Hubble Space Telescope Spots the Farthest Known Star (engadget.com)

Researchers using Hubble space telescope data have spotted Icarus (aka MACS J1149+2223 Lensed Star 1), a blue supergiant whose light was emitted when it was 9 billion light years away from Earth -- over 100 times farther than the previous record-setter. According to Engadget, "They captured the star thanks to a rare, ideal gravitational lensing effect where the star's light was magnified not only by the gravity of an in-between galaxy cluster 5 billion light years from Earth, but by a star inside that cluster." From the report: Observers had been keeping close watch on the cluster since 2014, when they'd detected a supernova that turned out to be present in a galaxy 9 billion light years away. They realized Icarus was present in April 2016, when a point of light near the supernova seemed to change brightness. Don't get too attached to this new discovery. With this kind of distance, Icarus has long-since turned into a neutron star or black hole. The findings are still advancing science in ways you might not expect, however. As the Guardian noted, the Icarus study ruled out a theory that dark matter consists of black holes. If that had been the case, they would have brightened Icarus even more. And if nothing else, this proves that humanity can detect more than just the largest and brightest celestial objects at these kinds of distances.

Comments

The Hubble saw _THAT_?!

[Pezbian]

If that old thing can see something so unique and far away, I can only imagine what the James Webb Space Telescope is ultimately capable of.

If it ever launches.

Re:The Hubble saw _THAT_?!

[Gavagai80]

The Hubble isn't the telescope doing 99% of the magnification work here. The galaxy cluster and the star within are the two powerful telescopes being used.

Re:The Hubble saw _THAT_?!

[jfdavis668]

They use the light of type Ia supernovas, which explode with a know brightness, to determine the distance to a galaxy. Then they compare that to its redshift so determine the redshift to distance ratio. Then, all you need to do is measure the object's redshift to determine its distance.

Re:The Hubble saw _THAT_?!

[stevelinton]

If that old thing can see something so unique and far away

I still don't understand how they can determine distances of such far-out objects. Yes I am aware of standard candles, and that we "know" how far away they are based on observed brightness. But observed brightness isn't just impacted by distance, it is also impacted by the size of the object. So how can we be so sure that these standard candles are not bigger or smaller than we assume they are?

Are the distances simply so large, that a standard candle would need to be exponentially larger/smaller than our assumed size in order to significantly impact the calculated distance?

Standard candles are things that have a fixed total brightness (or at least a brightness that we can work out independent of their size).

For instance a certain type of supernova is believed to happen when a white dwarf star, slowly accreting matter from a companion, finally gets too massive to support itself and collapses into a neutron star. Regardless of the mass of the original white dwarf, this mass at which this collapse happens is pretty much the same, and so the total brightness of this type of supernova is more or less constant.

Re:No grav lensing

[jfdavis668]

Space is bent by gravity, not light. Light then takes the shortest path through the curved space time.

Re:No grav lensing

[paradigmsareconstruc]

It's curious to watch people pretending today like there is only one way to bend starlight. The current craze over gravitational lensing actually began with a panic by mainstream astronomers ...

Seeing Red: Redshifts, Cosmology and Academic Science
Halton Arp

"Prior to the 1950's Fritz Zwicky, the Swiss astronomer who had an illustrious and turbulent career in California, was aware that strong gravitational fields had been shown to bend light rays -- as in the famous eclipse observations of the displacement of positions of stars observed at a grazing angle to the sun's limb. At that time he started looking for an extragalactic object which might be directly behind another, and thus have its outer light rays bent inward by the gravitational field of the foreground object so that it formed a ring or halo. Some 'ring galaxies' were found, but they all seemed to be physical rings around the galaxy and not magnified background objects.

The more common situation to be expected was when the background object was not exactly centered and the gravitational ring collapsed into a one sided arc. But no striking examples of that were found either, so the subject had gone dormant. The sudden revival of gravitational lensing to the huge industry it is today is simply due to the quasars. In the 1960's and 70's I started finding high densities of quasars concentrated around nearby, low-redshift galaxies. Because of their high redshifts, it was felt that they could not be associated with low-redshift galaxies ...

The Einstein Cross ...

... When it was first discovered it caused a panic because it was essentially a high redshift quasar in the nucleus of a low redshift galaxy ... Gravitational galaxy lensing had to be invoked for this one ...

'We put the slit of the spectrograph between quasars A and B in the Einstein Cross and we registered a broad Lyman alpha emission in each quasar. But between them we found a narrow Lyman alpha line -- it looks like there is some low density gas at the same redshift as the quasars between them.' A jolt ran through me and I looked at him to try to read the expression on his face. As usual in such situations, his eyes avoided mine. The point was, of course, that a line between quasar A and B passed directly between the nucleus of the galaxy and quasar D. On the face of it high redshift gas was indicated near the nucleus of the low redshift galaxy. But what I knew, and what anyone can know looking at the Lyman alpha centered photograph in Color Plate 7-7, is that there is a putative Lyman alpha filament connecting quasar D to the galaxy nucleus. What the spectrum had confirmed was that this indeed was a low density, excited hydrogen filament connecting the two objects of vastly different redshift."

If you actually review discussions of the original observation, it's very clear that the astronomers were not considering any alternative hypotheses ...

The Impact of Gravitating Lensing on Astrophysics, Martin J. Rees Institute of Astronomy, Madingley Road, Cambridge, CB3 OHA

"All that can be said in rebuttal is that it would be even more remarkable if the 4 images, all with the same redshift, existed for some other reason, in a configuration which can be so well modelled by the lensing hypothesis"

The problem, of course, is that Halton Arp -- Edwin Hubble's protege -- very much was able to produce an alternative hypothesis (based upon ejection from active galactic nuclei), and once he suggested it in a published work, he was removed from his telescope time.

The following quote seems to reveal the secret sauce of micro-lensing:

Gravitational Lensing: An Astrophysical Tool

"1.3 Models

The small number of observables in lensing means that the observat

Re:No grav lensing

[paradigmsareconstruc]

Halton Arp was hardly a "crackpot". He was Edwin Hubble's protege, and both Arp and Hubble were together skeptical of the now-accepted interpretation for redshift. The mainstream moved ahead with that interpretation regardless.

Up to the point where Arp published his paper demonstrating that the assumption that redshift must have only one interpretation was wrong (of course removing the most important argument for the Big Bang), he was considered the world's leading authority on disrupted galaxies. In fact, those galaxies are still labeled by their "Arp number" to this day.

Once he started pitching the argument that galaxies also have an intrinsic redshift value which from observations appears to derive from their age, he was removed from his telescope time. This was actually part of a much larger historical context where Caltech seized the Palomar telescope which was up to that point jointly operated with the Carnegie Foundation. Once they took control of that machine, they made sure that only research which supported the Big Bang hypothesis could be done on it ...

Seeing Red: Redshifts, Cosmology and Academic Science
Halton Arp

"In the 1940's the largest telescope of its time, the 200-inch at Palomar, was conceived and built. Since Rockefeller and Carnegie were rival capitalists the Rockefeller Foundation could only give the money to California Institute of Technology rather than the Carnegie Institution of Washington where the world's leading astronomers were. Cal Tech, however had no Astronomy Department so an agreement was signed between the two Institutions that they would jointly operate the Observatory. The noted Carnegie astronomers such as Hubble, Baade, R. Minkowski then initially used most of the telescope time. Younger staff members were gradually included ...

Quasars were discovered in 1963 and astronomers rushed to observe them because they assumed their high redshifts meant they were at great distances and that the nature of the universe would thereby be revealed. The Cal Tech radio astronomer who isolated the positions of the first quasars asked for telescope time to observe their spectra and obtain their redshifts. He was told only certain of the faculty could observe with the 200-inch telescope. Those select few went on to measure the spectra and reap the headlines and the original discoverer left the field in disgust ...

There followed an interregnum of about 17 years in which the Cal Tech astronomy Department pressed for a larger and larger share of the telescope time. One must know that in the operating agreement for the Observatory that the Carnegie astronomers were appointed full faculty members at Cal Tech. Then in 1980 Cal Tech broke the agreement, taking over the 200-inch and severing the faculty appointments of the Carnegie astronomers. There were bitter protests by the suddenly discharged faculty (Appeals to the American Association of University Professors were not heeded) ..."

You might consider looking more carefully at the actual history for how we've arrived at this conclusion of a Big Bang.