Posted on by Nancy Atkinson

See the Invisible Sky with Chromoscope

Screenshot of the new Chromoscope online tool.

[/caption]
Unless you’re Superman or a rattlesnake and can see in X-ray or infrared, there are aspects of night sky you are missing out on. These days, the wonderful assortment of telescope and spacecraft data at our disposal allow us to “see” our universe in the different wavelengths which otherwise are invisible to our limited human vision. Now, there is a quick and easy way to take advantage of this data to explore various spectra, and it’s portable, too. At the dotAstronomy Conference today, a group of astronomers have revealed a new online tool: Chromoscope. The site shows the sky in a range of wavelengths, from high-energy gamma rays through to the longest radio waves, and allows users to move easily around the night sky and switch seamlessly between different wavelengths.

“We wanted to see the whole sky in the different wavelengths,” said Stuart Lowe, lead developer of the project, from the University of Manchester. “You can do that with Google Sky and WorldWide Telescope, but we also wanted to have the ability to use it without an internet connection. You can download Chromoscope to a computer and run it on your laptop, or use it during a presentation where you don’t have access to the internet.”

Additionally, the entire platform is small enough that it can be downloaded to a memory stick and shared with others.

A standard, modern, web browser is all that you need to use Chromoscope so there is no need to install any extra software, plugins or learn a new interface. Being platform independent means that whether you use Windows, Mac or Linux, it should still be accessible.

Plus, it is extremely easy to use.

“Chromoscope sheds new light on familiar objects,” said project member Robert Simpson, from Cardiff University, “such as the Orion nebula, our closest stellar nursery. This view of the Universe has been familiar to professional astronomers for a long while, but Chromoscope makes it accessible to everyone.”

This video of how to use Chromoscope was created by Douglas Pierce-Price, one of the attendees at the dotAstronomy conference:

Chromoscope was created using public-domain datasets from a number of all-sky astronomy projects. It has a simple user-interface that lets you easily move around the sky and fade between wavelengths, illustrating the similarities and differences between what is visible at each wavelength.

“This allows people to see the connections between the night sky we see with our own eyes and the sky that astronomers explore in different wavelengths, such as radio and the infrared,” said Lowe.

The project involves data from ROSAT (X-ray), the Digital Sky Survey (optical), IRAS (infrared), WMAP (microwave) and other all-sky astronomical surveys. There are more wavelengths lined up and ready to go in the near future.

Lowe said the most challenging aspect of the project was building the “slippy map” similar to what is used on Google Sky, from the ground up. “The other challenge was compiling all the data in the different wavelengths in a form that we could use and make it interchangeable.”

Check out Chromoscope!

Posted on by Nicholos Wethington

Vatican Astronomer on the Colbert Report

The Colbert Report Mon – Thurs 11:30pm / 10:30c
Gold, Frankincense and Mars – Guy Consolmagno
www.colbertnation.com
Colbert Report Full Episodes Political Humor U.S. Speedskating

The curator of meteorites at the Vatican, Guy Consolmagno, SJ was on the Colbert Report Tuesday to talk about the existence of extraterrestrials with Colbert. Consolmagno is author of a book about astronomy and its relation to the Catholic faith. Of course, Colbert handled the discussion in his own tongue-in-cheek joking manner, but Consolmagno was a good sport. This is just another in a series of public media events illustrating the Vatican’s position on the possibility of alien existence.

The Pope’s chief astronomer, Rev. Jose Gabriel Funes, announced last May that belief in the existence of extraterrestrial life is not in conflict with faith in God. Last month, the Vatican held a 6-day international conference to examine the likelihood of finding extraterrestrials, and discussing the impact such a finding would have on faith in God. During the conference, many scientists presented on the scientific evidence available on the possibility that aliens exist.

Posted on by John Carl Villanueva

How Big is Mars?

Mars

[/caption]Planet Mars’ Olympus Mons holds the record for the tallest known peak in the entire Solar System. Having a height three times taller than Mount Everest’s and a base wide enough to prevent an observer at the base from seeing the top, you would have expected Mars to be on a relatively big planet. But did you know that Mars is much smaller than Earth? So how big is Mars?

The radius of Mars is only about half that of the Earth’s radius; roughly 3,396 km at the equator and 3,376 km at the poles. For comparison, the earth’s equatorial radius is 6,378 km, while its polar radius is 6,357 km.

These radii give Mars a surface area roughly only 28.4% of Earth’s or 144,798,500 km2. The Pacific Ocean is even larger, with an area of roughly 169,200,000 km2.

The dimensions of Mars also gives it a volume approximately equal to 1.6318×1011 km2 and a mass approximately equal to 6.4185×1023 kg. That’s only about 15.1% and 10.7% that of the Earth’s, respectively.

Despite its noticeably smaller size than the Earth, Mars has more majestic geographical features.

For instance, there’s Valles Marineris, a 4,000 km-long and 7 km-deep canyon that spans about one-fifth of the entire planet’s circumference. It is so long that it’s even longer than the length of Europe. If you compare the Grand Canyon to it, Colorado’s pride and joy won’t look so grand anymore.

Want to know how long the Grand Canyon is? 446 km. That’s very long, yes. But that’s only a little over 10% the length of Valles Marineris.

That’s not the only large geographical feature on Mars. Ma’adim Vallis, is another canyon on Mars that’s larger then the Grand Canyon, with a length of 700 km. Then there’s an impact crater that’s been found to be larger than the combined surface area of the continents of Asia, Europe, and Australia.

Now that you know about these extremely majestic geographical features on Mars, the next time someone asks you, “How big is Mars?” you can tell them how it is much smaller than the Earth … but you can also add the salient features that make the Red Planet much more interesting when it comes to a discussion on sizes.

We’ve got more articles about the Planet Mars here on Universe Today. Click on that link or read about interesting facts about the Planet Mars.

There’s more from NASA: “Unmasking the Face on Mars” and “Mars Shoreline Tests: Massifs in the Cydonia Region”

Here are two episodes at Astronomy Cast that you might want to check out as well:
Stellar Roche Limits, Seeing Black Holes, and Water on Mars
The Search for Extraterrestrial Intelligence

Reference:
NASA

Posted on by Jean Tate

Dwarf Star

A comparison of the Sun in its yellow dwarf phase and red giant phase

[/caption]
A dwarf star is a star that is not a giant or supergiant … in other words, a dwarf star is a normal star! Of course, some dwarf stars are much smaller (less massive, have a smaller radius, etc) than normal (or main sequence, not really massive) stars … and these have names, like white dwarf, red dwarf, brown dwarf, and black dwarf. Our very own Sol (the Sun) is a dwarf star … a yellow dwarf.

Looking more closely at this rather confusing class of objects: a dwarf star has a mass of up to about 20 sols, and a luminosity (a.k.a. intrinsic brightness) of up to about 20,000 sols (‘sol’ is a neat unit; it can mean ‘the mass of the Sun’, or ‘the luminosity of the Sun’, or …!). So just about every star is a dwarf star! Why? Because most stars are on the main sequence (which means almost all have luminosities below 20,000 sols), and only a tiny handful of main sequence stars are more massive than 20 sols. In addition, once a star has burned through all its fuel, it becomes a white dwarf (and, one day, a black dwarf), all of which are dwarf stars by this definition.

The most interesting class of dwarf star is, perhaps, the black dwarf star; it’s hardly a star at all (it doesn’t burn any fuel, except, perhaps, deuterium, for a few million years or so).

So why do astronomers have this classification at all? Hitting the history books gives us a clue … back when spectroscopy was getting started, among astronomers – and well before there was any kind of astronomy except that in the optical (or visual) waveband; think the second half of the 19th century – a curious fact about stars was discovered: the spectra of stars with the same colors could still be very different (and when their distances were estimated, these spectral differences were found to track luminosity). So while dwarf stars overwhelmingly dominate, in terms of numbers, the giants (and sub-giants, and supergiants) pretty much rule in terms of what you can see with your unaided vision.

Neatly linking one kind of dwarf (the Sun, as a yellow dwarf) to another (white dwarf) is Universe Today’s The Sun as a White Dwarf. Other Universe Today articles on dwarf stars (not only white dwarfs!) include Astronomers Discover Youngest and Lowest Mass Dwarfs, Brown Dwarfs Form Like Stars, and Observing an Evaporating Extrasolar Planet.

Astronomy Cast’s episode Dwarf Stars has more on this topic.

Posted on by John Carl Villanueva

How Are Rocks Formed?

A'a lava

As a terrestrial planet, Earth is divided into layers based on their chemical and rheological properties. And whereas its interior region – the inner and outer core – are mostly made up of iron and nickel, the mantle and crust are largely composed of silicate rock. The crust and upper mantle are collectively known as the lithosphere, from which the tectonic plates are composed.

It in the lithosphere that rocks are formed and reformed. And depending on the type of rock, the process through which they are created varies. In all, there are three types of rocks: igneous, sedimentary, and metamorphic. Each type of rock has a different origin. Therefore, the question, “How are rocks formed?” begs three distinct answers.

Continue reading “How Are Rocks Formed?”

Posted on by Nicholos Wethington

Stellar Escapees Await Detection

Stars wandering outside the galactic plane of the Milky Way could number in the billions. Image Credit: APOD

[/caption]

The structure of the Universe and the formation of stars from concentrated dust leads them to be clumped into galaxies of all sorts. But adrift between the galaxies may be billions of undiscovered lonely stars. These escaped stars, thrown out of their homes by gravitational interactions, may number in the billions for the Milky Way galaxy alone, and would provide details of historic galactic formations and mergers.

The theory that escaped and wandering stars exist isn’t new, and ejected stars from other galaxies have already been observed (see Hyperfast Star Ejected from the Large Magellanic Cloud). Our Milky Way formed as the result of many mergers with smaller dwarf galaxies, and as a result of these gravitational train wrecks, billions of stars could have been thrown out of the system, breaking free of their gravitational bonds to wander between the galaxies forever.

Wandering stars – those that have loosely bound orbits around a galaxy  – and escaped stars that have left the galaxy altogether could be discovered in the near future by the Large Synoptic Survey Telescope, planned for development in Chile, and Pan-STARRS. In the December 10 issue of Astrophysical Journal Letters, a team of astronomers led by Michael Shara of the American Museum of Natural History explores the provenance of these drifters, and estimates the lower limit of their numbers to be 0.05% of the Milky Way galaxy’s stellar population. That places their numbers well in the billions.

Red giant stars and classical novae have been detected outside the Milky Way, but only in clusters. Finding the individual escaped stars would be a challenge because of how dim they would appear. Because of the mechanism that ejects them  from the Milky Way, many would be older and redder, having formed when the galaxy was much younger. But the phenomenon of novae and supernovae would allow upcoming large scale sky surveys to pick up the few that exploded.

Building up a database of these intergalactic novae and supernovae would give astronomers better information on their orbital characteristics, which in turn would allow for improved modeling of how the Milky Way formed: knowing where the stars are now and what their velocity is gives information as to where they were in the past. Research into older, high-velocity stars that travel back into the Milky Way is ongoing, and would supplement the figure for how many of these galactic jailbreakers exist.

Source: Arxiv, nod to Scientific American

Posted on by Nancy Atkinson

Dot Astronomy in One Word

So, what have I been up to this week at the .Astronomy conference in Leiden, The Netherlands? And just what is .Astronomy? Who better to explain than those in attendance at the world’s largest (and only!) annual conference dedicated to exploring and sharing cutting-edge astronomy and the latest web technology. But trying to explain this wonderful conglomeration of amazing people, innovative ideas and avant-garde technology in just one word is difficult, as you’ll see.

Thanks to conference attendee Markus Poessel who created this video during Wednesday’s “Hack Day,” where everyone shared their talents and latest widgets and gadgets.

Posted on by Nancy Atkinson

Explore the Universe with Science@ESA

ESA Podcast #1 screenshot.

[/caption]

If you’re looking for some superb space and astronomy vodcasts, ESA has produced a series of informative video podcasts that explore our Universe as seen through the “eyes” of ESA’s fleet of science spacecraft. “The Science@ESA podcast series was started as part of an education and public outreach project for the International Year of Astronomy,” said Dr. Salim Ansari, from ESA’s Directorate of Science and Robotic Exploration, “but it will continue on past IYA, continuing to cover more missions and discoveries.”

The series is a high quality video podcast with HD graphics and stunning visuals. Ansari said the production all done in house.

“One of my favorites is actually the first podcast that shows how with our eyes we see just a small portion of the electromagnetic spectrum,” Ansari said. “But we demonstrate how the different spacecraft can provide insight across the whole spectrum.”
ESA podcast screenshot.
Other podcasts delve into specifics of the electromagnetic spectrum that will be explored by the new Planck (microwave) and Herschel (infrared) spacecraft, to learning about the Gaia galaxy mapper mission that will determine the position of a billion stars.

A new 7th podcast will be released next week that introduces the solar system as seen by the Venus Express, Mars Express, Rosetta, Cassini-Huygens, SoHO and Cluster.

See the Science@ESA page for a complete list of podcasts.

Posted on by Nicholos Wethington

The LHC Will Discover the Higgs. Wanna Bet?

Want to bet on whether the Higgs will be discovered? You can. Image Credit: Alexander Unzicker/CERN

[/caption]

If you’re of the opinion that the Large Hadron Collider – which just became the most powerful supercollider ever built by humans on Monday – will ultimately triumph in its quest to find the Higgs boson, you might be able to make a few bucks. If you’re wrong, well, you might lose a few, too. That’s right, along with betting on the elections, Academy Awards, and the snowfall in New York, the discovery of the Higgs boson is a tradeable commodity.

A physics and math lecturer in Munich, Dr. Alexander Unzicker, wants you to place a bet on whether or not the Higgs will be discovered at the LHC at the prediction market site Intrade. You can bet on whether it will be discovered by the end of December 2009, or by the end of each year until 2013, according to your own bravado. The contracts available are based on a $10 scale, so your winnings or losses may be in the single digits range.

According to his site, if you have inside information on the subject, it’s not illegal. So if you work at the LHC and are fairly confident in the positive identification of the Higgs, it might be worth your while.

Unzicker claims inspiration for the idea from Immanuel Kant, who wrote in his most famous work, The Critique of Pure Reason:

The usual test, whether that which any one maintains is merely his persuasion, or his subjective conviction at least, that is, his firm belief, is a bet. It frequently happens that a man delivers his opinions with so much boldness and assurance, that he appears to be under no apprehension as to the possibility of his being in error. The offer of a bet startles him, and makes him pause. Sometimes it turns out that his persuasion may be valued at a ducat, but not at ten. For he does not hesitate, perhaps, to venture a ducat, but if it is proposed to stake ten, he immediately becomes aware of the possibility of his being mistaken–a possibility which has hitherto escaped his observation. If we imagine to ourselves that we have to stake the happiness of our whole life on the truth of any proposition, our judgement drops its air of triumph, we take the alarm, and discover the actual strength of our belief. Thus pragmatical belief has degrees, varying in proportion to the interests at stake.

If you haven’t had the fortune (as have I) of four years studying philosophy, this passage from Kant can be neatly summed up with the old adage, “Put your money where your mouth is.” Stephen Hawking has been in on this game for a while, betting Gordon Kane $100 that the Higgs will not be found by the LHC.

Of course, this isn’t the only betting you can do on matters of scientific import. At Stranieri.com, you can bet on a number of long-term predictions, including whether we will receive communication from intelligent beings outside the solar system in the next 50 years. The bets you make there are long-term (some are for over 200 years into the future), and the money held is used for philanthropic purposes.

From reading his site, it’s evident Unzicker is not of the opinion that the Higgs will be found. Are you? Would you be willing to bet on it? Leave your opinions in the comments.

Source: Physicsworld.com, Unzicker’s site. Kant quote taken from Fullbooks.com

Posted on by Nicholos Wethington

Superbright Supernova First Observed of Antimatter Variety

The supernova 2007bi, circled in the image above, might be the first confirmation of a pair-instability supernova. Image Credit: Nearby Supernova Factory

[/caption]

The supernova 2007bi wasn’t your typical supernova: it was 10 times brighter than a Type Ia supernova, making it one of the most energetic supernova events ever recorded. Astronomers from the University of California Berkeley have analyzed the explosion, which was recorded by a robotic survey in 2007, and found that it is likely the first confirmed observation ever made of a pair-instability supernova, a type of extremely energetic supernova that has been theorized but never directly confirmed.

The confirmed observation of a pair-instability supernova has been long-awaited – the theory that they exist has been around since the 1960’s – but it appears as if the wait is over. The supernova 2007bi, seen by the Nearby Supernova Factory in April of 2007, is the first observed supernova that fits the bill for the unfathomably huge proportions of pair-instability supernovae explosions. A team of astronomers led by Alex Filippenko of the University of California Berkeley published their analysis in in the December 3rd issue of Nature. The discovery was initially made by the Nearby Supernova Factory, and emission spectra of the event was taken with the Keck Telescope and Very Large Telescope in Chile 

These type of supernovae occur only in stars above 100 solar masses, and are incredibly bright. Energetic gamma rays are created by the intense heat in the core of the star. These gamma rays, in turn, create antimatter pairs of electrons and positrons. Because of this antimatter production, the outward pressure exerted by the nuclear reactions in the core of the star is lessened, and gravity takes over, quickly collapsing the massive core of the star and creating a supernova.

There are theorized to be two kinds: those that explode with just enough force to allow for the mass around the leftover core of the star to recombine, and those that explode completely with not a smidgen left to form a black hole or neutron star. The supernova 2006gy, which had a luminosity 10 times that of a Type Ia supernova, is thought to be of the first variety. Here’s our story on that one, Could Antimatter be Powering Super-Luminous Supernovae? and Eta Carinae may also fit the profile.hese types of pair-instability supernovae will eject the outer shells of the star’s matter, settle down into an equilibrium, and repeat that process until the mass is low enough for a normal supernova to occur.

But 2007bi was much too massive to settle back down and explode multiple times. With a mass of 200 suns, the runaway thermonuclear explosion that happened in its core was energetic enough to effectively vaporize the entire star. Pair-instability supernovae in stars above 130 solar masses leave nothing behind in the way of black holes or neutron stars, but because they are so energetic and luminous, the increasing light from the explosion peaks over a very long time – 70 days in the case of 2007bi.

Though the team detected the supernova almost a week after the peak, they were able to calculate the duration of the light curve. They then studied the remnants of the explosion over the next 555 days as it faded away.

Filippenko said, “The central part of the huge star had fused to oxygen near the end of its life, and was very hot. Then the most energetic photons of light turned into electron-positron pairs, robbing the core of pressure and causing it to collapse. This led to a nuclear runaway explosion that created a large amount of radioactive nickel, whose decay energized the ejected gas and kept the supernova visible for a long time.”

The star was unique in another way: it lies in a nearby dwarf galaxy, which contains little else but the elements hydrogen and helium. Because of this, 2007bi is much like the stars that existed near the beginning of the Universe, before the trillions of supernovae populated the Universe with heavier elements. Looking more closely at dwarf galaxies – the Universe has them in spades, but they are quite dim – may be the key to observing more supernovae of this kind. Being able to study its explosion and aftereffects will give scientists a look into what the earliest massive stars acted like.

Source: Berkeley Lab press release