Dwarf Nova QZ Virginis - Annotated - Image Credit: Dr. Joe Brimacombe
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For all of you variable star fans, there’s a new kid on the block – Dwarf Nova QZ Virginis. It was originally discovered by T. Meshkova on Moscow photographic plates in 1944 and had a magnitude range of 12.9 to as little as 14.5 But what is it? Try a cataclysmic variable star – one that our good friends down under caught just for Universe Today readers!
According to recently released AAVSO Special Notice #144, dwarf nova QZ Vir (once known as T Leo) is currently in outburst, and it appears that this outburst is a supermaximum. Says M. Templeton, “The most recent visual estimate of QZ Vir puts the star at visual magnitude 10.2 (JD 2454857.6201; W. Kriebel, Walkenstetten, Germany). Time series photometry by W. Stein (New Mexico, United States) on 2009 Jan 25 indicates the presence of superhumps in the light curve. Observations by P. Schmeer (Saarburecken-Bischmisheim, Germany), E. Morelle (Lauwin-Planque, France), ASAS-3 (Pojmanski 2002, AcA52, 397) and R. Stubbings (Tetoora Road, Vic., Australia) published on VSNET. (T. Kato; vsnet-alert 10980) suggest QZ Vir may have had a short precursor outburst lasting 2-3 days and fading immediately before the rise to supermaximum. All observations, including both visual estimates and CCD time-series photometry, are strongly encouraged at this time.”
Of course, it didn’t take a lot of encouragement – only some clear skies to get astrophotographer and serious researcher Joe Brimacombe of Southern Galactic to set his telescope towards QZ Virginis and image for us. All we needed to do was provide the following coordinates:
RA: 11 38 26.80 , Dec: +03 22 07.0
Dwarf Nova QZ Virginis - Image Credit: Dr. Joe BrimacombeAs you can see, learning proper stellar coordinates is essential to practicing astronomy. Without them, a stellar field is simply a stellar field as it would be next to impossible to distinguish one background star from the next. While some of us understand what these strange sets of numbers mean – maybe some of our readers don’t. Let’s take just a moment out from our busy days and learn, shall we?
RA stands for Right Ascension. It is the celestial equivalent of terrestrial longitude. RA’s zero point is the Prime Meridian, located in the constellation of Aries where the Sun crosses the celestial equator at the March equinox. Each set of numbers is then measured eastward in three sets – hours, minutes, and seconds, with 24 hours being equivalent to a full circle. Declination, or “Dec” is comparable to latitude, projected onto the celestial sphere, and is measured in degrees north and south of the celestial equator. Points north of the celestial equator have positive declinations, while those to the south have negative declinations. These are also measured in three sets of numbers – degrees, minutes, and seconds of arc.
Now that you know, how do you use them? Chances are, if you have a telescope that has an equatorial mount, you already have the tools in your hands – called “setting circles”. These same sets of numbers are waiting right on your telescope for you to set them! Once your telescope is accurately polar aligned, you just use the setting circles to dial in these numbers and you’ll be right in the approximate area. For those with electronic setting circles, it’s just a matter of inputting the correct coordinates and comparing star fields. Once the general area is found, you simply need to understand how big the field your eyepiece gives and compare it to a star chart – like this one supplied by the AAVSO for QZ Vir.
AAVSO Locator Chart for QZ Vir
Make note of your observations and compare the suspect nova to other stars of known magnitude nearby. When you’re done – don’t keep your observations to yourself! Please report all observations to the AAVSO using the name “QZ Vir” and contribute!
A plaque attached to the side of the remains of pad 34. A solemn reminder of a black day in space history.
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As we go through our busy, every day lives, we scan the headlines in search of news. We pick up this story and that one, filing it away as part of who we are and what has happened in the world. Once in a great while we might take it back out and look at it again, but all too often we tend to forget as time goes on. Let’s change that today…
The era in which I grew up in worshipped astronauts as heroes. We didn’t see it as just another speciality job – or just another routine mission. These men, and eventually women, became larger than life. Human beings willing to take risks above and beyond the ordinary to expand our knowledge and our capabilities as a species. While we sit here comfy and cosy at our desks reading the daily space news, they orbit high above the Earth. Where we once took our daily drive to our factory jobs, they climbed inside experimental spacecraft. When the school bus drops our children off, the teachers go home to their every day lives, too. But not all of them, my friends…
Dave Reneke reminds us that the astronauts paid the ultimate price.
“As fate would have it, the tragedies that killed three Apollo astronauts and two space shuttle crews have anniversaries less than a week apart. Apollo 1 on January 27, 1967, Challenger on January 28, 1986, and Columbia on February 1, 2003. The first manned Apollo mission, Apollo 1, was scheduled for launch on 21 February 1967 at Cape Kennedy’s pad 34. Commander Gus Grissom, Ed White and Roger Chaffee were the flight crew. NASA, preparing for a future moon landing, knew this shakedown flight was a big step in that direction. Engineers, ground personnel and flight controllers were eager for this bird to fly.
Apollo 1 Crew. Ed White, Gus Grissom and Roger Chaffee.All checks had been made and confidence was high – however, Apollo 1 was an accident waiting to happen. A few weeks before launch the crew were 5 1/2 hours into a simulated countdown on 27 January 1967 at the Kennedy Space Centre when White cried, “Fire!” Chafee shouted, “We’re burning up.” In the oxygen-saturated cabin 70 metres in the air atop the Saturn IB rocket at Pad 34, White’s hand was seen trying to blow the hatch. It wouldn’t budge. “If White couldn’t get that hatch off, no one could,” astronaut Frank Borman said later.
Astronauts and their loved ones were in shock. Test pilots died while in the air, no one at NASA had prepared them for an accident on the ground. One of the original Mercury-7 astronauts of 1959, Grissom was 40 years old on the day of the Apollo 1 fire. White at 36 years of age had been pilot for the Gemini 4 mission during which he became the first American to walk in space. Selected as an astronaut in 1963, Chaffee was training for his first spaceflight. He was just 31 years of age.
An investigation later revealed major flaws in almost all aspects of the Apollo capsule’s design and construction. Investigators attributed a chafed wire underneath Grissom’s seat as sparking the inferno. With a great whoosh, like the sound of an oven being lit, the pure O2 in the cabin made every combustible item in the ship burn with super intensity. At the same time, no oxygen was left to breathe. The three astronauts were trapped in their melted suit material, fused with the charred nylon from the inside of the spacecraft. To remove the hatch, five rescuers struggled in thick smoke, each forced to make several trips in order to reach breathable air. Nothing could be done, it was simply too late!
Astronaut Frank Borman, a member of the investigating team, listened to the tape of his friends’ screams and felt himself becoming increasingly angrier with every cry for help he heard. Everywhere he and the rest of the investigation committee looked, they found sloppy workmanship by both the contractor and by NASA. Borman decided that he was going to do whatever it took to make sure the Apollo spacecraft flew again. And when it did, it would be the safest spacecraft ever built.
All that remains of the original Pad 34 complex where Ed White, Gus Grissom and Roger Chaffee lost their lives in a pad fire in 1967. Image credit Dave Reneke As a result, NASA abandoned the oxygen-rich atmosphere. More than 2,500 different items were removed and replaced with non-flammable materials. Engineers redesigned the hatch to open in 10 seconds compared to 90 seconds for the original. Borman, in his book ‘Countdown,’, described each NASA staff member who suffered depression, guilt or a breakdown as a “victim of Pad 34.” One NASA official drove onto a Houston expressway and raced his car at speeds of more than 160 kilometres an hour until the engine caught fire. Others dealt with it in their own way. The final ‘victim’ was White’s wife. She committed suicide in 1984.
NASA’s faster, better, cheaper policy had started to unravel, at the cost of human life – but a far more serious event was about to unfold as we built even bigger, more complex launch vehicles.
Space Shuttle Challenger seconds before it exploded killing all seven crew on board.The Space Shuttle Challenger Disaster took place on the morning of January 28, 1986, when Challenger broke apart 73 seconds into its flight. The New York Times declared the first space shuttle explosion the “worst disaster in space history.” It killed seven astronauts, including the first teacher in space, Christa McAuliffe. She was selected by NASA from more than 11,000 applicants and was scheduled to teach two lessons from Space Shuttle Challenger in orbit. McAuliffe’s third-grade son Scott along with her parents were just some of the thousands of people watching in wonder, then horror that morning as the ship blew apart high in the air.
Challenger Crew - The crew of STS-51-L: Front row from left, Mike Smith, Dick Scobee, Ron McNair. Back row from left, Ellison Onizuka, Christa McAuliffe, Greg Jarvis, Judith Resnik.Some believe the crew died instantly, others believe the capsule remained intact long enough as it was falling for them to realize their fate. We’ll never know. In the aftermath of the disaster, NASA was criticized for its lack of openness with the press. Shuttle flights were suspended pending an investigation, but NASA personnel still believed in the program and wanted it to continue. After a lengthy hiatus, Shuttles eventually flew again, but disaster was to strike one more time, and it came on the morning of February 1, 2003.
A single film frame of the Space Shuttle Columbia Breaking over Texas on February 1, 2003. The Space Shuttle Columbia disintegrated over Texas during re-entry into the Earth’s atmosphere, again killing all seven crew members. The loss of the spacecraft was a result of damage sustained during launch when a piece of foam insulation the size of a small briefcase hit the main propellant tank at launch, damaging the Shuttle’s tiles protecting it from the heat of re-entry. While Columbia was still in orbit, some engineers suspected damage, but NASA managers limited the investigation on the grounds that any risks were ‘acceptable.’
Coumbia Crew - On February 1, 2003, after a 16-day scientific mission, space shuttle Columbia disintegrated during its reentry into the Earth's atmosphere, killing astronauts Rick Husband, William McCool, Michael Anderson, David Brown, Kalpana Chawla, Laurel Clark, and the first Israeli astronaut in space, Ilan Ramon.Columbia was 16 minutes from home when the 2,500 degree heat of re-entry entered the cracked left hand wing and melted the aluminium struts. It exploded 70,000 metres over Texas. “The Columbia is lost. There are no survivors,” President George Bush told the nation.
Evelyn Husband giving a stirring speech at a remembrance ceremony at Kennedy Space Centre in February 2008. Image credit Dave RenekeOne year ago this week I flew to the USA and attended a memorial ceremony at the Kennedy Space Centre for the crew of Columbia. Among the invited guess was Evelyn Husband, wife of the shuttles’ Commander Rick Husband, who had previously piloted the first shuttle mission to dock with the International Space Station. In a stirring speech, and after all she’s been through, Evelyn expressed her earnest hope that the space program would go on. Let’s hope it does. This, they say, is the price of progress. ”
I would personally like to thank Dave Reneke for sharing his remembrance with us. As I sit here writing this story, I look around my office. Each and every wall bears a testimony of its own to the heroes of space – from pictures of mission launches and spacesuits – right down to a display of mission patches and model rockets. These heroes, be it Yuri Gagarin or Neil Armstrong, had a significant impact on my life and what I am today… Just as they may have had an impact on yours. Take the time to remember…
The planet HD80606b glows orange from its own heat in this computer-generated image. A massive storm has formed in response to the pulse of heat delivered during the planet's close swing past its star. The blue crescent is reflected light from the star. Image by D. Kasen, J. Langton, and G. Laughlin (UCSC).
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As mentioned in a previous article today about global warming, we on Earth worry about our planet’s atmosphere rising by a few degrees on average over the next century. But imagine living on a planet where temperatures could rise 700 degrees in just a few hours! A distant planet known as HD80606b, is a gas giant orbiting a star 200 light-years from Earth. It’s extremely eccentric orbit around the star takes it from a relatively comfortable distance in an Earth-like habitable zone to the blazing hot regions much closer than Mercury is to our Sun. Infrared sensors aboard NASA’s Spitzer Space Telescope measured the planet’s temperature as it swooped close to the star, observing a planetary heat wave that rose from 800 to 1,500 degrees Kelvin (980 to 2,240 degrees Fahrenheit) in just six hours. Wow!
And for those readers who like to complain about artist impressions images, the image here is a novel type of “photorealistic” image, created by a new computer program that calculates the radiative transfer processes in astrophysics.
“We can’t get a direct image of the planet, but we can deduce what it would look like if you were there. The ability to go beyond an artist’s interpretation and do realistic simulations of what you would actually see is very exciting,” said Gregory Laughlin, professor of astronomy and astrophysics at UCSC. Laughlin is lead author of a new report on the findings published this week in Nature.
“This is the first time that we’ve detected weather changes in real time on a planet outside our solar system,” said Laughlin “The results are very exciting because they give us important clues to the atmospheric properties of the planet.”
Spitzer observed the planet for 30 hours before, during, and just after its closest approach to the star. The planet passed behind the star (an event called a secondary eclipse) just before the moment of its closest approach. This was a lucky break for Laughlin and his colleagues, who had not known that would happen when they planned the observation. The secondary eclipse allowed them to get accurate measurements from just the star and thereby determine exact temperatures for the planet.
HD80606b has an estimated mass of about four times that of Jupiter and completes its orbit in about 111 days. At its closest approach to the star it experiences radiation about 800 times stronger than when it is most distant.
At the closest point, the sunlight beating down on the planet is 825 times stronger than the irradiation it receives at its farthest point from the star. “If you could float above the clouds of this planet, you’d see its sun growing larger and larger at faster and faster rates, increasing in brightness by almost a factor of 1,000,” Laughlin said.
“Even after finding nearly 200 planets, the diversity and oddness of these new worlds continues to amaze and confound me,” says Paul Butler of the Carnegie Institution for Science’s Department of Terrestrial Magnetism. Butler made the precision velocity measurements of the host star that allowed the planet’s orbit to be calculated. Butler’s work has uncovered about half of the known extra-solar planets.
Daniel Kasen, a Hubble postdoctoral fellow at UCSC, was able to generate the image with the new program. “It calculates the color and intensity of light coming from the glowing planet, and also how starlight would reflect off the surface of the planet,” Kasen said.
The resulting image shows a thin blue crescent of reflected starlight framing the night side of the planet, which glows cherry red from its own heat, like coals in a fire. “These images are far more realistic than anything that’s been done before for extrasolar planets,” Laughlin said.
The planet is expected to pass in front of its star when viewed from Earth on February, and the team will be watching again.
Centaurus A. Credit: ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R.Kraft et al. (X-ray)
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There are some interesting dynamics going on with Centaurus A, an elliptical galaxy about 13 million light-years away. This is a very active and luminous region of space and a great disturbance is going on as another spiral galaxy is trying to get in on the action by merging with Centaurus A. But astronomers now have new insight on what causing all the ruckus: a supermassive black hole at the core of Centaurus A. Jets and lobes emanating from the central black hole have been imaged at submillimeter wavelengths for the first time by using the 12-meter Atacama Pathfinder Experiment (APEX) telescope in Chile. By using a combination of visible and X-ray wavelengths, astronomers were able to produce this striking new image. Help me APEX, you are our only hope!
Centaurus A (NGC 5128) is one of our closest galactic neighbors, and is located in the southern constellation of Centaurus. The supermassive black hole is the source of the force: strong radio and X-ray emissions. Visible in the image is a dust ring encircling the giant galaxy, and the fast-moving radio jets ejected from the galaxy center. In submillimeter light, the heat glow from the central dust disc can be seen and also the emission from the central radio source.
APEX was also able to discern – for the first time in the submillimeter – the inner radio lobes north and south of the disc. Measurements of this emission, which occurs when fast-moving electrons spiral around the lines of a magnetic field, reveal that the material in the jet is travelling at approximately half the speed of light. In the X-ray emission, we see the jets emerging from the centre of Centaurus A and, to the lower right of the galaxy, the glow where the expanding lobe collides with the surrounding gas, creating a shockwave.
A new paper published by a leading researcher says many effects of climate change are already irreversible. Susan Solomon, a leader of the International Panel on Climate Change and a scientist with National Oceanic and Atmopheric Association (NOAA) said even if carbon emissions were stopped, temperatures around the globe will remain high until at least the year 3000. And if we continue with our current carbon dioxide emissions for just a few more decades, we could see permanent “dust bowl” conditions.
Solomon defined “irreversible” as change that would remain for 1,000 years even if humans stopped adding carbon to the atmosphere immediately. As carbon dioxide emissions rise, the planet will be undergo more and more long term environmental disruptions which will persist even if and when emission are brought under control.
The report says temperatures around the globe have risen and changes in rainfall patterns have been observed in areas around the Mediterranean, southern Africa and southwestern North America. Warmer climate also is causing expansion of the ocean, and that is expected to increase with the melting of ice on Greenland and Antarctica.
A recent NASA article said observations have confirmed rising temperatures in Antarctica over the past 50 years in not only the Antarctic Peninsula, but in western Antarctica as well.
In a teleconference, Soloman said this is not just another pollution problem. “We’re used to pollution problems being something we can fix, smog, — we can cut back and things will get better later. Or haze, we think it will go away pretty quickly.”
This is true for gases like methane and nitrous oxide, but not for CO2. “People have imagined that if we stopped emitting carbon dioxide that the climate would go back to normal in 100 years or 200 years,” said Solomon. “What we’re showing here is that’s not right. It’s essentially an irreversible change that will last for more than a thousand years.”
This is because the oceans are currently soaking up a lot of the planet’s excess heat, as well as some of the carbon dioxide from the atmosphere. The carbon dioxide and heat will eventually start coming out of the ocean. And that will take place for many hundreds of years.
The scientists say that once the global thermostat once it has been turned up, its extremely difficult to turn it back down.
Solomon said sea level rise is a much slower thing to happen, that it will take a long time, but we will lock into it based on the peak level of C02 we reach this century.
So, should we just give up? Are we doomed? “It seems like this is even more reason to do something about it,” Solomon said. “When you are committing to something you can’t back out of, you need to proceed even more carefully than when it’s something you can reverse….I don’t think that the very long time scale of the persistence of these effects has been understood.”
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The folks who run the Hubble Space Telescope have decided to ask for some help in choosing where to next point the world’s most famous telescope. People from around the planet can vote to select the next object the Hubble Space Telescope will view. The choices are six objects Hubble has never observed before. You can also enter a drawing to win one of 100 new Hubble pictures of the object that is chosen. The winning image will be released between April 2 and 5, during the IYA’s 100 Hours of Astronomy, a global astronomy event geared toward encouraging as many people as possible to experience the night sky. You need to vote by March 1 to swing Hubble toward your favorite target. So get over to the HubbleSite and vote!
The choices are two planetary nebulae (NGC 40 and NGC 6072), an emission nebula (NGC 6634), an edge-on spiral (NGC 4289), a spiral galaxy (NGC 5172 – seen above from the Sloan Digital Sky Survey) and interacting galaxies (Arp 274). The choices (image stolen from the Bad Astronomer)
Here’s a screen shot of the HubbleSite page where the voting is taking place, with the rankings blurred out. (This image was stolen from Phil Plait’s Bad Astronomy site –thanks Phil!) But get over to the HubbleSite already and vote! If you need some more info to help you decide, there is a video with Dr. Frank Summers, a very fun astronomer-type guy who will explain each of the target objects. This event is part of the International Year of Astronomy (IYA), the celebration of the 400th anniversary of Galileo’s astronomical observations with his telescope.
Inaugeration photo. Credit: White House photo by Paul Morse
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If you’ve been oohing over CNN’s “The Moment” “photo-synth” image of last week’s presidential inauguration, there’s another version that might be even better because you don’t have to download Microsoft’s bulky Silverlight software to see it. And you can thank NASA and the Mars Exploration Rovers for it, too. NASA spinoff technology from the rovers’ cameras was used to create a “Gigapan” image from the festivities at the U.S. Capitol on Jan. 20. Photographer David Bergman used the Gigapan camera system to generate one huge image from a combination of 220 images,with an overall size of 1,474 megapixels. This is the same technology used to create the panoramic images of Mars from the rovers.
Explore the Gigapan image from Jan. 20.
You can zoom, pan, and go anywhere in the image.
More about the technology:
The Gigapan system is a NASA spinoff technology that can capture thousands of digital images and weave them into a uniform high-resolution picture of more than a billion pixels. The technology is the product of a two-year collaboration between NASA and Carnegie Mellon called the Global Connection Project. The Mars rovers Spirit and Opportunity have used the Gigapan system to explore the Red Planet for more than five years.
The rover Pancams take small, 1 megapixel (1 million pixel) digital photographs, which are stitched together into large panoramas that sometimes measure 4 by 24 megapixels. The Pancam software performs some image correction and stitching after the photographs are transmitted back to Earth. Different lens filters and a spectrometer also assist scientists in their analyses of infrared radiation from the objects in the photographs. These photographs from Mars spurred developers to begin thinking in terms of larger and higher quality images: super-sized digital pictures, or gigapixels, which are images composed of 1 billion or more pixels. Panoramic image from the Opportunity Rover. Credit: NASA/JPL/Cornell
Gigapixel images are more than 200 times the size captured by today’s standard digital camera, around 4 megapixels. Although originally created for the Mars missions, the detail provided by these large photographs allows for many purposes, not all of which are limited to extraterrestrial photography.
People on Earth can use it, too, and the Gigapan website is available for anyone to use and upload their pictures. Many users of Gigapan have uploaded standard panorama photographs, as well (although the site suggests photographs be at least 50 megabytes). This is just fine with the Gigapan and the Global Connection Project coordinators, whose aim is simply to encourage exploration and understanding of the various cultures in our world. Visit the Gigapan site for more information.
Neutron stars are formed when large stars run out of fuel and collapse. To get a neutron star, you need to have star that’s larger than about 1.5 solar masses and less than 5 times the mass of the Sun.
If you have less than 1.5 solar masses, you don’t have enough material and gravity to compress the object down enough. You only get a white dwarf. This is what will happen to our own Sun one day.
If you have more than 5 times the mass of the Sun, your star will end up as a black hole.
But if your star is right in between those masses, you get a neutron star.
The neutron star is formed when the star runs out of fuel and collapses inward on itself. The protons and electrons of atoms are forced together into neutrons. Since the star still has a lot of gravity, any additional material falling into the neutron star is super-accelerated by the gravity and turned into identical neutron material.
Just one teaspoon of a neutron star would have the mass of over 5 x 1012 kilograms.
A neutron star actually has different layers. Astronomers think there’s an outer shell of atomic nuclei with electrons about 1 meter thick. Below this crust, you get nuclei with increasing numbers of neutrons. These would decay quickly on Earth, but the intense pressure of the gravity keeps them stable.
When neutron stars form, they maintain the momentum of the entire star, but now they’re just a few kilometers across. This causes them to spin at tremendous rates, sometimes as fast as hundreds of times a second.
We have written many articles about stars on Universe Today. Here’s an article about a neutron star with a tail like a comet, and here’s an article about a a shooting star.
A shooting star is another name for a meteoroid that burns up as it passes through the Earth’s atmosphere. So, a shooting star isn’t a star at all.
Most of the shooting stars that we can see are known as meteoroids. These are objects as small as a piece of sand, and as large as a boulder. Smaller than a piece of sand, and astronomers call them interplanetary dust. If they’re larger than a boulder, astronomers call them asteroids.
A meteoroid becomes a meteor when it strikes the atmosphere and leaves a bright tail behind it. The bright line that we see in the sky is caused by the ram pressure of the meteoroid. It’s not actually caused by friction, as most people think.
When a meteoroid is larger, the streak in the sky is called a fireball or bolide. These can be bright, and leave a streak in the sky that can last for more than a minute. Some are so large they even make crackling noises as they pass through the atmosphere.
If any portion of the meteoroid actually survives its passage through the atmosphere, astronomers call them meteorites.
Some of the brightest and most popular meteor showers are the Leonids, the Geminids, and the Perseids. With some of these showers, you can see more than one meteor (or shooting star) each minute.
An annular solar eclipse earlier today was visible in South-East Asia, southern Africa and Australia. Thanks to M.R. Taufik from Bontang, Indonesia for sharing this image of a complete ring or annulus of light from the sun peeking out from around the moon. Because the moon’s orbit is elliptical, its distance from Earth–and its apparent size—varies. Annular eclipses happen when the moon looks too small to completely cover the sun. Such an event that occurs about 66 times a century.
Image showing the region where the eclipse was visible. Credit: NASA
