ASTROMAN - Consulting, Executive Search


Eta Carinae's great eruption in the 1840s created the billowing Homunculus Nebula, imaged here by Hubble. Now about a light-year long, the expanding cloud contains enough material to make at least 10 copies of our Sun. Astronomers cannot yet explain what caused this eruption. Photo courtesy of NASA, ESA, and the Hubble SM4 ERO Team

NASA, USA - July 03, 2018

By Francis Reddy
NASA's Goddard Space Flight Center, Greenbelt, Md.

A new study using data from NASA’s NuSTAR space telescope suggests that Eta Carinae, the most luminous and massive stellar system within 10,000 light-years, is accelerating particles to high energies — some of which may reach Earth as cosmic rays.

https://www.nasa.gov/mission_pages/nustar/main/index.html

https://imagine.gsfc.nasa.gov/science/toolbox/cosmic_rays1.html

Eta Carinae shines in X-rays in this image from NASA's Chandra X-ray Observatory.
The colors indicate different energies. Red spans 300 to 1,000 electron volts (eV), green ranges from 1,000 to 3,000 eV and blue covers 3,000 to 10,000 eV.
For comparison, the energy of visible light is about 2 to 3 eV.
NuSTAR observations (green contours) reveal a source of X-rays with energies some three times higher than Chandra detects.
X-rays seen from the central point source arise from the binary’s stellar wind collision.
The NuSTAR detection shows that shock waves in the wind collision zone accelerate charged particles like electrons and protons to near the speed of light. Some of these may reach Earth, where they will be detected as cosmic ray particles.
X-rays scattered by debris ejected in Eta Carinae's famous 1840 eruption may produce the broader red emission.
Photo courtesy of NASA/CXC and NASA/JPL-Caltech

“We know the blast waves of exploded stars can accelerate cosmic ray particles to speeds comparable to that of light, an incredible energy boost,” said Kenji Hamaguchi, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the lead author of the study.
“Similar processes must occur in other extreme environments. Our analysis indicates Eta Carinae is one of them.”

Because cosmic rays carry electric charge, their direction changes as they travel through magnetic fields.
By the time the particles reach us, their paths are completely scrambled, as shown by the blue path.
We can't trace them back to their sources.
Light travels to us straight from their sources, as shown by the purple path.
Photo courtesy of NASA's Goddard Space Flight Center

Astronomers know that cosmic rays with energies greater than 1 billion electron volts (eV) come to us from beyond our solar system.
But because these particles — electrons, protons and atomic nuclei — all carry an electrical charge, they veer off course whenever they encounter magnetic fields.
This scrambles their paths and masks their origins.

The Cosmic Ray Isotope Spectrometer (CRIS - the box on the left of the spacecraft, with a yellow label) on the Advanced Composition Explorer (ACE) spacecraft provides measurements of the isotopes of galactic cosmic ray nuclei ranging from helium to zinc.
ACE launched in August 1997.
Photo courtesy of NASA / Johns Hopkins University Applied Physics Laboratory

Eta Carinae, located about 7,500 light-years away in the southern constellation of Carina, is famous for a 19th century outburst that briefly made it the second-brightest star in the sky. This event also ejected a massive hourglass-shaped nebula, but the cause of the eruption remains poorly understood.

https://www.nasa.gov/content/goddard/astronomers-bring-the-third-dimension-to-a-doomed-stars-outburst

SuperTIGER hanging from the launch vehicle just before its December 2012 launch with Mount Erebus in the background.
SuperTIGER is a cosmic-ray balloon instrument measuring cosmic-rays heavier than iron to explore the source of cosmic rays and their acceleration sites.
SuperTIGER's first flight lasted for 55 days, a record in duration for an Antarctic long duration scientific balloon payload.
Photo courtesy of Ryan Murphy / Washington University

The system contains a pair of massive stars whose eccentric orbits bring them unusually close every 5.5 years.

The stars contain 90 and 30 times the mass of our Sun and pass 140 million miles (225 million kilometers) apart at their closest approach — about the average distance separating Mars and the Sun.

A new shape model of the Homunculus Nebula reveals protrusions, trenches, holes and irregularities in its molecular hydrogen emission.
The protrusions appear near a dust skirt seen at the nebula's center in visible light (inset) but not found in this study, so they constitute different structures.
Photo courtesy of NASA Goddard (inset: NASA, ESA, Hubble SM4 ERO Team)

“Both of Eta Carinae’s stars drive powerful outflows called stellar winds,” said team member Michael Corcoran, also at Goddard.
“Where these winds clash changes during the orbital cycle, which produces a periodic signal in low-energy X-rays we’ve been tracking for more than two decades.”

https://www.nasa.gov/content/goddard/nasa-observatories-take-an-unprecedented-look-into-superstar-eta-carinae

Eta Carinae's great eruption in the 1840s created the billowing Homunculus Nebula, imaged here by Hubble.
Now about a light-year long, the expanding cloud contains enough material to make at least 10 copies of our sun.
Astronomers cannot yet explain what caused this eruption.
Photo courtesy of NASA, ESA, and the Hubble SM4 ERO Team

NASA’s Fermi Gamma-ray Space Telescope also observes a change in gamma rays — light packing far more energy than X-rays — from a source in the direction of Eta Carinae.

But Fermi’s vision isn’t as sharp as X-ray telescopes, so astronomers couldn’t confirm the connection.

Photo courtesy of NASA's Goddard Space Flight Center

To bridge the gap between low-energy X-ray monitoring and Fermi observations, Hamaguchi and his colleagues turned to NuSTAR.

Photo courtesy of NASA's Goddard Space Flight Center

Launched in 2012, NuSTAR can focus X-rays of much greater energy than any previous telescope.

Photo courtesy of NASA's Goddard Space Flight Center

Using both newly taken and archival data, the team examined NuSTAR observations acquired between March 2014 and June 2016, along with lower-energy X-ray observations from the European Space Agency’s XMM-Newton satellite over the same period.

Photo courtesy of NASA's Goddard Space Flight Center

Eta Carinae’s low-energy, or soft, X-rays come from gas at the interface of the colliding stellar winds, where temperatures exceed 70 million degrees Fahrenheit (40 million degrees Celsius).

Photo courtesy of NASA's Goddard Space Flight Center

But NuSTAR detects a source emitting X-rays above 30,000 eV, some three times higher than can be explained by shock waves in the colliding winds.

For comparison, the energy of visible light ranges from about 2 to 3 eV.

Photo courtesy of NASA's Goddard Space Flight Center

The team’s analysis, presented in a paper published on Monday, July 2, in Nature Astronomy, shows that these “hard” X-rays vary with the binary orbital period and show a similar pattern of energy output as the gamma rays observed by Fermi.

https://www.nasa.gov/content/goddard/nasa-observatories-take-an-unprecedented-look-into-superstar-eta-carinae

Photo courtesy of NASA's Goddard Space Flight Center

The researchers say that the best explanation for both the hard X-ray and the gamma-ray emission is electrons accelerated in violent shock waves along the boundary of the colliding stellar winds.

Photo courtesy of NASA's Goddard Space Flight Center

The X-rays detected by NuSTAR and the gamma rays detected by Fermi arise from starlight given a huge energy boost by interactions with these electrons.

Photo courtesy of NASA's Goddard Space Flight Center

Some of the superfast electrons, as well as other accelerated particles, must escape the system and perhaps some eventually wander to Earth, where they may be detected as cosmic rays.

Photo courtesy of NASA's Goddard Space Flight Center

“We’ve known for some time that the region around Eta Carinae is the source of energetic emission in high-energy X-rays and gamma rays”, said Fiona Harrison, the principal investigator of NuSTAR and a professor of astronomy at Caltech in Pasadena, California.
“But until NuSTAR was able to pinpoint the radiation, show it comes from the binary and study its properties in detail, the origin was mysterious.”

Photo courtesy of NASA's Goddard Space Flight Center

NuSTAR is a Small Explorer mission led by Caltech and managed by JPL for NASA's Science Mission Directorate in Washington.

NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI).

The spacecraft was built by Orbital Sciences Corp., Dulles, Virginia, USA.

Photo courtesy of NASA's Goddard Space Flight Center

NuSTAR's mission operations center is at UC Berkeley, and the official data archive is at NASA's High Energy Astrophysics Science Archive Research Center.

ASI provides the mission's ground station and a mirror archive.

Caltech manages JPL for NASA.


Photo courtesy of NASA's Goddard Space Flight Center

For more information on NuSTAR, visit:

https://www.nasa.gov/nustar

http://www.nustar.caltech.edu


Photo courtesy of NASA's Goddard Space Flight Center

Video
Superstar Eta Carinae Shoots Cosmic Rays

https://www.youtube.com/watch?v=B4PwWDNc9qM


Photo courtesy of NASA's Goddard Space Flight Center

Source: NASA

https://www.nasa.gov/

ASTROMAN Magazine - 2018.05.01

NASA Sets Sights on May 5 Launch of InSight Mars Mission

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2498

ASTROMAN Magazine - 2018.04.11

Bound for Mars: Countdown to First Interplanetary Launch from California

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2482

ASTROMAN Magazine - 2018.02.08

SpaceX: Falcon Heavy Test Launch

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2440

ASTROMAN Magazine - 2018.02.02

NASA: Celebrating 60 Years of Groundbreaking U.S. Space Science

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2435

ASTROMAN Magazine - 2018.02.02

NASA: Studying the Van Allen Belts 60 Years After America’s First Spacecraft

http://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2434

ASTROMAN Magazine - 2017.10.04

Lockheed Martin Completes First Flexible Solar Array for LM 2100 Satellite

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2352

ASTROMAN Magazine - 2017.08.24

Airbus' Solar Orbiter on track to launch before next total solar eclipse

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2319

ASTROMAN Magazine - 2017.08.12

Lockheed Martin Successfully Integrates First Modernized A2100 Satellite

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2311

ASTROMAN Magazine - 2017.06.04

Airbus: First high power all-electric satellite, EUTELSAT 172B, launched by Ariane

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2268

ASTROMAN Magazine - 2017.06.03

Boeing Satellite for ViaSat to Significantly Enhance Satellite Broadband Communications

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2267

ASTROMAN Magazine - 2017.04.07

European Space Agency: Exoplanet mission gets ticket to ride

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2226

ASTROMAN Magazine - 2017.03.31

SpaceX conducts historic Falcon 9 re-flight with SES-10 Mission. Lands booster again

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2223

ASTROMAN Magazine - 2017.02.10

European Space Agency: CryoSat reveals lake outbursts beneath Antarctic ice

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2192

ASTROMAN Magazine - 2017.02.07

NASA Highlights Science Launching on Next SpaceX Cargo Mission

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2190

ASTROMAN Magazine - 2016.12.03

Part-Time Scientists and Audi lunar quattro ready to head for the Moon

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2165

ASTROMAN Magazine - 2016.09.11

Airbus Defence and Space's PerúSAT-1 satellite ready for take-off

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2118

ASTROMAN Magazine - 2016.08.14

UAE Space Agency, Mubadala and Lockheed Martin Launch Comprehensive Space-based Workforce Development Program

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2105

ASTROMAN Magazine - 2016.04.09

SpaceX's Falcon 9 rocket will launch the CRS-8 Dragon Spacecraft Mission for NASA

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=2053

ASTROMAN Magazine - 2015.10.02

Flight VA226 success: with Sky Muster and ARSAT-2 in orbit, Arianespace serves Australia and Argentina

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=1972

ASTROMAN Magazine - 2015.07.26

Airbus Defence and Space to build JUICE spacecraft, ESA's next life-tracker inside the Solar System

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=1941

ASTROMAN Magazine - 2015.07.18

Boeing's 10th GPS IIF to Modernize Worldwide GPS System

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=1940

ASTROMAN Magazine - 2015.06.14

Boeing to Build Third All-Electric Propulsion Satellite for ABS to Australia, New Zealand, the Middle East, Russia, South Asia

https://www.astroman.com.pl/index.php?mod=magazine&a=read&id=1929