The Ring Nebula is a planetary nebula about 2,000 light-years from Earth and measures roughly 1 light-year across. It is located in the constellation Lyra, and is a popular target for amateur astronomers.
But this new image, done as a collaboration between amateur astronomers Terry Hancock of Michigan and Fred Herrmann of Alabama, is amazing, with detail usually only seen from large ground-based observatories or space telescopes, particularly the detail of the gaseous outer shell of the nebula.
With over 25 hours of total exposure time, this is a remarkably deep exposure which explores the looping filaments of glowing gas. The collaborative effort combined data from two different telescopes, and both Hancock and Herrmann used Astro-Tech 12″ Ritchey-Chrétien astrographs.
Below is another view, a wide field version:
Hancock’s data is from 2012 and 2013 using a QHY9 monochrome CCD and Herrmann’s data is from an SBIG STT-8300 monochrome CCD. Data was collected over 14 nights and six one hour narrow-band hydrogen alpha exposures were taken in order to show the dimmer outer shell.
Hancock explained on G+ that the lighter hydrogen forms the outer reddish envelope while the heavier blue-green oxygen remains about the core. “The gases in the expanding shell are illuminated by the radiation of the central white dwarf, and the glow is still 200 times brighter than our Sun,” he said.
Also visible in the images is the barred spiral galaxy IC 1296.
Recent views from the Hubble Space Telescope of the Ring Nebula showed how the ‘ring’ is really more similar to a football-shaped jelly donut, and Hancock and Herrmann’s view shows that shape as well.
Want to join the hunt for new galaxies? During a special G+ Hangout today, June 5, a team of astronomers will share how you can help them find faint and distant galaxies by joining a search they’ve called “Space Warps.” This is a new project from the Zooniverse. The team of astronomers will discuss gravitational lensing, a strange phenomenon that actually makes it possible for us to see a galaxy far away and otherwise hidden by clusters of galaxies in front of them. They will also answer your questions about their ongoing search for distant galaxies, what this reveals about the cosmos, and how astronomers are beginning to fill out our picture of the universe.
You can watch in the window below, and the webcast starts at 21:00 UTC (2:00 p.m. PDT, 5:00 pm EDT). You can take part in thise live Google+ Hangout, and have your questions answered by submitting them before or during the webcast. Email questions to [email protected]or send a message on Twitter with the hashtag #KavliAstro.
If you miss it live, you can watch the replay below, as well.
The participants:
• ANUPREETA MORE is a co-Principal Investigator of Space Warps and a postdoctoral fellow at the Kavli Institute for the Physics and Mathematics of the Universe at the University of Tokyo.
• PHILIP MARSHALL is a researcher at the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University and SLAC.
• ARFON SMITH is Director of Citizen Science at the Adler Planetarium in Chicago and Technical Lead of Zooniverse (www.zooniverse.org).
Do you live in the southern hemisphere? Are you tired of all those views of the Moon that favor celestial north as up? Well here’s a video just for you from the good folks at the GSFC Scientific Visualization Center — it shows the full 2013 year of lunar phases and libration as seen from Earth’s southern half using data gathered by NASA’s Lunar Reconnaissance Orbiter. (Because what’s so great about north, anyway?)
Each frame represents one hour. Side graphs indicate the Moon’s orbit position, sub-Earth and subsolar points, and distance from the Earth at true scale. Awesome! Um, I mean… bonzer!
And what’s up with all that wobbling around? Find out more below:
The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 24 seconds, as it is in this animation, our changing view of the Moon makes it look like it’s wobbling. This wobble is called libration.
The word comes from the Latin for “balance scale” and refers to the way such a scale tips up and down on alternating sides.
The Moon is subject to other motions as well. It appears to roll back and forth around the sub-Earth point (the location on the Moon’s surface where the Earth appears directly overhead, at the zenith.) The roll angle is given by the position angle of the axis, which is the angle of the Moon’s north pole relative to celestial north. The Moon also approaches and recedes from us, appearing to grow and shrink. The two extremes, called perigee (near) and apogee (far), differ by more than 10%.
Read more and see the current phase of the Moon (bottom up) on the GSFC Dial-a-Moon page here.
A nebula named after a cat’s paw may be a stealthy spot for a lot of star birth. New observations of NGC 6334 revealed fainter stars than ever before seen, leading astronomers to believe there could be many star babies within the nebula.
“The observations acquired with NEWFIRM allowed us to identify and separate out the large number of contaminating sources, including background galaxies and cool stellar giants in the galactic plane to obtain a more complete census of the newly-formed stars,” stated Lori Allen, an NOAO team member.
A team led by Sarah Willis, a Ph.D. student at Iowa State University, recorded the stars they saw. Brightness ranged to about equivalent to our sun, to those that are a million times fainter. Then the scientists performed an extrapolation to determine how many lower-mass stars within the region.
“This is analogous to saying that if we observe the adult population in a town, we can estimate how many children live in the town, even if we can’t see them. In this way, the team can derive an estimate of the total number of stars in the region, and the efficiency with which stars are forming,” the NOAO stated.
One popular myth about space exploration is that the Great Wall of China is the only human-built structure that can be seen from space. But this is not true. The reality is that you can’t easily see the Great Wall with the unaided eye, even from low Earth orbit. And certainly, the Apollo astronauts couldn’t see it from the Moon, even though that urban legend has been widely circulated.
Canadian astronaut Chris Hadfield, who spent five months aboard the International Space Station in 2012-2013, reiterated the facts about the Great Wall’s visibility from space.
“The Great Wall of China is not visible from orbit with the naked eye,” Hadfield said via Twitter. “It’s too narrow, and it follows the natural contours and colours [of the landscape].”
Additionally, when China’s first astronaut, Yang Liwei, went into space in 2003, he said that he couldn’t see the structure of the Great Wall from out his capsule window.
NASA has confirmed that US astronaut Leroy Chiao took what is thought to be the first verifiable image of the Great Wall of China from out his window on the International Space Station in 2004, using a zoom lens. He photographed a region of Inner Mongolia, about 200 miles north of Beijing, but said Chiao himself said he didn’t see the wall with his unaided eyes, and wasn’t sure if the picture showed it.
The image above was taken with a 180mm zoom lens. If you can’t make out the Great Wall in the image above, here’s a cropped version of the image with annotation to help make out the feature:
What human-made structures are visible from space? Space Station astronauts have said the ancient pyramids at Giza are relatively easy to see out the window, but most visible are roads or long bridges across straits. Those features stand out as straight lines on the landscape, such as this image shared by Chris Hadfield:
And, of course, at night cities are visible from space because the light they produce. You can see some stunning images here that NASA released in 2012 from the Suomi NPP satellite of city lights from space.
The Apollo astronauts confirmed that you can’t see the Great Wall of China from the Moon. In fact, all you can see from the Moon is the white and blue marble of our home planet.
With all of the human construction, many buildings and other structures can be seen from space. But you can’t see the Great Wall of China from space.
The tornado that devastated the region around Moore and Newcastle, Oklahoma on May 20, 2013 has been determined to be an EF-5 tornado, the most severe on the enhanced Fujita scale, and has been called one of the most powerful and destructive tornadoes ever recorded. In this new image taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite, the scar of destruction on the Oklahoma landscape is clearly visible from space. In this false-color infrared image, red highlights vegetation, and the tornado track appears as a beige strip running west to east across this image; the color reveals the lack of vegetation in the wake of the storm.
According to the National Weather Service, the tornado was on the ground for 39 minutes, ripping across 17 miles (27 kilometers) from 4.4 miles west of Newcastle to 4.8 miles east of Moore. At its peak, the funnel cloud was 1.3 miles (2.1 kilometers) wide and wind speeds reached 210 miles (340 km) per hour. The storm killed at least 24 people, injured 377, and affected nearly 33,000 in some way.
In this image, infrared, red, and green wavelengths of light have been combined to better distinguish between water, vegetation, bare ground, and human developments. Water is blue. Buildings and paved surfaces are blue-gray.
You can also see an interactive satellite map from Google and Digital Globe, showing detail of every building that was damaged or destroyed. Satellite data like this are helping to assist in the recovery and rebuilding of the area. Satellite imagery can provide a systematic approach to aiding, monitoring and evaluating the process.
The highly acclaimed and mind-expanding documentary, ‘Journey of the Universe’, which aired on PBS in 2011, looked at modern science and ancient wisdom to ask the eternal question, why are we on this planet? Hosted by philosopher Brian Thomas Swimme, the film was a journey through time, looking at the evolution of our understandings of science and the world around us, and how we have looked out to try and determine our connection to the cosmos.
Now, the same producers have a new series called ‘Journey of the Universe: Conversations,’ which presents interviews hosted by Mary Evelyn Tucker, an historian of religions, talking with some of the greatest minds of our time — scientists, historians and environmentalists — to explore the unfolding story of Earth, the Universe, and how we should responding to global and environmental issues of the day.
Universe Today has one copy of ‘Journey of the Universe’ and two DVD sets of Journey of the Universe: Conversations’ to give away to our readers. The DVD sets are a 10 hour, 20-part, 4-disc set, just released today. The set is about $80 USD on Amazon.
In order to be entered into the giveaway drawing, just put your email address into the box at the bottom of this post (where it says “Enter the Giveaway”) before Monday June 10, 2013. We’ll send you a confirmation email, so you’ll need to click that to be entered into the drawing.
“Conversations” follows in the traditions of discussions by Thomas Berry and Joseph Campbell, and deliberates history and future of the Universe, delving into discussions of science, technology, literature, religion and philosophy.
Speaking of shots of awe, here’s an amazingly beautiful wide-field view of IC 443 (also known as the Jellyfish Nebula) a supernova remnant, as well as IC 444, a small reflection nebula, together in the constellation Gemini, surrounded by a sea of stars. Astrophotographer Martin Campbell put this image together by stacking 30 images, totalling 1.5 hours of exposure. His equipment was a Takahashi Epsilon 180 and a modified Canon 5D MKII DSLR.
Gorgeous!
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.
Ever find yourself thinking about how the Universe came to be, or how humans have evolved to their current level of intelligence, or just why that certain song tugs at your heartstrings? Self-professed wonder junkie Jason Silva has a new video series that feature his reflections on the human condition, the nature of what it means to be alive, and the role of philosophy in everyday life.
Called “Shots of Awe” these under three-minute videos are what Silva calls “inspired nuggets of techno-rapture,” and every week can provide a nudge to contemplate your life; whether it be to look at the complex systems of society, technology, or the beauty of nature and science.
Hang on, though; Silva’s faster-than-thought dialogue takes you for a ride that might leave you spinning … but in a good way!
There are new episodes every Tuesday and below is today’s newest, titled “Singularity.”
Some of the most violent events in our Universe were the topic of discussion this morning at the 222nd meeting of the American Astronomical Society in Indianapolis, Indiana as researchers revealed recent observations of light echoes seen as the result of stellar explosions.
A light echo occurs when we see dust and ejected material illuminated by a brilliant nova. A similar phenomenon results in what is termed as a reflection nebula. A star is said to go nova when a white dwarf star siphons off material from a companion star. This accumulated hydrogen builds up under terrific pressure, sparking a brief outburst of nuclear fusion.
A very special and rare case is a class of cataclysmic variables known as recurrent novae. Less than dozen of these types of stars are known of in our galaxy, and the most famous and bizarre case is that of T Pyxidis.
Located in the southern constellation of Pyxis, T Pyxidis generally hovers around +15th magnitude, a faint target even in a large backyard telescope. It has been prone, however, to great outbursts approaching naked eye brightness roughly every 20 years to magnitude +6.4. That’s a change in brightness almost 4,000-fold.
But the mystery has only deepened surrounding this star. Eight outbursts were monitored by astronomers from 1890 to 1966, and then… nothing. For decades, T Pyxidis was silent. Speculation shifted from when T Pyxidis would pop to why this star was suddenly undergoing a lengthy phase of silence.
Could models for recurrent novae be in need of an overhaul?
T Pyxidis finally answered astronomers’ questions in 2011, undergoing its first outburst in 45 years. And this time, they had the Hubble Space Telescope on hand to witness the event.
In fact, Hubble had just been refurbished during the final visit of the space shuttle Atlantis to the orbiting observatory in 2009 on STS-125 with the installation of its Wide Field Camera 3, which was used to monitor the outburst of T Pyxidis.
The Hubble observation of the light echo provided some surprises for astronomers as well.
“We fully expected this to be a spherical shell,” Said Columbia University’s Arlin Crotts, referring to the ejecta in the vicinity of the star. “This observation shows it is a disk, and it is populated with fast-moving ejecta from previous outbursts.”
Indeed, this discovery raises some exciting possibilities, such as providing researchers with the ability to map the anatomy of previous outbursts from the star as the light echo evolves and illuminates the 3-D interior of the disk like a Chinese lantern. The disk is inclined about 30 degrees to our line of sight, and researchers suggest that the companion star may play a role in the molding of its structure from a sphere into a disk. The disk of material surrounding T Pyxidis is huge, about 1 light year across. This results in an apparent ring diameter of 6 arc seconds (about 1/8th the apparent size of Jupiter at opposition) as seen from our Earthly vantage point.
Paradoxically, light echoes can appear to move at superluminal speeds. This illusion is a result of the geometry of the path that the light takes to reach the observer, crossing similar distances but arriving at different times.
And speaking of distance, measurement of the light echoes has given astronomers another surprise. T Pyxidis is located about 15,500 light years distant, at the higher 10% end of the previous 6,500-16,000 light year estimated range. This means that T Pyxidis is an intrinsically bright object, and its outbursts are even more energetic than thought.
Light echoes have been studied surrounding other novae, but this has been the first time that scientists have been able to map them extensively in 3 dimensions.
“We’ve all seen how light from fireworks shells during the grand finale will light up the smoke and soot from the shells earlier in the show,” said team member Stephen Lawrence of Hofstra University. “In an analogous way, we’re using light from T Pyx’s latest outburst and its propagation at the speed of light to dissect its fireworks displays from decades past.”
Researchers also told Universe Today of the role which amateur astronomers have played in monitoring these outbursts. Only so much “scope time” exists, very little of which can be allocated exclusively to the study of light echoes. Amateurs and members of the American Association of Variable Star Observers (AAVSO) are often the first to alert the pros that an outburst is underway. A famous example of this occurred in 2010, when Florida-based backyard observer Barbara Harris was the first to spot an outburst from recurrent novae U Scorpii.
And although T Pyxidis may now be dormant for the next few decades, there are several other recurrent novae worth continued scrutiny:
Name
Max brightness
Right Ascension
Declination
Last Eruption
Period(years)
U Scorpii
+7.5
16H 22’ 31”
-17° 52’ 43”
2010
10
T Pyxidis
+6.4
9H 04’ 42”
-32° 22’ 48”
2011
20
RS Ophiuchi
+4.8
17H 50’ 13”
-6° 42’ 28”
2006
10-20
T Coronae Borealis
+2.5
15H 59’ 30”
25° 55’ 13”
1946
80?
WZ Sagittae
+7.0
20H 07’ 37”
+17° 42’ 15”
2001
30
Clearly, recurrent novae have a tale to tell us of the role they play in the cosmos. Congrats to Lawrence and team on the discovery… keep an eye out from future fireworks from this rare class of star!