Tag Archives: Black Hole

Free Astronomy Magazine – May-June 2016 Issue Available For Reading And Download

Greetings, fellow astrophiles!

2016may10_freeastroThe most recent issue of Free Astronomy Magazine (May-June, 2016) is available for your reading and downloading pleasure at www.astropublishing.com (click the link to go directly to the issue).

Free Astronomy Magazine was featured as the first of a series of articles on great free online content for amateur astronomers (see A Universe Of Free Resources Part 1) and we’ll be keeping track of future publications under the Online Resources category on the CNYO website.

You can find previous Free Astronomy Magazine issues by checking out our Free Astronomy Magazine Category (or look under the Education link in our menu).

For those wanting a quick look at what the issue has to offer, the Table of Contents is reproduced below.

May-June 2016

The web browser-readable version of the issue can be found here:

May/Jun 2016 – www.astropublishing.com/FAM-2-2016/files/assets/basic-html/index.html

For those who want to jump right to the PDF download (30 MB), Click here: May-June 2016

2016may10_freeastro_toc

NASA Space Place – How Will We Finally Image The Event Horizon Of A Black Hole?

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in December, 2015.

By Dr. Ethan Siegel

2013february2_spaceplaceOne hundred years ago, Albert Einstein first put forth his theory of General Relativity, which laid out the relationship between spacetime and the matter and energy present within it. While it successfully recovered Newtonian gravity and predicted the additional precession of Mercury’s orbit, the only exact solution that Einstein himself discovered was the trivial one: that for completely empty space. Less than two months after releasing his theory, however, the German scientist Karl Schwarzschild provided a true exact solution, that of a massive, infinitely dense object, a black hole.

One of the curious things that popped out of Schwarzschild’s solution was the existence of an event horizon, or a region of space that was so severely curved that nothing, not even light, could escape from it. The size of this event horizon would be directly proportional to the mass of the black hole. A black hole the mass of Earth would have an event horizon less than a centimeter in radius; a black hole the mass of the sun would have an event horizon just a few kilometers in radius; and a supermassive black hole would have an event horizon the size of a planetary orbit.

Our galaxy has since been discovered to house a black hole about four million solar masses in size, with an event horizon about 23.6 million kilometers across, or about 40 percent the size of Mercury’s orbit around the sun. At a distance of 26,000 light years, it’s the largest event horizon in angular size visible from Earth, but at just 19 micro-arc-seconds, it would take a telescope the size of Earth to resolve it – a practical impossibility.

But all hope isn’t lost! If instead of a single telescope, we built an array of telescopes located all over Earth, we could simultaneously image the galactic center, and use the technique of VLBI (very long-baseline interferometry) to resolve the black hole’s event horizon. The array would only have the light-gathering power of the individual telescopes, meaning the black hole (in the radio) will appear very faint, but they can obtain the resolution of a telescope that’s the distance between the farthest telescopes in the array! The planned Event Horizon Telescope, spanning four different continents (including Antarctica), should be able to resolve under 10 micro-arc-seconds, imaging a black hole directly for the first time and answering the question of whether or not they truly contain an event horizon. What began as a mere mathematical solution is now just a few years away from being observed and known for certain!

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Astronomers have detected the largest X-ray flare ever from the supermassive black hole at the center of the Milky Way, known as <a href=

Sagittarius A* (Sgr A*), using NASA's Chandra X-ray Observatory. This event was 400 times brighter than the usual X-ray output from Sgr A*. The main portion of this graphic shows the area around Sgr A* in a Chandra image where low, medium, and high-energy X-rays are red, green, and blue respectively. The inset box contains an X-ray movie of the region close to Sgr A* and shows the giant flare, along with much steadier X-ray emission from a nearby magnetar, to the lower left. A magnetar is a neutron star with a strong magnetic field.” width=”640″ height=”640″ /> Astronomers have detected the largest X-ray flare ever from the supermassive black hole at the center of the Milky Way, known as Sagittarius A* (Sgr A*), using NASA’s Chandra X-ray Observatory. This event was 400 times brighter than the usual X-ray output from Sgr A*. The main portion of this graphic shows the area around Sgr A* in a Chandra image where low, medium, and high-energy X-rays are red, green, and blue respectively. The inset box contains an X-ray movie of the region close to Sgr A* and shows the giant flare, along with much steadier X-ray emission from a nearby magnetar, to the lower left. A magnetar is a neutron star with a strong magnetic field.

About NASA Space Place

With articles, activities, crafts, games, and lesson plans, NASA Space Place encourages everyone to get excited about science and technology. Visit spaceplace.nasa.gov (facebook|twitter) to explore space and Earth science!

NASA News Digest: Space Science (And A Remembrance) For 2 February – 3 March 2015

Greetings fellow astrophiles,

The NASA News service provides up-to-date announcements of NASA policy, news events, and space science. A recent selection of space science articles are provided below, including direct links to the full announcements. Those interested in receiving these news announcements directly from NASA can subscribe to their service by sending an email to:

hqnews-request@newsletters.nasa.gov?subject=subscribe

NASA Study Finds Carbon Emissions Could Dramatically Increase Risk Of U.S. Megadroughts

RELEASE 15-020 (Click here for the full article) – 12 February 2015

Droughts in the U.S. Southwest and Central Plains during the last half of this century could be drier and longer than drought conditions seen in those regions in the last 1,000 years, according to a new NASA study.

The study, published Thursday in the journal Science Advances, is based on projections from several climate models, including one sponsored by NASA. The research found continued increases in human-produced greenhouse gas emissions drives up the risk of severe droughts in these regions.

“Natural droughts like the 1930s Dust Bowl and the current drought in the Southwest have historically lasted maybe a decade or a little less,” said Ben Cook, climate scientist at NASA’s Goddard Institute for Space Studies and the Lamont-Doherty Earth Observatory at Columbia University in New York City, and lead author of the study. “What these results are saying is we’re going to get a drought similar to those events, but it is probably going to last at least 30 to 35 years.”

For more information about NASA’s Earth science activities, visit: www.nasa.gov/earthrightnow

NASA, ESA Telescopes Give Shape To Furious Black Hole Winds

RELEASE 15-021 (Click here for the full article) – 19 February 2015

2015mar3_15_021_nustarNASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) and ESA’s (European Space Agency) XMM-Newton telescope are showing that fierce winds from a supermassive black hole blow outward in all directions — a phenomenon that had been suspected, but difficult to prove until now.

This discovery has given astronomers their first opportunity to measure the strength of these ultra-fast winds and prove they are powerful enough to inhibit the host galaxy’s ability to make new stars.

“We know black holes in the centers of galaxies can feed on matter, and this process can produce winds. This is thought to regulate the growth of the galaxies,” said Fiona Harrison of the California Institute of Technology (Caltech) in Pasadena, California. Harrison is the principal investigator of NuSTAR and a co-author on a new paper about these results appearing in the journal Science. “Knowing the speed, shape and size of the winds, we can now figure out how powerful they are.”

For more information, visit: www.nasa.gov/nustar and www.nustar.caltech.edu/

New NASA Earth Science Missions Expand View Of Our Home Planet

RELEASE 15-025 (Click here for the full article) – 26 February 2015

Four new NASA Earth-observing missions are collecting data from space – with a fifth newly in orbit – after the busiest year of NASA Earth science launches in more than a decade.

On Feb. 27, 2014, NASA and the Japan Aerospace Exploration Agency (JAXA) launched the Global Precipitation Measurement (GPM) Core Observatory into space from Japan. Data from GPM and the other new missions are making observations and providing scientists with new insights into global rain and snowfall, atmospheric carbon dioxide, ocean winds, clouds, and tiny airborne particles called aerosols.

“This has been a phenomenally productive year for NASA in our mission to explore our complex planet from the unique vantage point of space,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate in Washington. “Combined with data from our other Earth-observing spacecraft, these new missions will give us new insights into how Earth works as a system.”

Video and images of these new NASA data products are available online at: go.nasa.gov/newearthviews

For more information about NASA’s Earth science activities, visit: www.nasa.gov/earthrightnow

Media Invited to See Bigelow Expandable Space Station Module Ahead Of Shipment To NASA

RELEASE 15-038 (Click here for the full article) – 3 March 2015

2015mar3_15_038NASA and Bigelow Aerospace invite media to a photo and interview opportunity at 10 a.m. PST on Thursday, March 12, at Bigelow Aerospace’s North Las Vegas facility to mark the completion of all major milestones on the Bigelow Expandable Activity Module (BEAM).

Reporters will have the opportunity to see and photograph the BEAM before it’s shipped to NASA’s Kennedy Space Center in Florida for launch to the International Space Station later this year. Robert Bigelow, president and founder of Bigelow Aerospace, and William Gerstenmaier, NASA’s associate administrator for Human Exploration and Operations, will conduct a joint question and answer session with media.

For more information about Bigelow Aerospace, visit: www.bigelowaerospace.com

For more information about the BEAM, visit: www.nasa.gov/mission_pages/station/news/beam_feature.html

NASA Administrator Remembers Leonard Nimoy

RELEASE 15-029 (Click here for the full article) – 27 February 2015

2015mar3_spockThe following is a statement from NASA Administrator Charles Bolden on the passing of Leonard Nimoy:

“Leonard Nimoy was an inspiration to multiple generations of engineers, scientists, astronauts, and other space explorers. As Mr. Spock, he made science and technology important to the story, while never failing to show, by example, that it is the people around us who matter most.

“NASA was fortunate to have him as a friend and a colleague. He was much more than the Science Officer for the USS Enterprise. Leonard was a talented actor, director, philanthropist, and a gracious man dedicated to art in many forms.

“Our thoughts and prayers are with his family, friends, and the legions of Star Trek fans around the world.”

NASA Space Place – Minor Mergers Have Massive Consequences For Black Holes

Poster’s Note: One of the many under-appreciated aspects of NASA is the extent to which it publishes quality science content for children and Ph.D.’s alike. NASA Space Place has been providing general audience articles for quite some time that are freely available for download and republishing. Your tax dollars help promote science! The following article was provided for reprinting in January, 2015.

By Dr. Ethan Siegel

2013february2_spaceplaceWhen you think of our sun, the nearest star to our world, you think of an isolated entity, with more than four light years separating it from its next nearest neighbor. But it wasn’t always so: billions of years ago, when our sun was first created, it very likely formed in concert with thousands of other stars, when a giant molecular cloud containing perhaps a million times the mass of our solar system collapsed. While the vast majority of stars that the universe forms—some ninety-five percent—are the mass of our sun or smaller, a rare but significant fraction are ultra-massive, containing tens or even hundreds of times the mass our star contains. When these stars run out of fuel in their cores, they explode in a fantastic Type II supernova, where the star’s core collapses. In the most massive cases, this forms a black hole.

Over time, many generations of stars—and hence, many black holes—form, with the majority eventually migrating towards the centers of their host galaxies and merging together. Our own galaxy, the Milky Way, houses a supermassive black hole that weighs in at about four million solar masses, while our big sister, Andromeda, has one nearly twenty times as massive. But even relatively isolated galaxies didn’t simply form from the monolithic collapse of an isolated clump of matter, but by hierarchical mergers of smaller galaxies over tremendous timescales. If galaxies with large amounts of stars all have black holes at their centers, then we should be able to see some fraction of Milky Way-sized galaxies with not just one, but multiple supermassive black holes at their center!

It was only in the early 2000s that NASA’s Chandra X-ray Observatory was able to find the first binary supermassive black hole in a galaxy, and that was in an ultra-luminous galaxy with a double core. Many other examples were discovered since, but for a decade they were all in ultra-massive, active galaxies. That all changed in 2011, with the discovery of two active, massive black holes at the center of the regular spiral galaxy NGC 3393, a galaxy that must have undergone only minor mergers no less than a billion years ago, where the black hole pair is separated by only 490 light years! It’s only in the cores of active, X-ray emitting galaxies that we can detect binary black holes like this. Examples like NGC 3393 and IC 4970 are not only confirming our picture of galaxy growth and formation, but are teaching us that supermassive relics from ancient, minor mergers might persist as standalone entities for longer than we ever thought!

Check out some cool images and artist reconstructions of black holes from Chandra: chandra.harvard.edu/photo/category/blackholes.html

Kids can learn all about Black Holes from this cool animation at NASA’s Space Place: spaceplace.nasa.gov/black-holes.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

ngc3393.en

Caption: NGC 3393 in the optical (L) by M. Malkan (UCLA), HST, NASA (L); NGC 3393 in the X-ray and optical (R), composite by NASA / CXC / SAO / G. Fabbiano et al. (X-ray) and NASA/STScI (optical).

About NASA Space Place

The goal of the NASA Space Place is “to inform, inspire, and involve children in the excitement of science, technology, and space exploration.” More information is available at their website: http://spaceplace.nasa.gov/