Starship Asterisk*

by **neufer** » Thu Apr 12, 2018 5:43 pm

Click to play embedded YouTube video.

Berder wrote: ↑Thu Apr 12, 2018 12:49 pm
Tszabeau wrote: ↑Wed Apr 11, 2018 11:54 am
If this is not a nova... why can we see the star but not the galaxy that it is in or, are my eyes just failing?
Think of it as a really strong magnifying glass panning over an object. You only see a tiny volume that's in focus. Space is mostly empty, even in galaxies, so the chances of having a star in the path at the right distance are very slim. We should just keep watching that spot, maybe it will pass over a galactic center or globular cluster, that would be spectacular.

by **Justamaybe** » Thu Apr 12, 2018 5:30 pm

Chris Peterson wrote: ↑Thu Apr 12, 2018 5:04 pm
Justamaybe wrote: ↑Thu Apr 12, 2018 4:57 pm
Chris Peterson wrote: ↑Wed Apr 11, 2018 5:09 pm

There is no such thing as proof in science. It isn't something that scientists look for.
AHA!!! So the world JUST A MAY BE FLAT!!!!!!!!! (I speaka asa an Italiano.)
The shape of the world isn't a scientific theory, but a scientific observation. We may misinterpret observations, of course, although I think the conclusion we arrive at when observing the shape of the Earth is reasonably solid.

So you trust in someone else's observations. Someone else's images. Okay. But I saw it for myself .. my spirit was lifted out of my sleep to someplace between the earth and moon .. I was turned around, and saw the earth as a near-sphere. That's how I know it's not flat. Though you can't explain my experience through science, it is direct, personal proof.

by **Chris Peterson** » Thu Apr 12, 2018 5:04 pm

Justamaybe wrote: ↑Thu Apr 12, 2018 4:57 pm
Chris Peterson wrote: ↑Wed Apr 11, 2018 5:09 pm
Justamaybe wrote: ↑Wed Apr 11, 2018 5:04 pm Why all the excitement? "Was this flash the farthest star yet seen? An unexpected flash of light noticed fortuitously on Hubble Space Telescope images may prove to be not only ..."

It's all just a possibility right now .. but the way things go, by tomorrow the weight of opinion will prevail and the 'maybe' will have been removed .. while the proof is yet to be spoken of.
There is no such thing as proof in science. It isn't something that scientists look for.
AHA!!! So the world JUST A MAY BE FLAT!!!!!!!!! (I speaka asa an Italiano.)

The shape of the world isn't a scientific theory, but a scientific observation. We may misinterpret observations, of course, although I think the conclusion we arrive at when observing the shape of the Earth is reasonably solid.

by **Justamaybe** » Thu Apr 12, 2018 4:57 pm

Chris Peterson wrote: ↑Wed Apr 11, 2018 5:09 pm
Justamaybe wrote: ↑Wed Apr 11, 2018 5:04 pm Why all the excitement? "Was this flash the farthest star yet seen? An unexpected flash of light noticed fortuitously on Hubble Space Telescope images may prove to be not only ..."

It's all just a possibility right now .. but the way things go, by tomorrow the weight of opinion will prevail and the 'maybe' will have been removed .. while the proof is yet to be spoken of.
There is no such thing as proof in science. It isn't something that scientists look for.

AHA!!! So the world JUST A MAY BE FLAT!!!!!!!!! (I speaka asa an Italiano.)

by **Berder** » Thu Apr 12, 2018 12:49 pm

Tszabeau wrote: ↑Wed Apr 11, 2018 11:54 am If this is not a nova... why can we see the star but not the galaxy that it is in or, are my eyes just failing?

Think of it as a really strong magnifying glass panning over an object. You only see a tiny volume that's in focus. Space is mostly empty, even in galaxies, so the chances of having a star in the path at the right distance are very slim. We should just keep watching that spot, maybe it will pass over a galactic center or globular cluster, that would be spectacular.

by **Ann** » Thu Apr 12, 2018 9:41 am

rj rl wrote: ↑Thu Apr 12, 2018 7:55 am
Tszabeau wrote: ↑Wed Apr 11, 2018 11:54 am If this is not a nova... why can we see the star but not the galaxy that it is in or, are my eyes just failing?
I too have this question. How come one particular star was magnified?

The way I understand it, this was a case of "microlensing". The particular star was aligned, for a very short time, with a small mass concentration in the foreground. (Or rather, the star, the lensing mass concentration and the Earth were briefly lined up.) If a new picture was taken of this area, the star would probably not be seen, because the alignment of the star, the lensing object and the Earth would not be good enough any more. The line of sight between the Earth, the lensing mass concentration and the faraway star would be "broken".

Why wasn't the rest of the galaxy seen, although this particular star was "lensed into Hubble visibility"? Probably because the lensing object was too small to lens anything but the star in question, or because the star, Icarus, was by far the brightest object in its own vicinity. There might have been other stars nearby, but they may have been too faint to show up, even though they were lensed.

The lensed star could be a runaway star, so that there were no other bright stars around it.

Ann

by **rj rl** » Thu Apr 12, 2018 7:55 am

Tszabeau wrote: ↑Wed Apr 11, 2018 11:54 am If this is not a nova... why can we see the star but not the galaxy that it is in or, are my eyes just failing?

I too have this question. How come one particular star was magnified?

by **moontrail** » Thu Apr 12, 2018 7:46 am

Chris Peterson wrote: ↑Wed Apr 11, 2018 5:38 pm
JohnD wrote: ↑Wed Apr 11, 2018 5:31 pm Neufer calculates that this star is (was?) 14.523 Gigalight years away.
It is 14.5 Gly distant.
It was 5.8 Gly distant from our point in space when the currently observed light was produced.
It took that light 9.5 Gyr to travel between the two points, because the Universe was expanding between them.

What's the range in estimates of the Age of the Universe? About 14 Billion years?
13.8±0.02 Gyr is the most used value. But the value does depend upon the model under consideration.

So, it happened 9.5 Gyr ago (in our point in space relative time).

by **alter-ego** » Thu Apr 12, 2018 5:35 am

neufer wrote: ↑Thu Apr 12, 2018 5:17 am
alter-ego wrote: ↑Thu Apr 12, 2018 5:01 am
Chris Peterson wrote: ↑Wed Apr 11, 2018 5:38 pm ...
It was 5.8 Gly distant from our point in space when the currently observed light was produced.
...
That's right, and assuming a long lived star (not if it's a blue super giant), the star's redshift from our position in space was ~2.3 when the currently observed light was emitted.

You want to try rephrasing that

An observer in our galaxy when the Universe was ~4.3Gyr old, would measure that star's redshift to be ~2.3. (As seen today at z = 1.5, 4.3Gyr was when light from that star was emitted.)

by **neufer** » Thu Apr 12, 2018 5:17 am

alter-ego wrote: ↑Thu Apr 12, 2018 5:01 am
Chris Peterson wrote: ↑Wed Apr 11, 2018 5:38 pm ...
It was 5.8 Gly distant from our point in space when the currently observed light was produced.
...
That's right, and assuming a long lived star (not if it's a blue super giant), the star's redshift from our position in space was ~2.3 when the currently observed light was emitted.

You want to try rephrasing that

by **alter-ego** » Thu Apr 12, 2018 5:01 am

Chris Peterson wrote: ↑Wed Apr 11, 2018 5:38 pm ...
It was 5.8 Gly distant from our point in space when the currently observed light was produced.
...

That's right, and assuming a long lived star (not if it's a blue super giant), the star's redshift from our position in space was ~2.3 when the currently observed light was emitted.

by **neufer** » Thu Apr 12, 2018 1:46 am

Craig Willford wrote: ↑Thu Apr 12, 2018 12:15 am
I am just staggered that they can get a spectrum from such a tiny dot of light in a field full of sources of light AND with undoubtedly such a miniscule AMOUNT of light!

Does Hubble have variable sized masks to allow only the selected source of light through to a spectroscope?

Whatever the mask used at least it can be used twice and then
a subtraction applied thanks to the temporary nature of the source.

by **Craig Willford** » Thu Apr 12, 2018 12:15 am

I am just staggered that they can get a spectrum from such a tiny dot of light in a field full of sources of light AND with undoubtedly such a miniscule AMOUNT of light!

Does Hubble have variable sized masks to allow only the selected source of light through to a spectroscope?

Astronomy sure has advanced since I was a kid! Wow.

by **neufer** » Thu Apr 12, 2018 12:12 am

ta152h0 wrote: ↑Wed Apr 11, 2018 10:28 pm
Was this a " lucky shot " ?

A Fortuitous Flash Photobomb for the Farthest Star.

by **ta152h0** » Wed Apr 11, 2018 10:28 pm

Was this a " lucky shot " ?

by **RJN** » Wed Apr 11, 2018 7:00 pm

moontrail wrote: ↑Wed Apr 11, 2018 10:58 am In the explanation given I miss the info about how far it`s supossed to be.

The word redshift is linked. Please follow the link get the distance in other units! I see this type of hyperlink one of the main utilities of hypertext writing in general -- by linking a word, the hypertext-writer has less of a need to explain that word and can exercise better brevity.

- RJN

by **Chris Peterson** » Wed Apr 11, 2018 5:38 pm

JohnD wrote: ↑Wed Apr 11, 2018 5:31 pm Neufer calculates that this star is (was?) 14.523 Gigalight years away.

It is 14.5 Gly distant.
It was 5.8 Gly distant from our point in space when the currently observed light was produced.
It took that light 9.5 Gyr to travel between the two points, because the Universe was expanding between them.

What's the range in estimates of the Age of the Universe? About 14 Billion years?

13.8±0.02 Gyr is the most used value. But the value does depend upon the model under consideration.

by **JohnD** » Wed Apr 11, 2018 5:31 pm

Neufer calculates that this star is (was?) 14.523 Gigalight years away.
What's the range in estimates of the Age of the Universe? About 14 Billion years?

But the First Stars are said to have shone when it was about 100 million years old, ), 0.1 of a Billion, but we were tod those had been seen ten years ago. What makes this earlier?

JOhn

PS in the time I took to write that, neufer posted again - and this site asked me if I wnated to review my draft post in the elight of his! WHAT a good idea! Full marks, Asterisk!
PPS your embedded video didn't run, neufer, so I've let my post run.

by **neufer** » Wed Apr 11, 2018 5:25 pm

Click to play embedded YouTube video.

Chris Peterson wrote: ↑Wed Apr 11, 2018 5:09 pm
Justamaybe wrote: ↑Wed Apr 11, 2018 5:04 pm
Why all the excitement? "Was this flash the farthest star yet seen? An unexpected flash of light noticed fortuitously on Hubble Space Telescope images may prove to be not only ..."

It's all just a possibility right now .. but the way things go, by tomorrow the weight of opinion will prevail and the 'maybe' will have been removed .. while the proof is yet to be spoken of.
There is no such thing as proof in science.

It isn't something that scientists look for.

by **Chris Peterson** » Wed Apr 11, 2018 5:09 pm

Justamaybe wrote: ↑Wed Apr 11, 2018 5:04 pm Why all the excitement? "Was this flash the farthest star yet seen? An unexpected flash of light noticed fortuitously on Hubble Space Telescope images may prove to be not only ..."

It's all just a possibility right now .. but the way things go, by tomorrow the weight of opinion will prevail and the 'maybe' will have been removed .. while the proof is yet to be spoken of.

There is no such thing as proof in science. It isn't something that scientists look for.

by **Justamaybe** » Wed Apr 11, 2018 5:04 pm

Why all the excitement? "Was this flash the farthest star yet seen? An unexpected flash of light noticed fortuitously on Hubble Space Telescope images may prove to be not only ..."

It's all just a possibility right now .. but the way things go, by tomorrow the weight of opinion will prevail and the 'maybe' will have been removed .. while the proof is yet to be spoken of.

by **bystander** » Wed Apr 11, 2018 4:38 pm

Sa Ji Tario wrote: ↑Wed Apr 11, 2018 1:09 pm Look at the link "... gravitational lens aligned ..." and the same image appears, commenting on another topic

APOD Robot wrote: ↑Wed Apr 11, 2018 4:06 am ... aligned gravitational lenses ...

This link is to the multiple images of the supernova Refsdal (see discussions here and here) lensed by the same galaxy cluster, MACS J1149+2223. That image is from 2015. Later subsequent appearances of Refsdal were predicted and imaged, also in 2015. Icarus was discovered in an image from 2016.

bystander wrote: ↑Wed Apr 11, 2018 4:57 am viewtopic.php?t=38156

by **neufer** » Wed Apr 11, 2018 2:42 pm

hamilton1 wrote: ↑Wed Apr 11, 2018 11:20 am
moontrail wrote: ↑Wed Apr 11, 2018 10:58 am
In the explanation given I miss the info about how far it`s supossed to be.
9 billion light years, I believe.

http://www.astro.ucla.edu/%7Ewright/CosmoCalc.html wrote:
For H_o = 67.74 [from Planck] , Omega_vacuum = 0.683, Omega_Matter = 0.317, z = 1.500

It is now 13.698 Gyr since the Big Bang.
The age at redshift z = 1.5 was 4.226 Gyr.
The light travel time was 9.472 Gyr.
The comoving radial distance, is 14.523 Gly.

Ann wrote: ↑Wed Apr 11, 2018 11:27 am
Futurism wrote:

The star, MACS J1149+2223 Lensed Star 1 (more simply known as “Icarus”) was about 9 billion light years away when it emitted the light now reaching Earth.

Well...not exactly:

The current comoving distance between the Earth and the remains of Icarus is 14.523 Gly..

But the Universe has expanded (1+z) = 2.5 times since Icarus emitted the light we currently see.

Hence, when Icarus emitted that light it was 5.8 Gly (=14.523 Gly/2.5) away from the Milky Way.

Futurism also wrote:

<<The universe is way, way bigger than you can probably comprehend. And because of this astronomical (sorry) size, it can take a really long time for light to reach Earth from the cosmic wilderness. Even traveling at its immense speeds, by the time light from this distant star reached Earth, 9 billion years had passed. When Icarus released the photons currently hitting the Hubble’s cameras, Earth hadn’t even formed yet — it would be another 4.4 billion years before our solar system even began to coalesce from the dust of the universe. Such distant views of the universe are helping astronomers learn about what the universe was like before our time, even giving us glimpses back to the moments after the Big Bang.>>

by **Sa Ji Tario** » Wed Apr 11, 2018 1:09 pm

Look at the link "... gravitational lens aligned ..." and the same image appears, commenting on another topic

by **Tszabeau** » Wed Apr 11, 2018 11:54 am

If this is not a nova... why can we see the star but not the galaxy that it is in or, are my eyes just failing?

Starship Asterisk*

APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Post a reply

Expand view Topic review: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)

Re: APOD: Fortuitous Flash Candidate for the... (2018 Apr 11)