Category: Astronomy

Do you have children or grandchildren? Perhaps a younger brother or sister? Then, there is no greater gift which you can give them than to pass on the love of the starry skies. Right now, one of the easiest constellations to recognize – Orion – is a cinch to find for both the northern and southern hemisphere. Let’s take advantage of the weekend’s early moon-free skies as we take the young folks out to look for Night Lights and practice some astronomy for kids!

To begin learning about our Universe, all you have to do is look up at the night sky. After all, that’s how astronomy began! When humans first began to notice the stars, the saw patterns they could easily remember. These patterns are called asterisms. In ancient times, there was no television or video games – so people began to make up stories about the asterisms they saw in the stars. Just like a game of “connect the dots”, asterisms represented legendary people – or even animals! One of the most famous of all is Orion the Hunter. All the old stories tell that Orion was an excellent hunter whose memory is captured in the stars. If you look above his bow you will see stars of Taurus the Bull and underneath his feet are the stars of Lepus the Rabbit. Both of these asterisms were animals he chased! But no hunter is complete without his faithful hunting dogs. The bright star following behind Orion is Sirius – a star which is part of an asterism that represents a big dog.

As time passed, astronomers began to make maps of the asterisms they recognized and the names on the maps became constellations. The night sky soon began to be filled with constellations and many even shared the same stars! To keep things in an understandable order, a group called the International Astronomical Union made a rule that only 88 asterisms could be called a constellation. This doesn’t mean the stars of a constellation are easy to see or what they are supposed to look like makes sense! Don’t worry if it is harder to see some constellations than others, because what we see here on Earth isn’t how the star patterns would look from a different place in our galaxy.

Now, let’s take an imaginary journey into space…

The asterisms we see in the stars might look close together from our point of view, but if we could fly by them or see them from from another solar system they would all appear very far apart. If we were able to journey past the stars in Orion, we would see they really aren’t even connected to each other – or even close! If you take a look at this illustration you can get an idea of how far apart the stars of Orion really are looking at them from Earth. While they make a pattern in the sky, they are very far apart in space!

If you live in the city, you will probably be able to see many of the stars that make up the constellation of Orion – but if you drive to the country you will be amazed at all the stars you can see with just your eyes. Practice finding Orion the Hunter and see how many of its stars you can see. In just a few weeks, you can take part in a very exciting science study where you will become a Star Hunter!

Although no one likes getting up early, the morning of February 1 will be worth the effort. Just before local dawn, the scene is set as brilliant planets Venus and Jupiter rise together ahead of sunrise. The planetary pair will be so close together they can easily fit in the same binocular field of view and in a low power, wide field telescope eyepiece. Even if you don’t use optical aid, the dazzling duet will capture the eye….

“Your eye is like a digital camera,” explains Dr. Stuart Hiroyasu, O.D., of Bishop, California. “There’s a lens in front to focus the light, and a photo-array behind the lens to capture the image. The photo-array in your eye is called the retina. It’s made of rods and cones, the fleshy organic equivalent of electronic pixels.” Near the center of the retina lies the fovea, a patch of tissue 1.5 millimeters wide where cones are extra-densely packed. “Whatever you see with the fovea, you see in high-definition,” he says. The fovea is critical to reading, driving, watching television. The fovea has the brain’s attention. The field of view of the fovea is only about five degrees wide. On Friday morning, Venus and Jupiter will fit together inside that narrow angle, signaling to the brain, “this is worth watching!”

But Venus and Jupiter aren’t the only pair sparkling the pre-dawn skies. If you look a bit further south, you’ll notice that the waning Moon and Antares are also making a spectacular show! While they will be separated by a little more distance, the red giant and earthshine Moon will still fit within the eye’s fovea – and a binocular field of view!

Where will all the celestial action take place? Look no further than the ecliptic plane – the imaginary path the Sun, Moon and planets take across the sky. For many observers, the ecliptic plane begins low in the southeast – but southern hemisphere viewers have a much different view! But don’t wait until Friday to have a look. If you’re up before dawn, step outside and watch as Venus and Jupiter draw closer together over the next several days and the Moon creeps to the east. On February 3, the Moon will form a line-up with the two planets and a striking triangle on the morning of February 4. Be sure to have a camera on hand and share your photos!

Wishing you clear skies….

Galaxies, like people, tend to stick together. These galaxies collect together into communities large and small, called clusters and even superclusters. According to new research gathered by NASA’s Spitzer Space Telescope, stars seem to form better in the cosmic suburbs of these clusters.

Galaxy clusters can be enormous, locking together thousands of galaxies into a mutual gravitational dance. Seen from afar, these groups of galaxies form large blobs (the clusters) linked together by spider web-like filaments that stretch for millions of light-years. The filaments contain the smaller collections of galaxies working their way towards the largest clusters.

Spitzer’s infrared view revealed two of these filaments in the galaxy cluster Abell 1763. Galaxies are traveling along these filaments, and will eventually collide with the larger cluster itself.

The researchers used Spitzer to measure the rates of star formation in both filaments and the larger galaxy cluster itself. They found that the filaments have much higher rates of star formation than the cluster.

“This is the first time we’ve ever seen a filament leading into a cluster with an infrared telescope,” says Dario Fadda, of the Herschel Science Center, which is located at the California Institute of Technology in Pasadena, California. “Our observations show that the fraction of starburst galaxies in the filaments is more than double the number of starburst galaxies inside the cluster region.”

Upcoming space missions, such as ESA’s Herschel Space Telescope, will take these infrared observations to the next level, watching how filaments and clusters affect the growth of galaxies in greater detail.

Original Source: NASA/Spitzer News Release

Years of work are about to pay off, as Europe’s Large Hadron Collider is almost ready to come online. Soon physicists will be awash in data from the highly energetic particle collisions generated in the facility. But Nature, as usual, already has the upper hand, with a natural particle accelerator capable of pushing particles with 20 times as much energy as the LHC.

ESA’s Integral gamma ray observatory has been watching one of the brightest X-ray regions in the sky, known as the Ophiuchus galaxy cluster. And it’s turned up evidence that the violent region is acting like a natural particle accelerator, pushing electrons to enormous energies.

What kind of environment could create this?

You think the Sun is hot, clocking at a few thousand degrees Kelvin. But the gas in Ophiuchus is more than 100 million degrees Kelvin. Ophiuchus actually contains two galaxies clusters in the process of merging. The violence of this merger sends intense shockwaves rippling through the superheated gas.

The researchers are considering two specific mechanisms for how these X-rays are produced, and are planning follow-up observations to understand it better. In one situation, electrons are caught in the magnetic field threading through the cluster. As they spiral around, they would release the X-ray radiation. In a second scenario, the electrons would actually carry 100,000 times as much energy, and might be colliding with the background microwave radiation in the Universe, left over from the Big Bang.

It’s this X-ray radiation that Integral spotted.

Ophiuchus is able to give particles 20 times as much energy as researcher are hoping to coax out of the Large Hadron Collider.

“Of course the Ophiuchus cluster is somewhat bigger,” says Stéphane Paltani, a member of the team. While LHC is 27 km across, the Ophiuchus galaxy cluster is over two million light-years in diameter.”

Original Source: ESA News Release

Astronomers used to think that brief stellar eruptions called novae generated massive amounts of dust. But new observations of a well known nova system called RS Ophiuchus shows that isn’t the case. The dust was there already, and a nova blast just clears it all away.

The discovery was made using the massive Keck Interferometer, where the two 10-metre (33 feet) Keck telescopes on Hawaii’s Mauna Kea are merged together into a single super-telescope. It’s not like some kind of Japanese anime robot linking together; the telescopes just sit there. All the merging is done behind the scenes, through optics, electronics, and computers.

The Keck Interferometer can null the light coming from a star, revealing its surroundings. This allows the combined instrument to see objects with 10 times more resolving power than a single telescope working alone.

This “nulling mode” is largely used to reveal planet-forming disks of gas and dust surrounding distant stars. With the nuller blocking the starlight, the dimmer disk can be revealed.

In this recent observation, the Keck Interferometer observed a nova in a star surrounded by a dusty disk. The system contains a white dwarf and a red giant. The red giant is shedding its outside layers, while the white dwarf is gobbling it up.

Once a certain amount of matter piles up on the surface of the white dwarf, it explodes in a bright nova. This star has had 5 outburst over the last 100 years, so astronomers knew it would be flaring up again shortly.

The astronomers didn’t see any dust in the inner regions near the star – it was probably vaporized in the explosion. But around 20 times the Earth-sun distance, the researchers did see the dust again.

This flies in the face of what we expected. Astronomers had previously thought that nova explosions actually create dust,” said Richard Barry of Goddard, lead author of the paper on the observations that will appear in the Astrophysical Journal. They were expecting the nova to generate the dust. But instead, the dust was already there, and the nova just illuminated it.

The researchers now think that the dust is created as the star passes through the red giant’s wind, creating a pinwheel pattern around it. The denser regions in this pinwheel are cool enough to stick together to form dust particles. The blast wave from the nova destroys the pinwheel of dust, but it’ll reform again in the next few years.

Ready for another nova blast to blow it all apart again.

Original Source: NASA/JPL News Release

Backyard astronomers the world over in the northern hemisphere are looking forward to the closest approach of Near-Earth Asteroid TU24 on the evening of January 29/30 – but just scanning the skies with a small telescope isn’t going to reveal the small, faint traveler. Like trying to find a single running squirrel in a huge forest, Asteroid TU24 will be on the move and success at spotting the target will only happen if you know in advance when to watch the right trees. Or in this case… the stars!

If you’d like to try your hand at observing Near-Earth Asteroid TU24, begin a little in advance by understanding exactly how bright it’s going to be. For just a period of a few hours, TU24 is expected to brighten to around magnitude 11 – considerably fainter than most star charts list. Since the event won’t be visible to the Southern Hemisphere, let’s begin our “capture” expedition by understanding what magnitude 11 and moving should look like. Your mission? Aim your telescope at Polaris!

Polaris is an excellent choice to learn from not only because there are few bright stars nearby, but because the ones around it will circle it over an extended period of time. Once you’ve located Polaris, take a look in your lower power eyepiece and compare what you see to this generation. No stars shown here are fainter than magnitude 11, so Near Earth Asteroid TU24 will appear much like these fainter stars. Because Polaris will not “move”, come back in an hour and see how the field has changed!

Now, let’s take a look at the general location where Near Earth Asteroid TU24 will pass – the center of this map . As you can see from this chart, if we could see magnitude 11 with just our eyes, Ursa Major would be lost in a forest of stars… And so would our squirrel. We know the asteroid will pass through the center of this area at a certain date and time… But we need to get just a little more specific. In order to spot the squirrel in the forest, it’s going to require some very clear directions as to what trees to watch when it passes by. A good place to begin is to visit this link to JPL/NASA’s New Horizons system to generate coordinates called an ephemerides. Because the squirrel would appear in a slightly different position relative to the tree’s branches depending on your position, you need to take extra care when using the New Horizons generator to be specific about your location and remember the information it supplies is expressed in universal time. For example, the starry background at local midnight for London, England would be totally different than the skies seen at local midnight for Palomar Observatory in southern California! We might be looking at the right tree, but to see the squirrel we need to know exactly what branches it is going to be passing by.

When the ephemerides is generated specifically for your location, there will be a long list of numbers that can be confusing if you are first learning astronomy. For those with “Go To” telescopes, it will be as easy as entering the coordinates that are supplied. For example, if we were to observe from Palomar Observatory, we’d put Right Ascension 10 00 50.64 and Declination +64 58 12.5 into the telescope’s system to observe the asteroid at midnight universal time. For those familiar with star charts, the same holds true – use the RA and Dec to pinpoint which star field you need to observe as the asteroid passes. For those who have neither, try visiting at site which will create maps for you, such as Your Sky. Using the “aim virtual telescope” feature, enter the coordinates that New Horizons provides for your location, then customize the chart to your specific needs. Now you know what tree to watch in the forest, what branch, what time the squirrel will pass and how bright he’ll be… But what will he look like?

Using our Palomar example once again, take a look at this photographic plate of the region. Thanks to parallax, Near Earth Asteroid TU24 will move quietly and purposefully across a starry field that will look just like this. It is possible at first glance to find what “star” doesn’t belong in the picture, but watching the field for a length of time will reveal movement – possibly even passing over (occulting) a field star and causing the background star to dim. Scientists will use information like this to help determine the exact size and shape of Asteroid TU24, but we’ll be happy if we just manage to spot the squirrel!

Be sure to dress warmly, and prepare yourself to take notes if at all possible. If an occultation occurs, note the time and duration. The more eyes we have on the skies, the better our chances will be of understanding visitors like Near Earth Asteroid TU24. Objects like these pass by frequently and by educating ourselves and others we make the natural (and safe) mechanics of our galaxy more understood to others! Good luck…

Greetings, Fellow SkyWatchers!

Have you missed me? All you have to do is take a look around the web for the retailer of your choice and you’ll find The Night Sky Companion. Thanks to the great folks at Springer Press (and Sir Patrick Moore), this incredible 674 page, full-color glossy book filled with astronomy pictures, astronomy history, sky watching tips and daily information is only a page away…

The Night Sky Companion takes a look at astronomy every day over the course of the year – offering an overview of general history, soft science, astronomical trivia, and observing guides and motivation. Designed to appeal to readers at all skill levels and involvement, it provides a digest for sky watchers interested in all-in-one-place information that includes history, current events, and of course interesting objects to be observed on any given day. The Moon is followed through its phases with observing instructions, annotated pictorial maps, concise photos, and the science and history of what makes lunar observing a fascinating challenge. Unaided eye observers are offered an opportunity to view many objects or events; learn about their history, science and how just “looking up” can be rewarding. Binocular and small telescope users will find a wealth of things to view using simple star hop instructions and finder charts. This book is more than just an observing guide, it’s a way of learning your way round the night sky. Large-aperture telescope users looking for a challenge are not ignored either. Some of the finest deep-sky objects are detailed, with finder maps and photographs, most of them taken by talented amateurs. Be it a meteor shower, double stars, variable stars, solar viewing, lunar features, a variety of catalog studies, history or the physics and science behind the stars – you’ll find it here, written in an easy-going style ideal for ‘dipping in’ on the relevant day, or even reading from cover to cover.

For those of you who support “Universe Today” through your amazon.com account, I heartily urge you to pick up your own copy here! Go ahead… Search inside! You’re going to love it, and look for even more books to be available soon… 😉

What’s the only thing more exciting than to have a book in the Sir Patrick Moore Series? Having Sir Patrick Moore approve of the book in person! Take a look as one of the photographer’s for The Night Sky Companion – Roger Warner – joins one of England’s land mark astronomers for an evening of observing. What a thrill!

I’ve very much missed my friends here at UT and I’m very happy to announce that in the weeks to come you’ll see my return with new material – from astronomy for kids to challenging telescope objects. It has long been a goal of mine to help others learn the way I did… Through practice, patience and persistence! Please feel welcome to give any suggestions you might have for future editions. I am always more than happy to share what I’ve learned – with you!

Light Speed,

~Tammy

You weren’t imagining things, 2007 really was an unseasonably hot year. In fact, it was tied with 1998 for the second hottest year on record. All in all, the 8 warmest years have all occurred since 1998, and the 14 warmest years since 1990. This mini-record was announced by NASA climatologists this week.

Researchers from NASA’s Goddard Institute for Space Studies used temperature data from weather stations on land, satellite measurements of sea ice temperatures since 1982 and data from ships for earlier years.

“As we predicted last year, 2007 was warmer than 2006, continuing the strong warming trend of the past 30 years that has been confidently attributed to the effect of increasing human-made greenhouse gases,” said James Hansen, director of NASA GISS.

Perhaps the most warming occurred up in the Arctic and high latitude regions of the planet, where vast regions of ice melted away. In fact, the Northwest Passage opened up for the first time, and scientists are predicting that the region could be ice free in the Summer in less than a decade.

The lower ice levels in the Arctic provides more open water and reduces the amount of sunlight reflected back into space. This is expected to increase the rate of warming.

Let’s hope 2008 isn’t so hot.

Original Source: NASA News Release