NICER’s night moves trace the X-ray sky

NASA/Goddard Space Flight Center

This image of the whole sky shows 22 months of X-ray data recorded by NASA's Neutron star Interior Composition Explorer (NICER) payload aboard the International Space Station during its nighttime slews between targets. Use the slider to identify prominent sources. NICER frequently observes targets best suited to its core mission ("mass-radius" pulsars) and those whose regular pulses are ideal for the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) experiment. One day they could form the basis of a GPS-like system for navigating the solar system. Credit NASA/NICER
This image of the whole sky shows 22 months of X-ray data recorded by NASA’s Neutron star Interior Composition Explorer (NICER) payload aboard the International Space Station during its nighttime slews between targets. Use the slider to identify prominent sources. NICER frequently observes targets best suited to its core mission (“mass-radius” pulsars) and those whose regular pulses are ideal for the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) experiment. One day they could form the basis of a GPS-like system for navigating the solar system. Credit NASA/NICER

In this image, numerous sweeping arcs seem to congregate at various bright regions. You may wonder: What is being shown? Air traffic routes? Information moving around the global internet? Magnetic fields looping across active areas on the Sun?

In fact, this is a map of the entire sky in X-rays recorded by NASA’s Neutron star Interior Composition Explorer (NICER), a payload on the International Space Station. NICER’s primary science goals require that it target and track cosmic sources as the station orbits Earth every 93 minutes. But when the Sun sets and night falls on the orbital outpost, the NICER team keeps its detectors active while the payload slews from one target to another, which can occur up to eight times each orbit.

The map includes data from the first 22 months of NICER’s science operations. Each arc traces X-rays, as well as occasional strikes from energetic particles, captured during NICER’s night moves. The brightness of each point in the image is a result of these contributions as well as the time NICER has spent looking in that direction. A diffuse glow permeates the X-ray sky even far from bright sources.

The prominent arcs form because NICER often follows the same paths between targets. The arcs converge on bright spots representing NICER’s most popular destinations — the locations of important X-ray sources the mission regularly monitors.

“Even with minimal processing, this image reveals the Cygnus Loop, a supernova remnant about 90 light-years across and thought to be 5,000 to 8,000 years old,” said Keith Gendreau, the mission’s principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’re gradually building up a new X-ray image of the whole sky, and it’s possible NICER’s nighttime sweeps will uncover previously unknown sources.”

NICER’s primary mission is to determine the size of dense remains of dead stars called neutron stars — some of which we see as pulsars — to a precision of 5%. These measurements will finally allow physicists to solve the mystery of what form of matter exists in their incredibly compressed cores. Pulsars, rapidly spinning neutron stars that appear to “pulse” bright light, are ideally suited to this “mass-radius” research and are some of NICER’s regular targets.

Other frequently visited pulsars are studied as part of NICER’s Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) experiment, which uses the precise timing of pulsar X-ray pulses to autonomously determine NICER’s position and speed in space. It’s essentially a galactic GPS system. When mature, this technology will enable spacecraft to navigate themselves throughout the solar system — and beyond.


From EurekAlert!

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Joel O'Bryan
June 1, 2019 10:30 pm

Neutron stars are really cool when you think about it. Spinning super fast like an ice skater with her arms pulled in tight.

I mean compare that to black holes… BORE.RING. All that remains in our universe of a onece-bigstar that is now a black hole is gravity and spin. That’s it.
Neutron stars on the other hand… they can make things becasue they still exist in our universe, and then if they are in a binary neutron star configuration, a “BNS” in the parlance, and its really cool in hugely Geek way, like a figure skater pair that you will one day hook-up but on an astronomical level.
And when they (the binary neutrons stars) finally collide in a big smash-up, the “nasty” they give off is ferocious amounts of everything through the entire periodic table in a Rapid-synthesis process of high energy neutrons hitting nuclei, called the R-Process.
The R-process from a storm of neutrons from a shatttered neutron star then splatters neutronium liberated from its gravity confinement to make new stuff.
Neutronium is so dense if you had a match-box piece of it would weigh ~1/2 a gigatonne, and here on Earth it would drive it’s way to the core and oscillate back and forth like a pingpong ball in molassas until it finally came to rest under friction at the center.
The R-process makes super radioactive of mostly rare-earths (and some heavier like uranium) of all neutron counts that decay with furious amounts of energy to make more stable nuclei. This gives off a very predictable (from theory) EM light decay curve.
That was probably how every element around you and in you right now that is heavier than iron was made, in a neutron star smash up 8-5 Billion years ago.

And when these BNS’s finally end their dance and hook-up…. gravitational waves. Not nearly as big GW’s as a binary black hole merger, but much more interesting because there is no event horizon at merger to conceal the electromagnetic signature of the final moments of inspiral. A burst of gamma rays from the BNS tidal smash up/coalescence. An event horizon may form with a few seconds, but by then at least a significant fraction of material is outside the event horizon to announcement the merger, and that cocoon of super hot debris, life-seeding material is moving out at 0.1 to 0.3 c and emitting a furious amount of decay energy.
This is the hot thing in astrophysics today — Chasing BNS smash-ups with telescopes and neutrino detectors after a GW is detected by one of 4 currently operating GW Michaelson interferometers.
Trying to figure out how many there are in a neighborhood of the universe will tell us what kind of neighborhood we live in.

Reply to  Joel O'Bryan
June 2, 2019 1:17 am

The late Steven Hawking wrote in 2014 that there are no black holes, this from the top quantum relativity mentor himself, a master of the maths.
Information Preservation and Weather Forecasting for Black Holes
This serious paper is well worth reading, relatively accessible. The euphemism is a bombshell – looks like he pulled the carpet right out from under them. So not only do they evaporate, but actually do not form either. There are ephemeral event horizons.
And that 4 million mass BH at the Galaxy’s center is producing huge high energy lobes recently observed above and below the plane. So not boring at all.
Einstein was asked about Schwarzschild’s solution, and dismissed it as unphysical as time would stop before collapse allowing no change – not possible physically. He proposed the collapse energy density would be converted to space. No wonder he was looking for a unified theory.

It sure looks like our Sun formed on a super dense neutron remnant of a Supernova, i.e. we live right next to a pulsar.

Reply to  bonbon
June 2, 2019 9:21 am

The problem I have in understanding Black Holes is that the explanation/description only seems to work in two dimensions. How can it be a Black Hole “Disk” when it should be a Black Hole “Sphere?” Or, are they just simplifying the explanation?
Second question: Why is it that when we look at the Universe we see ~13.8 billion light years outward in all (spherical) directions? That would imply that we, the Earth, are at the center of the Universe which should be statistically improbable. Or it implies that the Universe is MUCH larger than ~13.8 light years old and therefore MUCH larger and therefor older.

Reply to  Usurbrain
June 2, 2019 11:58 am

1. Black holes are spheroidal. They must retain their angular momentum, and so might be slightly smaller event horizon at its respective equator. The image of it being a disc is twofold:
First, an accretion disc will form outside of the event horizon from falling matter through conservation of momentum and friction.
Second, a BH will lens light so intensely, that an observer would perceive it something like a disc from all but two directions. Those two are the poles about the accretion disc, which furious blast out gamma rays. As such, an observer would be too busy dying of radiation sickness to care about peculiarities in perception.

2. The prevailing understanding is that the universe is many times larger than what we are capable of observing. There is some reason for this:
First, remember that the speed of light governs our range of viewing. By looking further away, we look further back in time. As such, we can only look as far as the Cosmic Microwave Background (CMB for short). The CMB was formed when the primordial matter and energy cooled down and spread out enough for light to separate from matter. Based on harmonic discrepancies in the CMB, and yes, the speed of light, this event happened about three hundred eighty thousand years after the Big Bang.
Then came a long period of nothing, well long in a human scale. The first stars emerged some two hundred million years after the Big Bang. As such, there really isn’t anything to see beyond the observable universe, well short of having an FTL drive (which is pretty much impossible).

Crispin in Waterloo but really in San Francisco
Reply to  Patrick
June 2, 2019 4:14 pm


That view prevails in certain circles. There are other possibilities including the following.

The universe is unending in extent. There are other types of matter which are unlike the visible kind we prefer. The CMB is old light from far away (from well beyond the “visible horizon” of 13.8 Bn light years.

In support of this view is the inability of visible matter to account for the rotation (or even the formation) of barred spiral galaxies, and the problems remaining even after invoking Dark Matter. There has to be at least one additional type of matter.

Another is the impossibility of space with absolutely nothing in it, which is a supposition of the BB theory. It is an astrophysical view akin to medicine before the discovery of bacteria, then the discovery of viruses, then the discovery of prions. There is a great deal left to find in the universe. Some things are undetectable directly so we must design experiments to detect them indirectly using our minds.

Reply to  Patrick
June 2, 2019 4:28 pm

Thank you for that explanation.
My “education” in this area has been limited to the Discovery and Science channel documentaries.

Reply to  Usurbrain
June 2, 2019 4:30 pm

As I understand it, we are at the centre of the Universe. And so is every other point. All points in the Universe were once one point, then came the Big Bang. Add to this that spacetime is curved. Stand anywhere in the Universe and look far enough out, you will see the back of your head.


D. J. Hawkins
Reply to  JohnB
June 4, 2019 5:15 pm

As it’s been explained to me, we aren’t at the center of a sphere. We’re ON the sphere, and the 13.8 billion l-y limit is the horizon from where we are on the sphere. As the universe (the surface of the sphere we’re on) expands, our horizon “flattens”, allowing us to see further, but really not allowing us to see more proportionally.

Reply to  bonbon
June 3, 2019 2:33 am

quote Hawking:

The absence of event horizons mean that there are no black holes – in the sense of regimesfrom which light can’t escape to infinity. There are however apparent horizons which persist for a period of time.

So the black hole is real in fact, but it is slightly less black than expected, let’s you get out of the hole ‘eventually’, but evidently not in one piece.

Reply to  Joel O'Bryan
June 3, 2019 7:52 am

Agree, Joel. Our heaviest elements including rare earths prb’ly came from neutron star collisions instead of the Type 2 supernovas as previously thought (tho they produce alittle). So neutron stars have had far more influence on us/Earth than black holes.

June 1, 2019 10:39 pm

The prominent arcs form because NICER often follows the same paths between targets.

In other words, the dark areas haven’t been looked at much/at all. yes/no?

Are there background X-rays the same way there are background microwaves? Does the presence/absence/behaviour of X-rays tell us anything about dark matter? link

Reply to  commieBob
June 2, 2019 6:39 am

“…the dark areas haven’t been looked at much/at all. yes/no?”

FYI, the NICER article URL link: [Also, it would have been ‘nicer’ if this URL had been included in the WUWT article].

In the original NICER article you’ll find there is an interactive ‘slider’ which reveals the names of the bright point sources. The arcs merely represent the celestial coordinates where NICER has sampled Xray densities.

Recall that the sensor was installed on the ISS and operated by the astronauts, who could point it in directions of interest. So that’s why the bright points of interest are intersected by many arcs. Because the operators tended to point in those directions.

So a continuous manifold mapping could be estimated by interpolation (Krieging etc) , which would generate a smoothly varying background up to the dozen or ‘hot spot’ singularities.

Hence their comment: “A diffuse glow permeates the X-ray sky even far from bright sources.” So, yes, the dark areas were merely ‘regionss of disinterest’.

For galactic navigation purposes, a solid state imager could generate this manifold more efficiently using a conventional raster scan.

Loren Wilson
Reply to  Johanus
June 2, 2019 3:59 pm

Interpolation is not appropriate if there are point sources and you don’t know their positions. You have to do a tight scan of at least one section of the sky to see what level of scan you can use and find most of the sources. Interpolation only works if there is a smooth field and you have no minima or maxima (or step changes) in the field between measured points. Interpolation can be applied to the earth’s temperature if we had enough stations to show that these conditions are met. We don’t.

J Mac
June 1, 2019 10:56 pm

OK – This is a very unique and cool investigation of galactic x-ray sources. The potential for using it as a solar system navigation reference is a wonderful bonus!

June 2, 2019 1:12 am

How Cosmic-ray Protons Make Gamma rays
In the simplest and most common interaction, a cosmic-ray proton strikes another proton. The protons survive the collision, but their interaction creates an unstable particle — a pion — with only 14 percent the mass of a proton. In 10 millionths of a billionth of a second, the pion decays into a pair of gamma-ray photons. More complex scenarios occur when cosmic-ray protons strike nuclei containing greater numbers of particles.

June 2, 2019 1:13 am

In other words, minus much obfuscation, hype, and discombabulation in the article, this is not a picture of the night sky in X-ray band, it is a picture of the wandering trajectories described by sensors.

June 2, 2019 1:59 am

”… and you can see the CO2 in the bright bits… … I mean, y’know, it’s like, totally amazing!”

June 2, 2019 4:28 am

NASA has released this picture ahead of the big event.
Its explanatory test reads:
Happy Birthday Mr. President,
Happy Birthday to you.
Thank’s Mr. President
For all the things you’ve done
The battles you’ve won
Don’t you know Mr. President
Our science is without precedent
We look night in night out
But our space budget
Is about to run out.
Happy Birthday Mr. President,
Happy Birthday to you.

June 2, 2019 5:42 am

WOW! Some terrific unsettled science in the comments. The “R-Process?” New space being created?

Reply to  pochas94
June 2, 2019 8:25 am
Tom Abbott
June 2, 2019 6:28 am

From the article: “which uses the precise timing of pulsar X-ray pulses to autonomously determine NICER’s position and speed in space. It’s essentially a galactic GPS system. When mature, this technology will enable spacecraft to navigate themselves throughout the solar system — and beyond.”

Gotta love it!

June 2, 2019 7:09 am

Multiple lines of evidence point to one or more moderately nearby supernovae, with the strongest signal at ∼2.6 Ma. We build on previous work to argue for the likelihood of cosmic ray ionization of the atmosphere and electron cascades leading to more frequent lightning and therefore an increase in nitrate deposition and wildfires. The potential exists for a large increase in the prehuman nitrate flux onto the surface, which has previously been argued to lead to CO2 drawdown and cooling of the climate. Evidence for increased wildfires exists in an increase in soot and carbon deposits over the relevant period. The wildfires would have contributed to the transition from forest to savanna in northeast Africa, long argued to have been a factor in the evolution of hominin bipedalism.

June 2, 2019 7:44 am

There is no such thing as a neutron star. Think about it, a free neutron can only last about a little less than 15 minutes. And no, the neutron star is theorized to spin as fast as a dentist’s drill. Speaking of dentists, astronomers think that x-rays can be created by gravity. So, why doesn’t your dentist check your teeth by dropping a hammer nearby? Because x-rays are created by electricity, not gravity. Gravity’s force is weaker than Electrical force by a billion, billion, billion billion times. 10^39 times weaker.

Today’s scientists are science fiction writers. There is no dark matter, no dark energy, no black holes. All fiction. There are perfectly sane explanations in an Electric Universe for all the things these concepts were invented to solve.

Reply to  THX1138
June 2, 2019 8:19 am

Astronomers and solar people don’t believe in electric currents. Only today by addressing a solar scientist here I had to write elaborate explanation how a stream of charged particles whose electric and magnetic fields are linked together into a propagating string along spiralling trajectory, while anywhere else a simple term ‘electric current’ would do.

Reply to  Vuk
June 2, 2019 10:18 am

My contribution to unsettled science is that lines of magnetic force do leave the chromosphere as flux tubes which unwind and transfer their considerable energy to the solar wind, resulting in the anomalously high temperatures observed by satellites close in.

Reply to  pochas94
June 2, 2019 12:32 pm

What I have in mind is a close flux tube (magnetic cloud / rope) generated by a CME, it propagates as far as the outer solar system, whereby its magnetic shock-wave pushes the ordinary solar wind out of its way.
Image credit: NASA Goddard Space Flight Center.
such flux tube is linked to its source for a period of many days and it is wound into Parker spiral
comment image
despite Dr.S’s protestations

June 2, 2019 7:44 am

Hope everyone has read Dragon’s Egg by Robert L. Forward.
Quite a story of what life could be like on a neutron star.

Reply to  Yirgach
June 2, 2019 7:39 pm

Happen to own both that and the sequel (“Starquake”). Although – with them being sold USED for more than $50 on Amazon these days, I may not have them all that long. Ridiculous.

Pamela Gray
June 3, 2019 7:29 am

I am sure this will somehow be connected to something alarming. Oh wait, it already has.

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