This week’s report on activities aboard the Int. Space Station:
Video: Space to Ground – ISS update – Oct.10.14
This week’s report on activities aboard the Int. Space Station:
Monthly Archives: October 2014
NuSTAR space observatory detects brightest pulsar ever
NASA held a teleconference on Wednesday to announce new findings from the Nuclear Spectroscopic Telescope Array (NuSTAR) mission.
The results describe an unusual source of X-rays that will leave theorists scratching their heads, but also will help astronomers learn more about how black holes and galaxies are formed.
Participants in the teleconference are:
- Paul Hertz, director of astrophysics division, NASA Headquarters, Washington
- Fiona Harrison, NuSTAR principal investigator, California Institute of Technology, Pasadena
- Matteo Bachetti, astronomer, University of Toulouse, France
- Jeanette Gladstone, astronomer, University of Alberta, Canada
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NASA’s NuSTAR Telescope Discovers Shockingly Bright Dead Star
Astronomers have found a pulsating, dead star beaming with the energy of about 10 million suns. This is the brightest pulsar – a dense stellar remnant left over from a supernova explosion – ever recorded. The discovery was made with NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR.
“You might think of this pulsar as the ‘Mighty Mouse’ of stellar remnants,” said Fiona Harrison, the NuSTAR principal investigator at the California Institute of Technology in Pasadena. “It has all the power of a black hole, but with much less mass.”
The discovery appears in a new report in the Thursday, Oct. 9, issue of the journal Nature.
The surprising find is helping astronomers better understand mysterious sources of blinding X-rays, called ultraluminous X-ray sources (ULXs). Until now, all ULXs were thought to be black holes. The new data from NuSTAR show at least one ULX, about 12 million light-years away in the galaxy Messier 82 (M82), is actually a pulsar.
“The pulsar appears to be eating the equivalent of a black hole diet,” said Harrison. “This result will help us understand how black holes gorge and grow so quickly, which is an important event in the formation of galaxies and structures in the universe.”
ULXs are generally thought to be black holes feeding off companion stars — a process called accretion. They also are suspected to be the long-sought-after “medium-size” black holes – missing links between smaller, stellar-size black holes and the gargantuan ones that dominate the hearts of most galaxies. But research into the true nature of ULXs continues toward more definitive answers.
NuSTAR did not initially set out to study the two ULXs in M82. Astronomers had been observing a recent supernova in the galaxy when they serendipitously noticed pulses of bright X-rays coming from the ULX known as M82 X-2. Black holes do not pulse, but pulsars do.
Pulsars belong to a class of stars called neutron stars. Like black holes, neutron stars are the burnt-out cores of exploded stars, but puny in mass by comparison. Pulsars send out beams of radiation ranging from radio waves to ultra-high-energy gamma rays. As the star spins, these beams intercept Earth like lighthouse beacons, producing a pulsed signal.
“We took it for granted that the powerful ULXs must be massive black holes,” said lead study author Matteo Bachetti, of the University of Toulouse in France. “When we first saw the pulsations in the data, we thought they must be from another source.”
NASA’s Chandra X-ray Observatory and Swift satellite also have monitored M82 to study the same supernova, and confirmed the intense X-rays of M82 X-2 were coming from a pulsar.
“Having a diverse array of telescopes in space means that they can help each other out,” said Paul Hertz, director of NASA’s astrophysics division in Washington. “When one telescope makes a discovery, others with complementary capabilities can be called in to investigate it at different wavelengths.”
The key to NuSTAR’s discovery was its sensitivity to high-energy X-rays, as well as its ability to precisely measure the timing of the signals, which allowed astronomers to measure a pulse rate of 1.37 seconds. They also measured its energy output at the equivalent of 10 million suns, or 10 times more than that observed from other X-ray pulsars. This is a big punch for something about the mass of our sun and the size of Pasadena.
How is this puny, dead star radiating so fiercely? Astronomers are not sure, but they say it is likely due to a lavish feast of the cosmic kind. As is the case with black holes, the gravity of a neutron star can pull matter off companion stars. As the matter is dragged onto the neutron star, it heats up and glows with X-rays. If the pulsar is indeed feeding off surrounding matter, it is doing so at such an extreme rate as to have theorists scratching their heads.
Astronomers are planning follow-up observations with NASA’s NuSTAR, Swift and Chandra spacecraft to find an explanation for the pulsar’s bizarre behavior. The NuSTAR team also will look at more ULXs, meaning they could turn up more pulsars. At this point, it is not clear whether M82 X-2 is an oddball or whether more ULXs beat with the pulse of dead stars. NuSTAR, a relatively small telescope, has thrown a big loop into the mystery of black holes.
“In the news recently, we have seen that another source of unusually bright X-rays in the M82 galaxy seems to be a medium-sized black hole,” said astronomer Jeanette Gladstone of the University of Alberta, Canada, who is not affiliated with the study. “Now, we find that the second source of bright X-rays in M82 isn’t a black hole at all. This is going to challenge theorists and pave the way for a new understanding of the diversity of these fascinating objects.”
More about that “bleak” Mars One simulation
I pointed earlier to an MIT student project that simulated a base on Mars similar to that proposed by the Mars One organization. (See the Mars simulation paper (pdf)). Mars One chief Bas Lansdorp responds in the comments to this post: MIT Analysis Paints Bleak Outcome for Mars One Concept – SpacePolicyOnline.com .
Stewart Money also considers the “bleak” description as overly pessimistic: The Mars One Plan: Bleak? or Needs to be Tweeked? – Innerspace.net
There is no doubt that Mars One is risky concept, and if it is to ever gain real traction, it will have to endure a lot more scrutiny than presented in the MIT study. It should probably begin with a clear statement that Mars One is meant as an evolving concept, in which the final product may differ considerable from what has initially been put forward on a time frame which like all space projects, is subject to change. At the same time, its many critics might want to at least consider how much of the risk to any future Mars mission, whether one way of with a return ticket, could be reduced through advancing the Technological Readiness Level (TRL) of some of the core technologies the MIT team identifies.
Finally, they might want to ask why the U.S. is committed to a very different, but perhaps even more financially implausible plan.
The weather on Neptune-sized HAT-P-11b exoplanet + Weathermap of exoplanet WASP-43b
John Batchelor and David Livingston spoke yesterday with Dr. Heather Knutson about Exoplanet HAT-P-11b: The John Batchelor Show Hotel Mars, Wednesday, 10-8-14 – Thespaceshow’s Blog
The exoplanet has been found to have
clear skies and water vapor in its atmosphere. Dr. Knutson explained how clear skies and atmospheric water vapor [were] confirmed, what it means for this specific Neptune size exoplanet and what it means for our planet searches in general. We talked about it having a hot atmosphere, a core but not a solid surface. The exoplanet is not habitable. HAT-P-11b is 120 light years from Earth. Dr. Knutson also explained why so many exoplanets have a cloudy atmosphere and why that limits our research into the exoplanet.
Listen to the show:
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And here is an announcement today from the ESA Hubble Telescope group about measurements of the atmosphere of another exoplanet:
Hubble reveals most detailed exoplanet weather map ever
A team of scientists using the NASA/ESA Hubble Space Telescope have made the most detailed map ever of the temperature of an exoplanet’s atmosphere, and traced the amount of water it contains. The planet targeted for both of the investigations was the hot-Jupiter exoplanet WASP-43b.
WASP-43b is a planet the size of Jupiter but with double the mass and an orbit much closer to its parent star than any planet in the Solar System. It has one of the shortest years ever measured for an exoplanet of its size — lasting just 19 hours.
A team of astronomers working on two companion studies have now created detailed weather maps of WASP-43b. One study mapped the temperature at different layers in the planet’s atmosphere, and the other traced the amount and distribution of water vapour within it — detail is shown in the video created by the team.
“Our observations are the first of their kind in terms of providing a two-dimensional map of the planet’s thermal structure,” said Kevin Stevenson from University of Chicago, USA, lead author of the thermal map study. “These maps can be used to constrain circulation models that predict how heat is transported from an exoplanet’s hot day side to its cool night side.”
The planet has different sides for day and night because it is tidally locked, meaning that it keeps one hemisphere facing the star, just as the Moon keeps one face toward Earth. The Hubble observations show that the exoplanet has winds that howl at thespeed of sound from a day side that is hot enough to melt iron — soaring above 1500 degrees Celsius — to the pitch-black night side that sees temperatures plunge to a comparatively cool 500 degrees Celsius.
To study the atmosphere of WASP-43b the team combined two previous methods of analysing exoplanets for the first time.
By looking at how the parent star’s light filtered through the planet’s atmosphere — a technique called transmission spectroscopy — they determined the water abundance of the atmosphere on the boundary between the day and night hemispheres.
In order to make the map more detailed the team also measured the water abundances and temperatures at different longitudes. To do this they took advantage of the precision and stability of Hubble’s instruments to subtract more than 99.95% of the light from the parent star, allowing them to study the light coming from the planet itself — a technique called emission spectroscopy. By doing this at different points of the planet’s orbit around the parent star they could map the atmosphere across its longitude.
In this artist’s illustration the Jupiter-sized planet WASP-43b orbits its parent star in one of the closest orbits ever measured for an exoplanet of its size — with a year lasting just 19 hours.
The planet is tidally locked, meaning it keeps one hemisphere facing the star, just as the Moon keeps one face toward Earth.
The colour scale on the planet represents the temperature across its atmosphere. This is based on data from a recent study that mapped the temperature of WASP-43b in more detail than has been done for any other exoplanet.
“We have been able to observe three complete rotations — three years for this distant planet — during a span of just four days,” explained Jacob Bean from the University of Chicago, USA, leader of the research project. “This was essential in allowing us to create the first full temperature map for an exoplanet and to probe its atmosphere to find out which elements it held and where.”
Finding the proportions of the different elements in planetary atmospheres provides vital clues to understanding how planets formed.
“Because there’s no planet with these tortured conditions in the Solar System, characterising the atmosphere of such a bizarre world provides a unique laboratory with which to acquire a better understanding of planet formation and planetary physics,” said Nikku Madhusudhan of Cambridge University, UK, co-author of both studies. “In this case the discovery fits well with pre-existing models of how such planets behave.”
The team found that WASP-43b reflected very little of its host star’s light. An atmosphere like that on Earth, with clouds that reflect most of the sunlight, is not present on WASP-43b, but the team did find water vapour in the planet’s atmosphere.
“The planet is so hot that all the water in its atmosphere is vapourised, rather than condensed into the icy clouds we find on Jupiter,” said team member Laura Kreidberg of the University of Chicago, lead author of the study mapping water on the planet. Kreidberg describes both results in her online video.
Water is thought to play an important role in the formation of giant planets. Astronomers theorise that comet-like bodies bombard young planets, delivering most of the water and other molecules that we observe. However, the water abundances in the giant planets of the Solar System are poorly known because water is locked away as ice, deep in their atmospheres which makes it difficult to identify.
“Space probes have not been able to penetrate deep enough into Jupiter’s atmosphere to obtain a clear measurement of its water abundance. But this giant planet is different,” added Derek Homeier of the École Normale Supérieure de Lyon, France, co-author of the studies. “WASP-43b’s water is in the form of a vapour that can be much more easily traced. So we could not only find it, we were able to directly measure how much there is and test for variations along the planet’s longitude.”
In WASP-43b the team found the same amount of water as we would expect for an object with the same chemical composition as the Sun.
“This tells us something fundamental about how the planet formed,” added Kreidberg.“Next, we aim to make water-abundance measurements for different planets to explore their chemical abundances and learn more about how planets of different sizes and types come to form around our own Sun and the stars beyond it.” [1]
The results are presented in two new papers, one on the thermal mapping of the planet’s atmosphere — published online in Science Express on 9 October — and the other on mapping the water content of the atmosphere — published in The Astrophysical Journal Letters on 12 September 2014.
Sci-Tech: Report on an extended study of Rossi LENR reactor confirms high energy output
An extended study of a Rossi type reactor device (see posts here and here) has been carried out by a team of Italian and Swedish researchers. The results again shows high energy output for which a nuclear reaction is the only explanation.
Mats Lewan, who has written extensively about the Rossi story for the technical magazine Ny Teknik, writes about the new paper: New scientific report on the E-Cat shows excess heat and nuclear process – An Impossible Invention
In order to avoid doubts that were presented with regard to their earlier report, several things have been changed: The measurement was performed during 32 days in a neutral laboratory in Switzerland, electric measurement on the input power has been improved, a 23-hour test of the reactor without charge was done in order to calibrate the measurement set-up, and chemical analysis of the fuel before and after the run has been performed with five different methods.
He includes some comments from one of the authors, Professor Bo Höistad of Uppsala University:
Mats: What have you done differently this time, based on the experiences from your last measurement and report?
Höistad: An accurate measurement, particularly the control of energy balance without fuel in the reactor, and a isotopic analysis of the fuel.
Mats: What reactions do you expect on the report?
Höistad: Hopefully that the interest in the possibility of achieving LENR reactors get a decent boost, and that critical overtones in the debate are downplayed in favor of scientific discussions.
Mats: What do you personally feel facing the inexplicable observations you have made?
Höistad: As pointed out in our paper, we face a phenomenon without explanation. However, we can not categorically reject the clear experimental results just because a credible theory is currently lacking. We need to relate to the actual experimental results and continue the investigations to gain more knowledge about the LENR phenomenon.
The paper has been submitted to Physics Review D and was available on the preprint site arXiv.org but was removed, no doubt because of the usual controversy that surrounds any cold fusion type paper. The report, however, is available on line:
Observation of abundant heat production from a reactor device and of isotopic changes in the fuel (pdf)
Giuseppe Levi – Bologna University, Bologna, Italy
Evelyn Foschi – Bologna, Italy
Bo Höistad, Roland Pettersson and Lars Tegnér – Uppsala University, Uppsala, Sweden
Hanno Essén – Royal Institute of Technology, Stockholm, Sweden
Abstract:
New results are presented from an extended experimental investigation of anomalous heat production in a special type of reactor tube operating at high temperatures. The reactor, named E-Cat, is charged with a small amount of hydrogen-loaded nickel powder plus some additives, mainly Lithium. The reaction is primarily initiated by heat from resistor coils around the reactor tube. Measurements of the radiated power from the reactor were performed with high-resolution thermal imaging cameras. The measurements of electrical power input were performed with a large bandwidth three-phase power analyzer.
Data were collected during 32 days of running in March 2014. The reactor operating point was set to about 1260 ºC in the first half of the run, and at about 1400 °C in the second half. The measured energy balance between input and output heat yielded a COP factor of about 3.2 and 3.6 for the 1260 ºC and 1400 ºC runs, respectively. The total net energy obtained during the 32 days run was about 1.5 MWh. This amount of energy is far more than can be obtained from any known chemical sources in the small reactor volume.
A sample of the fuel was carefully examined with respect to its isotopic composition before the run and after the run, using several standard methods: XPS, EDS, SIMS, ICP-MS and ICP-AES. The isotope composition in Lithium and Nickel was found to agree with the natural composition before the run, while after the run it was found to have changed substantially. Nuclear reactions are therefore indicated to be present in the run process, which however is hard to reconcile with the fact that no radioactivity was detected outside the reactor during the run.
Update: The CEO of Elforsk, the organization that runs the electric power plants in Sweden, responds to the report and announces the formation of a program to study the phenomenon. Here’s an English translation of his statement: CEO Elforsk Magnus Olofsson – LENR Forum. (Elforsk has been monitoring the work of the Italian-Swedish group for some time now.)
Update 2: Here’s an interview with prominent investor Tom Darden who is CEO of Cherokee Investment Partners, which in turn owns the company Industrial Heat that acquired the rights to Rossi’s eCat technology (see post here) : Raleigh investor Darden still bullish on controversial nuclear technology – Triangle Business Journal