Posted on by VirtualAstro

Night Sky Guide: January 2012

January Sky Northern Hemisphere Credit: Adrian West

[/caption]

January brings us striking views of the night skies! You’ll be able to see well known constellations during the long hours of darkness in the Northern hemisphere, with crisp cold skies. This is an ideal time to get out and look at the wonders of the night sky as there is so much to see for the beginner and seasoned astronomer alike.

You will only need your eyes to see most of the things in this simple guide, but some objects are best seen through binoculars or a small telescope.

So what sights are there in the January night sky and when and where can we see them?

Meteor Showers

Quadrantid Meteor Credit: nasa.gov

As soon as the month starts we receive a welcome treat in the form of the Quadrantid meteor shower on the evening of the 3rd/ morning of the 4th of January.

The Quadrantids can be quite an impressive shower with rates (ZHR) of up to 120 meteors per hour at the showers peak (under perfect conditions) and can sometimes produce rates of up to 200 meteors per hour. The peak is quite narrow lasting only a few hours, with activity either side of the peak being quite weak.

Due to a waxing gibbous moon, the best time to look is after midnight and through the early hours when the moon sets in time for us to see the peak which is 07:20 UT.

The radiant of the Quadrantids (where the meteors radiate from) is in the constellation of Boötes, however many people are mislead in thinking they need to look at the radiant to see the meteors – this is not true. Meteors will come from the radiant, but will appear anywhere in the whole sky at random. You can trace the shooting stars path back to the radiant to confirm if it is a meteor from the meteor shower.

For more information on how to observe and enjoy the Quadrantid meteor shower, visit meteorwatch.org

Planets

Mercury is low down in the southeast before sunrise in the first week of January.

Venus will be shining brightly in the southwest until May and will pass within 1° of Neptune the furthest planet on the 12th and 13th of January. You can see this through binoculars or a small telescope. On the 26th Venus and the Moon can be seen together after sunset.

Venus

On the 5th of January, Earth will be at “Perihelion” its closest point to the Sun.

Mars brightens slightly to -0.5 during January and can be found in the tail of Leo; it can be easily spotted with the naked eye. The red Planet is close to the Moon on the night of the 13th/ 14th January.

Mars

On January 2nd Jupiter and the Moon will be very close to each other with a separation of only 5° with Jupiter just below the Moon. Jupiter will continue to be one of the brightest objects in the sky this month.
Jupiter

Saturn now lies in the constellation of Virgo and follows after just after Mars in Leo.
Saturn

Uranus is just barely visible to the naked eye in the constellation of Pisces and can be easily spotted in binoculars or small telescopes throughout the month. The Moon will pass very close to Uranus on the 27th and will be just 5.5° to the left of the planet.
Uranus

Moon phases

  • First Quarter – 1st and 31st January
  • Full Moon – 9th January
  • Last Quarter – 16th January
  • New Moon – 23rd January

Constellations

Credit: Adrian West

In January the most dominant and one of the best known constellations proudly sits in the south of the sky – Orion the hunter.

Easily distinguishable as a torso of a man with a belt of three stars, a sword, club and shield, Orion acts as the centre piece of the surrounding winter constellations. Orion is viewed upside down in the Northern sky as seen from the Southern hemisphere.

Orion contains some exciting objects and its most famous are the Great Nebula in Orion(M42), which makes up the sword and is easily seen in binoculars or a telescope and bright Betelgeuse, Orion’s bright alpha star (α Orionis). Betelgeuse is a red supergiant many times larger than our Sun; it would engulf everything in our solar system out to the orbit of Jupiter, if the two stars swapped places. Betelgeuse will eventually end its life in a Supernova explosion and some people believe that it may have already exploded and the light hasn’t reached us yet. It would make for a fantastic sight!

The Great Orion Nebula by Patrick Cullis
The Great Orion Nebula. Image Credit: Patrick Cullis

If you draw an imaginary line through the three belt stars of Orion and keep going up and to the right, you will come to a bright orange coloured star – Aldebaran (α Tauri) in the constellation of Taurus.
Pleiades Cluster/ Seven Sisters

Taurus depicts a head of a bull with Aldebaran as its eye with a V shape that creates long horns starting from what we call the Hyades cluster, a V shaped open cluster of stars. If you continue to draw a line through the belt stars of Orion, through Aldebaran and keep going, you will eventually get to one of the gems in Taurus – The Pleiades cluster or Seven Sisters (M45) a stunning cluster of blue and extremely luminous stars and from our vantage point on Earth, the most recognisable cluster with the naked eye. A great object to scan with binoculars. A great object to hunt for with a small telescope is the Crab Nebula (M1) near the end of the lower horn of Taurus.
The Crab Nebula
The Crab Nebula

If you go back to our imaginary line drawn through the belt stars of Orion and draw it in the other direction, to left and below, you will come to the very bright star Sirius (α CMa) – The Dog Star in Canis Major. Sirius is the brightest star in the sky and is only 8.6 light years away, it is the closest star visible to the naked eye after the Sun.

Sirius along with Betelgeuse and Procyon (α CMi) in Canis Minor, form an asterism known as the Winter Triangle.

Directly above Orion and the Winter Triangle are the constellations of Gemini (The Twins), with the two bright stars of Castor and Pollux marking their heads and Auriga the charioteer, with its bright alpha star Capella (α Aur). Auriga is host to M36, M37 and M38 which are globular clusters and easily seen through binoculars or small telescope and Gemini plays host to M35.

M37

Only a few of the objects available to see have been mentioned, so get yourself a good map, Planisphere or star atlas and see what other objects you can track down!

Posted on by VirtualAstro

Top Astronomy Events Coming Up in 2012

Stargazing Credit: http://twitter.com/VirtualAstro

[/caption]

As 2011 is drawing to a close, the festive season is here and many of us are winding down and looking forward to the holidays. But this is a great time to look ahead to 2012 and pencil into our calendar and diaries the top astronomical events we don’t want to miss next year.

2012 is going to be a great year for astronomy observing, with some rare and exciting things taking place and a good outlook with some of the regular annual events.

So what top wonders should we expect to see and what will 2012 bring?

Conjunction of Venus and Jupiter

Venus & Jupiter Conjunction Credit: Anthony Arrigo UtahSkies.org

On March 15th the Planets Venus and Jupiter will be within 3 degrees and very close to each other in the early evening sky. This will be quite a spectacle as both planets are very bright (Venus being the brightest) and the pair will burn brightly together like a pair of alien eyes watching us after the Sun sets.

This conjunction (where planets group close together as seen from Earth) will be a fantastic visual and photographic opportunity, as it’s not often you get the brightest Planets in our Solar System so close together.

Transit of Venus

Transit of Venus Credit: Australian Space Alliance

For many, the transit of Venus is the year’s most anticipated astronomical event and it takes place on June 5th – 6th. The Planet Venus will pass between the Earth and the Sun and you will see Venus (a small black circle) slowly move across, or “transit” the disc of the Sun.

Transits of Venus are very rare and only a few have been witnessed since the dawn of the telescope. Be sure not to miss this very rare event as the next one isn’t visible for over another 100 years from now in 2117 and the next after that is in 2125.

The full transit of Venus in 2012 will be visible in North America, the northwest part of South America, Western Pacific, North East Asia, Japan, Australia and New Zealand. Other parts of the world will see a partial transit such as observers in the UK, who will only be able to see the last part of the transit as the Sun rises.

First contact will be at 22:09 UT and final contact will be at 04:49 UT

Take note! You have to use the right equipment for viewing the Sun, such as eclipse glasses, solar filters, or projection through a telescope. Never ever look directly at the Sun and never look at it through a normal telescope or binoculars – You will be permanently blinded! The transit of Venus will be a very popular event, so contact your local astronomy group and see if they are holding an event to celebrate this rare occasion.

Meteor Showers

Don't Miss the Major 2012 Meteor Showers Credit: Shooting Star Wallpapers

2011 was a poor year for meteor showers due to the presence of a largely illuminated Moon on all of the major showers; this prevented all but the brightest meteors being seen.

In contrast 2012 brings a welcome respite from the glare of the Moon as it gives little or no interference with this year’s major showers. The only other issue left to contend with is the weather, but if you have clear skies on the evenings of these celestial fireworks, you are in for a treat.

  • The Quadrantid Meteor Shower peak is narrow and just before dawn on January 4th this shower is expected to have a peak rate (ZHR) of around 80 meteors per hour.
  • The Perseid Meteor Shower peak is fairly broad with activity increasing on the evenings of the August 9th and 10th with the showers peak on the morning of the 12th. Perseids are the most popular meteor shower of the year as it tends to be warm and the shower has very bright meteors and fireballs, with rates of 100+ an hour at its peak.
  • The Geminid Meteor Shower is probably the best meteor shower of the year with high rates of slow bright meteors. The peak is very broad and rates of 100+ meteors per hour can be seen. The best time to look out for Geminids is on the evenings of the 12th to 14th December, but they can be seen much earlier or later than the peak.

If you want to find out more and enjoy the meteor showers of 2012, why not join in with a meteorwatch and visit meteorwatch.org

Jupiter and the Moon

Occultation of Jupiter by the Moon on July 15th as seen from Southern England Credit: Adrian West

European observers are in for a very rare treat as the Moon briefly hides the planet Jupiter on the morning of July 15th. This “lunar occultation” can be seen from southern England and parts of Europe at approximately 1:50am UT (dependant on location) and the planet re-emerges from the dark lunar limb at approximately 3:10am UT.

This is a great chance to watch this rare and bright event, and it will also be a fantastic imaging opportunity.

Annular Eclipse

Annular Eclipse Credit: Kitt Peak Observatory

American observers will have treat on May 20th with an annular eclipse of the Sun. The eclipse will be visible from many western US states and a partial eclipse visible from most of North America.

Because the Moon’s orbit is not a perfect circle and is slightly elliptical, it moves closer and further away from us slightly in its orbit by 13% and on July 15th it is at its furthest point away from the Earth as it passes in front of the Sun.

Normally the Moon covers the entire disc of the Sun and creates a total solar eclipse, but because the Moon is at its furthest point in its orbit on the 15th, we get an annular eclipse, where we can still see a ring of bright light around the Sun, but we don’t get totality.

The eclipse starts roughly at 6:20pm local time for the Western US states and lasts for four and a half minutes.

As mentioned earlier; never, ever look at the Sun without proper protection such as eclipse glasses or filters for equipment! This can damage your eyes and permanently blind you. This is the same for cameras; the sensitive chips inside can be damaged.

The World Not Ending

End Of The World

Finally we get to December 21st, in which astronomy-minded folks will celebrate the solstice. But in case you haven’t heard, some have prophesied the end of the world, saying the Mayan calendar ends. This has been the subject of much discussion, comedy and media coverage, and it has even been made into films.

Will the Antichrist press the red button and will there be the Rapture? Will the Earth reverse its magnetic poles, or will we get wiped out by a solar flare, rogue comet or asteroid?

Nope, probably not. You can read our entire series which explains why this whole 2012 end-of-the-world craze is complete hokum.

All I know is 2012 is going to be a great year for astronomy with some very interesting, rare events taking place, with many more regular events to see, as well.

I’m sure it’s not going to end.

 

Posted on by Jason Major

Twisting and Eclipsing on the Sun

A filament partially blocks SDO's view of erupting plasma on Dec. 9. (NASA/SDO)


A video posted today by the team at NASA’s Solar Dynamics Observatory shows two recent events on the Sun: a twisting prominence and the “eclipse” of a plasma eruption by the structure of a darker, cooler filament. Most impressive!

From the SDO team:

Over the past 24 hours we have seen some beautiful solar events. None of them have a direct impact on Earth, but they are astonishing to watch. It just shows how an active star our Sun really is… far from boring! 

On December 8, 2011 a twisting prominence eruption occurred on the lower eastern limb. The view through the AIA 304 angstrom filter shows us this beautiful eruption. 

A filament partially blocks SDO's view of erupting plasma on Dec. 9. (NASA/SDO)
In the early hours of December 9, 2011 SDO observed a little bit of a different eclipse. An erupting cloud of plasma was eclipsed by a dark magnetic filament. The eruption is still on the far side of the Sun, behind the eastern limb and is slowly moving forward and over the limb sometime next week. 

In front you can observe the filament of relatively cool dark material floating across the Sun’s surface in the foreground. That filament partially blocks the view of the hot plasma eruption behind it. 

Excellent footage of our constantly-active Sun! It’s easy to forget too that these events and structures are many, many times larger than our entire planet… the sheer power of a star is quite an impressive thing to see. Thanks to SDO we get an unblinking front-row seat to all the action!

See more from SDO on the mission site here.

Thanks to Camilla Corona SDO, the team’s mascot, official spokesbird and all-around “hot chick”!

Posted on by Ray Sanders

Could Solar Storms ‘Sandblast’ the Moon?

Coronal Mass Ejection as viewed by the Solar Dynamics Observatory on June 7, 2011. A similar type of outburst triggered aurorae during a strong geomagnetic storm in February 1872. Image Credit: NASA/SDO
Coronal Mass Ejection as viewed by the Solar Dynamics Observatory on June 7, 2011. A similar type of outburst triggered aurorae during a strong geomagnetic storm in February 1872. Image Credit: NASA/SDO

[/caption]According to a new set of NASA computer simulations, solar storms and Coronal Mass Ejections (CMEs) can erode the lunar surface. Researchers speculate that not only can these phenomena erode the lunar surface, but could also be a cause of atmospheric loss for planets without a global magnetic field, such as Mars.

A team led by Rosemary Killen at NASA’s Goddard Space Flight Center, has written papers exploring different aspects of these phenomena and will appear in an issue of the Journal of Geophysical Research Planets. The team’s research was also presented earlier this week during the fall meeting of the American Geophysical Union.

What are CME’s? Corona Mass Ejections are intense outbursts of the Sun’s usually normal solar wind which consists of electrically charged particles (plasma). CME’s blow outward from the surface of the Sun at speeds in excess of 1.6 million kilometers per hour into space and can contain over a billion tons of plasma in a cloud larger than Earth.

Our Moon has the faintest traces of an atmosphere, which is technically referred to as an exosphere. The lack of any significant atmosphere, combined with the lack of a magnetic field, makes the lunar surface vulnerable to the effects of CME’s.

William Farrell, DREAM (Dynamic Response of the Environment at the Moon) team lead at NASA Goddard, remarked, “We found that when this massive cloud of plasma strikes the Moon, it acts like a sandblaster and easily removes volatile material from the surface. The model predicts 100 to 200 tons of lunar material – the equivalent of 10 dump truck loads – could be stripped off the lunar surface during the typical 2-day passage of a CME.”

While CME’s have been extensively studied, Farrell’s research is the first of its kind that attempts to predict the effects of a CME on the Moon. “Connecting various models together to mimic conditions during solar storms is a major goal of the DREAM project” added Farrell.

When intense heat or radiation is applied to a gas, the electrons can be removed, turning the atoms into ions. This process is referred to as “ionization”, and creates the fourth form of matter, known as plasma. Our Sun’s intense heat and radiation excites gaseous emissions, thus creating a solar wind plasma of charged particles. When plasma ions eject atoms from a surface, the process is called “sputtering”.

The lead author of the research paper Rosemary Killen described this phenomenon: “Sputtering is among the top five processes that create the Moon’s exosphere under normal solar conditions, but our model predicts that during a CME, it becomes the dominant method by far, with up to 50 times the yield of the other methods.”

Images from computer simulations of the lunar calcium exosphere during a CME (left) and the slow solar wind (right). Red and yellow indicate a relatively high abundance of calcium atoms while blue, purple, and black indicate a low abundance. The CME produces a much denser exosphere than the slow solar wind. Image Credit: NASA / Johns Hopkins University

In an effort to better test the team’s predictions, studies will be performed using NASA’s Lunar Atmosphere And Dust Environment Explorer (LADEE). Scheduled to launch in 2013 and orbit the Moon, the team is confident that the strong sputtering effect will send atoms from the lunar surface to LADEE’s orbital altitude (20 to 50 km).

Farrell also added, “This huge CME sputtering effect will make LADEE almost like a surface mineralogy explorer, not because LADEE is on the surface, but because during solar storms surface atoms are blasted up to LADEE.”

Affecting more than just our Moon, solar storms also affect Earth’s magnetic field and are the root cause of the Northern and Southern lights (aurorae). The effect solar storms have on Mars is a bit more significant, due in part to the Red Planet’s lack of a planet-wide magnetic field. It is widely theorized that this lack of a magnetic field allows the solar wind and CME’s to erode the martian atmosphere. In late 2013, NASA will launch the Mars Atmosphere and Volatile Evolution (MAVEN) mission. The goal of MAVEN is to orbit Mars and help researchers better understand how solar activity, including CMEs, affects the atmosphere of the red planet.

Learn more about the DREAM team at: http://ssed.gsfc.nasa.gov/dream/
If you’d like to know more about NASA’s Lunar efforts, visit: http://lunarscience.nasa.gov/

Source: NASA Solar System News

Posted on by Jason Rhian

Voyager 1 Spacecraft Enters New Region of Solar System

The Voyager 1 spacecraft has started to transverse what JPL has dubbed as a "cosmic purgatory" between our solar system - and interstellar space. Image Credit: NASA/JPL

[/caption]

Voyager 1 is in uncharted territory. The long-lived spacecraft has entered a new region of space that lies between where our solar system ends and where interstellar space begins. This area is not a place of sightseeing however, as a NASA press release referred to it as a kind of “cosmic purgatory.”

Here, the solar winds ebb somewhat, the magnetic field increases and charged particles from within our solar system – is leaking out into interstellar space. This data has been compiled from information received from Voyager 1 over the course of the last year.

The Voyager spacecraft's compliment of scientific instruments have provided scientists back on Earth with information about what the space environment at the fringes of our sun's influence is truly like. Image Credit: NASA/JPL - Caltech

“Voyager tells us now that we’re in a stagnation region in the outermost layer of the bubble around our solar system,” said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. “Voyager is showing that what is outside is pushing back. We shouldn’t have long to wait to find out what the space between stars is really like.”

Despite the fact that Voyager 1 is approximately 11 billion miles (18 billion kilometers) distant from the sun – it still has not encounter interstellar space. The information that scientists have gleaned from the Voyager 1 spacecraft indicates that the spacecraft is still located within the heliosphere. The heliosphere is a “bubble” of charged particles that the sun blows around itself and its retinue of planets.

Voyager 1 has traveled far past the realm of the gas or even ice giants and is now in uncharted territory where scientists are learning more and more about the dynamic environment at the far-flung edges of our solar system. Image Credit: NASA/JPL - Caltech

The latest findings were made using Voyager’s Low Energy Charged Particle instrument, Cosmic Ray Subsystem and Magnetometer.

Experts are not certain how long it will take the Voyager 1 spacecraft to finally breach this bubble and head out into interstellar space. Best estimates place the length of time when this could happen anywhere from the next few months – to years. These findings counter findings announced in April of 2010 that showed that Voyager 1 had essentially crossed the heliosphere boundary. The discoveries made during the past year hint that this region of space is far more dynamic than previously thought.

Voyager 1 has entered into a region of space between the sun's influence and the beginning of interstellar space that NASA has dubbed the "stagnation region." Image Credit: NASA/JPL - Caltech

The magnetometer aboard Voyager 1 has picked up an increase in the intensity of the magnetic field located within this “stagnation field.” Essentially the inward pressure from interstellar space is compressing the magnetic field to twice its original density. The spacecraft has also detected a 100-fold increase in the intensity of high-energy electrons diffusing into our solar system from outside – this is yet another indicator that Voyager 1 is approaching the heliosphere.

The interplanetary probe was launched from Cape Canaveral Air Force Station’s Space Launch Complex 41 (SLC-41) on Sept. 5, 1977, Voyager 1’s sister ship, Voyager 2 is also in good health and is about 9 billion miles (15 billion kilometers) from the sun (it too was launched in 1977). The spacecraft itself was built by NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

“Voyager is a mission of discovery and it’s at the edge of the solar system still making discoveries,” said Stone said. “The stagnation is the latest in the whole journey of discovery. We are all excited because we believe it means we’re getting very close to boundary of heliosphere and the entry into interstellar space.”

Both of the Voyager spacecraft were thrust to orbit by the powerful Titan boosters - and both in the same year - 1977. Photo Credit: NASA
Posted on by Jason Major

Black Friday’s Secret Solar Eclipse

Annular solar eclipse observed by the Hinode spacecraft on Jan. 6, 2011. Credit: Hinode/XRT

[/caption]

While many in the U.S. will be recovering from Thanksgiving day meals and looking for ways to stretch their holiday shopping dollars at (hopefully local) retailers’ “Black Friday” sales, the face of the Sun will grow dark as the Moon passes in front of it, casting its shadow over the Earth. But it won’t be visible to American shoppers – or very many people at all, in fact… this eclipse will be hiding in the southern skies above Antarctica!

Visibility of Nov. 25 2011 annular eclipse. NASA GFSC

On Friday, November 25, an annular eclipse will occur, reaching a maximum coverage at 06:20:17 UT of magnitude .905. It will be the largest – and last – partial eclipse of the year.

But its visibility will be limited to the most southern latitudes… outside of the Antarctic continent, only New Zealand, Tasmania and parts of South Africa will have any visibility of the event.

An annular eclipse is similar to a total eclipse, except that the Moon is at a further distance from Earth in its orbit and so does not completely cover the disc of the Sun. Instead a bright ring of sunlight remains visible around the Moon’s silhouette, preventing total darkness.

The next solar eclipse will occur on May 20, 2012. It will also be annular, and even darker than the Black Friday one at a magnitude of .944. It will be visible from China, Japan, the Pacific and Western U.S.

Following that, the main event of 2012 would have to be a total eclipse on November 13, which will be visible from Australia, New Zealand and South America (greatest totality will occur over the South Pacific.) Several sites have already set up group travel events to witness it!

Feeling left out on cosmic occultations? Not to worry… there will be a very visible total lunar eclipse on the night of December 10, 2011 (weather permitting, of course) to viewers across the Northern Hemisphere. The Moon will pass into Earth’s shadow, turning gradually darker in the night sky until it is colored a deep rusty red. It’s a wonderful event to watch, even if not as grandiose as a total eclipse of the Sun.

(Plus it’s completely safe to look at, as opposed to solar eclipses which should never be directly observed without safety lenses or some projection device… for the same reasons that you shouldn’t stare at the Sun normally.)

For a listing of past and future eclipses, both solar and lunar, visit Mr. Eclipse here. And you can read more about the Nov. 25 eclipse on AstroGuyz.com.

 

Posted on by Nancy Atkinson

Activity on the Sun Ramps Up with Monster Prominences; Huge Filament Snaps

A large protuberance on the Sun, from Nov. 13, 2011. Credit: César Cantú, Chilidog Observatory.

[/caption]

A huge wall of plasma rose from the Sun’s southeast limb over the weekend, with what might be one of the biggest prominences seen in many years. César Cantu from Monterrey, Mexico, took the image above, adding an “Earth” for reference of how big this prominence really is. A solar prominence is a large, bright feature extending outward from the Sun’s surface. Prominences are anchored to the Sun’s surface in the photosphere, and can loop hundreds of thousands of kilometers into space.

Leonard Mercer from Malta sent us the image below, saying “I never encountered such a huge prominence since I started imaging the Sun.”

A mosaic of 4 images taken of the Sun on Nov. 13, 2011. Credit: Leonard Mercer.

As large as this prominence is, there was also another even larger feature on the Sun. A filament (which is a prominence that is viewed against the solar disk) on the upper left snakes across the Sun’s surface, stretching more than a million km or about three times the distance between Earth and the Moon.

The video below from the Solar Dynamics Observatory shows the filament intact at first, and then later, from 13:00 to 16:00 UT on November 14, 2011, the filament shoots up from the Sun’s surface and snaps apart.

The SDO team explains that the red-glowing looped material is plasma, a hot gas comprised of electrically charged hydrogen and helium. The prominence plasma flows along a tangled and twisted structure of magnetic fields generated by the Sun’s internal dynamo. An erupting prominence occurs when such a structure becomes unstable and bursts outward, releasing the plasma.

Despite all this activity, there hasn’t been much as far as solar flares, but Spaceweather.com encourages anyone with solar telescopes to monitor developments.

Posted on by Nancy Atkinson

Portraits of Our Sun on 11/11/11 at 11:11 UTC

The Sun captured by NASA's Solar Dynamics Observatory Spacecraft.
The Sun captured by NASA's Solar Dynamics Observatory Spacecraft.

[/caption]

The Solar Dynamics Observatory takes images of the Sun about every 10 seconds, so it easily was able to capture the Sun when the clocks and calendars lined up for a mathematically synchronous readout. Below is another image at the same time in different wavelength.

You can check out what the Sun looks like at anytime of the day or year the the SDO website.

The Sun at 11:11 UTC on 11/11/11 in a different wavelength. Credit: NASA

Posted on by Nancy Atkinson

Astronomy Cast Ep. 238: Solar Activity

sunmass.thumbnail.jpg
The Solar Cycle

The Sun looks like a harmless burning ball of fire in the sky: warm, life-giving and forever unchanging. But we know better, don’t we. It’s really a massive ball of churning hydrogen plasma, encased in twisting magnetic field lines, speckled with sunspots, and constantly disgorging vast plumes of radiation and charged particles. The Sun is very active indeed.

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

“Solar Activity” shownotes on the Astronomy Cast website.

Posted on by Nancy Atkinson

Giant Sunspot Turns to Face the Earth

The full face of the Sun as seen on Nov. 6, 2011, showing AR 1339 and several other sunspots. Credit: Alan Friedman. Click for a stunning larger version.

[/caption]

What has been billed as the largest sunspot observed in several years has now rotated around to stare straight at Earth. How large is it? Active Region 1339 and the group of sunspots adjacent to it extends more than 100,000 km from end to end and each of the several dark cores is larger than Earth. The now very active Sun has already blasted out several medium- to large-sized solar flares and has the potential to hurl out more.

And the Sun is now dotted with several smaller sunspots as well. Above is an amazing image of all this activity, as captured by astrophotographer Alan Friedman. “This has been a glorious week for solar observers!” Friedman said. “Led by large sunspot region AR1339, the sun’s disk is alive with activity… the most dynamic show in many years.”

Take a look below for an incredible closeup of AR1339 taken by Friedman, as well as a movie from the Solar Dynamics Observatory showing the sunspots rotating into view.

Click on the image for a larger version on Friedman’s website, AvertedImagination.com

From all this activity, there may be a good chance for viewing aurorae. On November 9 at around 1330 UT, a magnetic filament in the vicinity of sunspot complex 1342-1343 erupted, producing a M1-class solar flare and hurling a CME into space, which will probably deliver a glancing blow to Earth’s magnetic field on Nov 11 or 12, according to SpaceWeather.com

A portrait of Active Region 1339 in the wavelength of hydrogen alpha light showing the large sunspot group and the maelstrom of chromosphere that surrounds it. Credit Alan Friedman

And here’s an image from astrophotographer Raymond Gilchrist showing a labeled version of all the current sunspots: 1338, 1339, 1340, 1341, 1342, 1343, 1344.

The 'spotty' Sun on Nov. 10, 2011. Credit: Raymond Gilchrist. Click for version on Flickr.

Raymond used a Baader Solar Continuum Filter and Thousand Oaks Full Solar Filter with a Skywatcher 120mm S/T Refractor,
with a Canon 350D, 1/15th Sec Exp. at ISO400. You can see more of his images at his Flickr page.