G1.9+0.3 in an image by the Chandra X-ray Observatory. Credit: X-ray (NASA/CXC/NCSU/K.Borkowski et al.); Optical (DSS)
In 2008, astronomers discovered a star relatively nearby Earth went kablooie some 28,000 light-years away from us. Sharp-eyed astronomers, as they will do, trained their telescopes on it to snap pictures and take observations. Now, fresh observations from the orbiting Chandra X-ray Observatory suggest that supernova was actually a double-barrelled explosion.
This composite picture of G1.9+0.3, coupled with models by astronomers, suggest that this star had a “delayed detonation,” NASA stated.
“First, nuclear reactions occur in a slowly expanding wavefront, producing iron and similar elements. The energy from these reactions causes the star to expand, changing its density and allowing a much faster-moving detonation front of nuclear reactions to occur.”
To explain a bit better what’s going on with this star, there are two main types of supernovas:
In a Type Ia supernova, a white dwarf (left) draws matter from a companion star until its mass hits a limit which leads to collapse and then explosion. Credit: NASA
– Type Ia: When a white dwarf merges with another white dwarf, or picks up matter from a close star companion. When enough mass accretes on the white dwarf, it reaches a critical density where carbon and oxygen fuse, then explodes.
– Type II: When a massive star reaches the end of its life, runs out of nuclear fuel and sees its iron core collapse.
NASA said this was a Type Ia supernova that “ejected stellar debris at high velocities, creating the supernova remnant that is seen today by Chandra and other telescopes.”
In this artist’s conception, a supernova explosion is about to obliterate an orbiting Saturn-like planet. Credit: David A. Aguilar (CfA)
You can actually see the different energies from the explosion in this picture, with red low-energy X-rays, green intermediate energies and blue high-energies.
“The Chandra data show that most of the X-ray emission is “synchrotron radiation,” produced by extremely energetic electrons accelerated in the rapidly expanding blast wave of the supernova. This emission gives information about the origin of cosmic rays — energetic particles that constantly strike the Earth’s atmosphere — but not much information about Type Ia supernovas,” NASA stated.
Also, unusually, this is an assymetrical explosion. There could have been variations in how it expanded, but astronomers are looking to map this out with future observations with Chandra and the National Science Foundation’s Karl G. Jansky Very Large Array.
Check out more information about this supernova in the scientific paper led by North Carolina State University.
NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) is slated to lift off from Wallops Island this September 5th in a spectacular night launch. LADEE will be the first mission departing Wallops to venture beyond low Earth orbit. A joint collaboration between NASA’s Goddard Spaceflight Center & the AMES Research Center, LADEE will study the lunar environment from orbit, including its tenuous exosphere.
Scientists hope to answer some long standing questions about the lunar environment with data provided by LADEE. How substantial is the wispy lunar atmosphere? How common are micro-meteoroid impacts? What was the source of the sky glow recorded by the Surveyor spacecraft and observed by Apollo astronauts before lunar sunrise and after lunar sunset while in orbit?
Glows of the solar corona and crepuscular rays reported by the Apollo 17 astronauts in lunar orbit. (Credit: NASA).
The micro-meteoroid issue is of crucial concern for any future long duration human habitation on the Moon. The Apollo missions were only days in length. No one has ever witnessed a lunar sunrise or sunset from the surface of the Moon, as all six landings occurred on the nearside of the Moon in daylight. (Sunrise to sunset on the Moon takes about two Earth weeks!)
And that’s where amateur astronomers come in. LADEE is teaming up with the Association of Lunar & Planetary Observers (ALPO) and their Lunar Meteoritic Impact Search Program in a call to watch for impacts on the Moon. These are recorded as brief flashes on the nighttime side of the Moon, which presents a favorable illumination after last quarter or leading up into first quarter phase.
We wrote recently about a +4th magnitude flash detected of the Moon on March 17th of this year. That explosion was thought to have been caused by a 35 centimetre impactor which may have been associated with the Eta Virginid meteor shower. The impact released an explosive equivalent of five tons of TNT and has set a possible new challenge for Moon Zoo volunteers to search for the resulting 6 metre crater.
An artist’s illustration of a meteoroid impact on the Moon. (Credit: NASA).
We’ve also written about amateur efforts to document transient lunar phenomena and studies attempting to pinpoint a possible source of these spurious glows and flashes on the Moon observed over the years.
NASA’s Meteoroid Environment Office is looking for dedicated amateurs to take part in their Lunar Impact Monitoring campaign. Ideally, such an observing station should utilize a telescope with a minimum aperture of 8 inches (20cm) and be able to continuously monitor and track the Moon while it’s above the local horizon. Most micro-meteoroid flashes are too fast and faint to be seen with the naked eye, and thus video recording will be necessary. A typical video configuration for the project is described here. Note the high frame rate and the ability to embed a precise time stamp is required. I’ve actually run WWV radio signals using an AM short wave radio transmitting in the background to accomplish this during occultations.
Finally, you’ll need a program called LunarScan to analyze those videos for evidence of high speed flashes. LunarScan is pretty intuitive. We used the program to analyze video shot during the 2010 Total Lunar Eclipse for any surreptitious Geminid or Ursid meteors.
Brian Cudnik, coordinator of the Lunar Meteoritic Impact Search section of the ALPO, noted in a recent forum post that we’re approaching another optimal window to accomplish these sorts of observations this weekend, with the Moon headed towards last quarter on June 30th.
An example of an impact flash recorded by the Automated & Lunar Meteor Observatory video cameras based at the Marshall Spaceflight Center in Huntsville, Alabama.
Interestingly, the June Boötids are currently active as well, with historical sporadic rates of anywhere from 10-100 per hour. In 1975, seismometers left by Apollo astronauts detected series of impacts on June 24th thought to have been caused by one of two Taurid meteor swarms the Earth passes through in late June, another reason to be vigilant this time of year.
Don’t have access to a large telescope or sophisticated video gear? You can still participate and make useful observations.
LADEE is also teaming up with JPL and the Lewis Center for Educational Research to allow students track the spacecraft en route to the Moon. Student groups will be able to remotely access the 34-metre radio telescopes based at Goldstone, California that form part of NASA’s Deep Space Communications Network. Students will be able to perform Doppler measurements during key mission milestones to monitor the position and status of the spacecraft during thruster firings.
And backyard observers can participate in another fashion, using nothing more than their eyes and patience. Meteor streams that are impacting the Moon affect the Earth as well. The International Meteor Organization is always looking for information from dedicated observers in the form of meteor counts. The Perseids, an “Old Faithful” of meteor showers, occurs this year around August 12th under optimal conditions, with the Moon only five days past New. This is also three weeks prior to the launch of LADEE.
Whichever way you choose to participate, be sure to follow the progress of LADEE and our next mission to study Earth’s Moon!
-Listen to Universe Today’s Nancy Atkinson and her interview with Brian Day of the NASA Lunar Science Institute.
-Also listen to the 365 Days of Astronomy interview with Brian Day and Andy Shaner from the Lunar Planetary institute on the upcoming LADEE mission.
37 separate images showing the movement of the Moon as it rises behind the buildings in downtown Houston, Texas on June 22, 2013. Credit and copyright: Sergio Garcia Rill/SGR Photo.
While we recently posted a huge batch of images from the recent “Super Moon,” this new image from Sergio Garcia Rill in Houston is something special. It’s a composite photo of the Moonrise on June 22nd, and is a mosaic made from 37 separate images that show the Moon rising over the course of three hours, with the buildings of downtown Houston in the foreground.
“I stayed in place for over three hours,” Sergio explained on Flickr. “The hardest part was selecting which shots showed a sequential movement of the Moon, since I was altering shutter speeds between shots to compensate for changing light conditions.”
The full Moon of June 2013 was at perigee — or at its closest point in its orbit to Earth, and appeared up to 14% bigger and 30% brighter than other full Moons of 2013.
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
The red filter on the Sunset app doesn't ruin your night vision.
Ever have to take a call while stargazing, or do you use astronomical apps on your phone, only to have the white screen ruin your night vision? A new app called Sunset is a screen filter that essentially adds a dimmed red-color filter onto an Android device’s screen so you can use your smartphone during those extra dark moments and not lose your dark-adapted night-vision.
The app’s description says it best:
Sunset is a screen filter adds an additional layer of dimming color to help soothe your eyes during those extra dark hours. Perfect for astronomers/stargazers looking to preserve their night vision, late night smartphone users, and movie theater texters. Sunset goes darker than Android’s brightness settings to provide your eyes with that extra layer of comfort.
Sunset is easy to use, too. Just select a color theme, choose the maximum intensity, and hit start. The color themes are specifically designed to help your eyes in different environments, as there are several other color options.
The Sunset app is just 99 cents, USD, but the app’s creator Rohan Puri will send a refund to the first 20 Universe Today readers who buy this app. Just send your e-mail via Direct Message on Twitter to @RohanSPuri after your purchase, and you will receive a full refund.
More bad news on the exoplanet-hunting front: While the final fate of the Kepler spacecraft remains unknown, the CoRoT (Convection, Rotation and Planetary Transits) satellite has now been officially shut down. CoRoT suffered a computer failure on November, 2, 2012 and although the spacecraft is capable of receiving navigational commands, the French Space Agency CNES reports it can no longer retrieve data from its 30-centimeter telescope. After a valiant effort to try and restore the computer, CNES announced this week that the spacecraft has been retired. CoRoT’s journey will come to a fiery end as it will be deorbited and it will burn up on re-entry in Earth’s atmosphere.
While it’s always hard to see the end of successful mission, we can’t be too sad about CoRoT, however. The mission lasted twice as long as expected and it gathered a remarkable haul of exoplanets. CoRoT looked for planetary transits — a dimming in brightness of the host star as a planet crossed in front. CoRoT was the first mission to find a planet using the transit method.
In all, CoRoT has spotted 32 confirmed planets and at least 100 more are awaiting confirmation. The mission also allowed astronomers to study the stellar physics and the interior of stars.
This is not the first computer failure for the mission. CoRoT launched in December of 2006, and in 2009 the main computer failed and has since been running on the backup computer. When the second computer failed in November, engineering teams have tried to reboot both computers, with no success.
But space radiation is tough on spacecraft, and after enduring 6 years of intense bombardment by high-energy particles in space, both computers have been deemed unrecoverable.
CNES said a series of operations will be performed to lower CoRoT’s orbit and conduct some technology experiments before passivating and deorbiting the satellite. Its journey will end as it burns up on re-entry in Earth’s atmosphere.
Family portrait of the first 15 CoRoT planets. Credit: Patrice Amoyel (CNES)
CoRoT discovered a diverse array of planets, mostly gas giants. Some of the planets discovered, like CoRoT-7b, orbit their star in less than 24 hours and have a blistering hot surface, while others like CoRoT-9b have an orbital period of 95 days and is one of very few known “warm” transiting exoplanets.
CoRoT was also the first to obtain measurements of the radius of brown dwarves, intermediate objects between a planet and a star, and literally opened up a whole new field of study of temporal analysis of the micro-variability of stars by measuring the frequencies and amplitudes of stellar vibrations with unprecedented precision.
CNES did not provide a timetable for CoRoT’s demise, but we’ll keep you posted.
An artist's conception of an exoplanet transiting its home star. Credit: NASA's Goddard Space Flight Center
As Earthlings, we’re so used to thinking about planets being in simple orbits around a single star. But the Sun likely didn’t begin its life alone. It formed as part of a cluster of stars, all feeding from the same well of gas.
Could star clusters also host planets? Or do they have to wait for the little guys until the stars evolve and move further apart? Well, astronomers have actually just found planets — yes, two planets — orbiting Sun-like stars in a cluster 3,000 light-years from Earth.
These are the third and fourth star cluster planets yet discovered, but the first found “transiting” or passing across the face of their stars as seen from Earth. (The others were found through detecting gravitational wobbles in the star.)
This is no small feat for a planet to survive. In a telescope, a star cluster might look pretty benign, but up close it’s pretty darn harsh. A press release about the discovery used a lot of words like “strong radiation”, “harsh stellar winds” and “stripping planet-forming materials” in a description of what NGC 6811 would feel like.
An artist’s conception of a planet in a star cluster. Credit: Michael Bachofner
“Old clusters represent a stellar environment much different than the birthplace of the Sun and other planet-hosting field stars,” stated lead author Soren Meibom of the Harvard-Smithsonian Center for Astrophysics.
“We thought maybe planets couldn’t easily form and survive in the stressful environments of dense clusters, in part because for a long time we couldn’t find them.”
The planets are known as Kepler-66b and Kepler-67b, and are both approaching the size of Neptune (which is four times the size of Earth). Their parent cluster, NGC 6811, is one billion years old. Astronomers are still puzzled as to how these little worlds survived for so long.
“Highly energetic phenomena including explosions, outflows and winds often associated with massive stars would have been common in the young cluster,” stated the journal paper in Nature.
“The degree to which the formation and evolution of planets is influenced by a such a dense and dynamically and radiatively hostile environment is not well understood, either observationally or theoretically.”
Check out the entire study in the latest edition of Nature.
Curtain of Crepuscular Rays at Dawn, on June 17, 2013. Taken from Coral Towers Observatory in Australia. Credit and copyright: Joseph Brimacombe.
Prolific astrophotographer and Australian astronomer Joseph Brimacombe captured this beautiful wide-field view of crepuscular rays from the Sun last week. You definitely want to click on this image to see a larger view on Flickr. This image is made of seven frames; three exposures each. Brimacombe was lucky to get this shot; just seven minutes later (see the view here), the spectacular curtain of rays were gone.
The word crepuscular means “relating to twilight,” and these rays occur when objects such as mountain peaks or clouds partially shadow the Sun’s rays, usually when the Sun is low on the horizon. These rays are visible only when the atmosphere contains enough haze or dust particles so that sunlight in unshadowed areas can be scattered toward the observer.
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
Screenshot showing the Shenzou-10 capsule on the ground following a successful mission for China.
China successfully completed its longest human space mission as the Shenzhou-10 spacecraft and its crew of two men and one woman returned safely to Earth. The return capsule landed via parachute at 8:07 am local time (0007 UTC) Wednesday, June 26, 2013 on the grasslands of north China’s Inner Mongolia region. The 15-day “Divine Vessel” mission is part of the Chinese space program’s objective of building a permanent space station by 2020.
In the video below, enthusiastic applause comes when the parachute deploys and at other milestones of the return. The crew was quickly greeted and a smiling Nie Haisheng, the commander of the mission, emerged from the capsule first, and was followed by female astronaut Wang Yaping, and crewmember Zhang Xiaoguang.
“At this moment what I most want to say is that space is our dream and our motherland is forever our home,” Nie said. “I wish our motherland to thrive even more and our people to become happier and happier. I thank the entire nation for their concern and support for us.”
During the mission, the Shenzou spacecraft docked with China’s orbiting space module Tiangong-1 in tests intended to prepare for the building of the space station. The crew also spoke via video to school children in China, showing how different objects behave in zero-G. The crew conducted several experiments and medical tests while in space. The official mission duration was 14 days 14 hours and 29 minutes.
This was China’s fifth manned space mission since 2003. China plans to launch the Tiangong-2 space lab around 2015, according to the official Chinese Xinhua news agency, quoting Wang Zhaoyao, director of China’s manned space program office. He said there are plans to put an experimental core module of a space station in orbit in 2018, with the manned space station itself being built around 2020.
Besides building a space station, China also hopes to send astronauts to the Moon.
So many of the forces in space depend on equilibrium, that point where forces perfectly balance out. It defines the shape of stars, the orbits of planets, even the forces at the cores of galaxies. Let’s take a look at how parts of the Universe are in perfect balance.
In the end, everything dies, even plucky space robots. Today we examine the last days of a series of missions. How do spacecraft tend to die, and what did in such heroes as Kepler, Spirit, and Galileo (the missions… not the people).
