlock-holmes wrote:


“Holmes and Watson are on a camping trip. In the middle of the night Holmes wakes up and gives Dr. Watson a nudge. "Watson" he says, "look up in the sky and tell me what you see."

"I see millions of stars, Holmes," says Watson.

"And what do you conclude from that, Watson?"

Watson thinks for a moment. "Well," he says, "astronomically, it tells me that there are millions of galaxies and potentially billions of planets. Astrologically, I observe that Saturn is in Leo. Horologically, I deduce that the time is approximately a quarter past three. Meterologically, I suspect that we will have a beautiful day tomorrow. Theologically, I see that God is all-powerful, and we are small and insignficant. Uh, what does it tell you, Holmes?"

"Watson, you idiot! Someone has stolen our tent!”

― Thomas Cathcart, Daniel Klein

Wait! Doctor Watson missed one of his lines!

"Calendarily, I can tell that the current month may well be January or February, since Leo is so easily visible at 2.45 a.m. from a latitude probably similar to that of London's. No wonder, therefore, that I feel cold, since these small hours winter nights are so often chilly."

Ann
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johnnydeep
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Re: APOD: Andromeda Station (2020 Mar 26)

Post by johnnydeep » Thu Mar 26, 2020 8:35 pm

neufer wrote:
Thu Mar 26, 2020 4:34 pm
johnnydeep wrote:
Thu Mar 26, 2020 3:12 pm
neufer wrote:
Thu Mar 26, 2020 12:06 pm

"I see millions of stars, Holmes," says Watson.

"And what do you conclude from that, Watson?"

Watson thinks for a moment. "Well," he says, "astronomically, it tells me that there are millions of galaxies and potentially billions of planets.
The entire quote is pretty darn funny, but the nerd in me has a problem with deducing that there are millions of galaxies from seeing millions of stars in the sky. It just doesn't follow.
  • If Watson has good enough eyesight to "see millions of stars" then
    I wouldn't dare question his insight to deduce "that there are millions of galaxies."
https://www.etymonline.com/search?q=galaxy wrote:
<<galaxy (n.) late 14c., from French galaxie or directly from Late Latin galaxias "the Milky Way" as a feature in the night sky (in classical Latin via lactea or circulus lacteus), from Greek galaxias (adj.), in galaxias kyklos, literally "milky circle," from gala (genitive galaktos) "milk."

The technical astronomical sense in reference to the discrete stellar aggregate including the sun and all visible stars emerged by 1848. Figurative sense of "brilliant assembly of persons" is from 1580s. Milky Way is a translation of Latin via lactea.

Originally ours was the only one known. Astronomers began to speculate by mid-19c. that some of the spiral nebulae they could see in telescopes were actually immense and immensely distant structures the size and shape of the Milky Way.>>
I'm only saying that I don't think you can deduce the existence of many galaxies strictly from seeing many stars no matter how many you happen to see. Knowing there are other galaxies requires outside assumptions. However, I could agree that if Watson was seeing the individual stars in Andromeda, which is impossible for the unaided eye (barring a supernova), and if he knew that was indeed a separate galaxy, he could plausibly deduce that it wasn't the only one.

BTW, thanks for your original post: it induced me to buy the book "Plato and a Platypus Walk into a Bar". My dad was a philosophy professor, and he would have gotten a kick out of it, as I presume will I!