Virtual Star Party – February 16, 2014: Fighting Crime while Transiting Jupiter!

Hosts: Fraser Cain & Scott Lewis

Astronomers: David Dickinson, Gary Gonella, James McGee, Tom Nathe, Mike Phillips, Mike Simmons, Roy Salisbury, Shahrin Ahmad

Views tonight: Horsehead Nebula, Flame Nebula, Europa Transit of Jupiter with Great Red Spot, a cluster of sunspots, Rosette Nebula, a near-Earth asteroid, a capture of Barnard’s Loop, Orion Nebula, M81, various telescopes of the astronomers, our moon, another transit of Jupiter by one of the moons, M67, NGC 2169-the “37” Cluster, our moon – full view, California Nebula.

We hold the Virtual Star Party every Sunday night as a live Google+ Hangout on Air. We begin the show when it gets dark on the West Coast. If you want to get a notification, make sure you circle the Virtual Star Party on Google+. You can watch on our YouTube channel or here on Universe Today.

Giant sunspot convulses but all quiet on the aurora front … for now

What a crazy sunspot cycle. Weeks go by with only a few tiny spots freckling the sun, then all at once a monster group big enough to swallow 10 Earths rounds the eastern limb and we’re back in business. I’m happy to report we’ve got another behemoth snapping and crackling with M-class (moderately strong) flares – Active Region 1967, a hunk-a-hunk of burnin’ funk that rounded the solar limb a week ago.

NOAA weather forecasters predict an 80% chance of continued M-flares and a 50% chance over the next 3 days for considerably more powerful X-class flares. This sunspot group has a delta classification magnetic field, the Facebook equivalent of “It’s complicated”.

Sunspots are made of a dark umbra and lighter penumbra. Very tiny spots with no penumbrae are called pores. A close up of the sun's photosphere shows a finely granulated texture. Granules are cells of hot gas about the size of Texas that rise from below, cool and sink. Each lasts from 8 to 20 minutes. Credit: NASA
Sunspots are made of a dark umbra and lighter penumbra. Very tiny spots with no penumbrae are called pores. A close up of the sun’s photosphere shows a finely granulated texture. Granules are cells of hot gas about the size of Texas that rise from below, cool and sink. Each lasts from 8 to 20 minutes. Credit: NASA

Sunspots have two parts: a dark core (or cores) called an umbra surrounded by a paler skirt of magnetic energy, the penumbra. They can look impressive like this one, but it’s hard to call a sunspot a “thing”. It’s really more of a locale on the sun’s bright white photosphere where bundles of powerful magnetic energy bob up from below the surface and insulate a region of the sun’s fiery hydrogen gas from the rest of the flaming globe.

We’re talking insulate as in staying cool. While the photosphere cooks at around 11,000 degrees Fahrenheit, sunspots are some 3,000 degrees cooler. That’s why they appear dark to the eye. If you could rip them away from the sun and see them alone against the sky, they’d be too bright to look at safely.

Close up of AR 1967 photographed by the Solar Dynamics Observatory at 8:45 p.m. CST Feb. 4, 2014. Credit: NASA
Close up of AR 1967 photographed by the Solar Dynamics Observatory at 8:45 p.m. CST Feb. 4, 2014. Credit: NASA

A delta-class spot group has umbrae of both polarities, north and south, corralled within the penumbra. Like bringing opposite poles of a two magnets so close they snap together, something similar can happen inside delta-class groups. Only instead of a snap, a titanic thermonuclear explosion called a flare goes kaboom.The biggest flares release the equivalent of a billion hydrogen bombs.

The huge sunspot group 1967 straddles the center of the solar disk on Feb. 3, 2014. Details: 6-inch reflector with Baader solar filter, 1/2000 exposure, ISO 400. Credit: John Chumack
The huge sunspot group 1967 straddles the center of the solar disk on Feb. 3, 2014. The smaller group, AR 1968, lies to its north. Through a filtered telescope, AR 1967 is packed with fascinating details. Photo made with a 6-inch reflector, Baader solar filter, 1/2000 exposure, ISO 400. Credit: John Chumack

We thank our lucky stars for Earth’s iron heart, which generates our protective magnetic shield, and the 93 million miles that separate us from the sun. AR 1967 has paraded right in front of our noses as it rotated with the sun. Yesterday it squarely faced the Earth – a good thing when it comes to the particle blasts that fire up the northern lights. Let’s hope it showers us with a magnetic goodness in the coming days. I really miss seeing the aurora. You too? NOAA space weather forecasters are calling for a 25% chance of auroras in Arctic latitudes overnight Feb. 4-5. We at mid-latitudes will try to be patient.

Watch Live Webcast of the Active Sun

The team from Slooh will broadcast a live Solar special focusing on the sudden emergence of hyperactivity on the Sun — lately attributed sunspot AR 1944. Right now, the Sun is in what is supposed to be the active phase of its 11-year solar cycle, Solar Cycle 24. While this has been an unusually quiet solar maximum, lately the Sun has been more active.

The broadcast will feature live feeds of the Sun from the Prescott Observatory run by Matt Francis and Slooh astronomer Bob Berman. They will provide live expert commentary during the 30 minute broadcast. The Solar Special will start at 10:00 AM PST/ 1:00 PM EST/ 18:00 UTC on Wednesday, January 15th.

You can watch live, below, or the replay if you missed it live:

Astrophoto: A Man-Made Sunspot

The Sun has been active recently along with showing several sunspots. But astrophotogher Efrain Morales captured an additional ‘man-made’ sunspot as the International Space Station transited across the face of the solar disk.

“It was a challenge as the Sun was low on the horizon at 19.5 deg. elevation, just above the canopy of the forest,” Efrain said via email, “along with and the ISS being over 250 miles distant from my location passing over Haiti at the time. His home base is the Jaicoa Observatory in Puerto Rico.

Equipment: SolarMax40, P/B CGE mount, Flea3 Ccd.

Below, see an animation of the ISS transit:

Animation of the International Space Station Transiting across the disc of the Sun on January 9th at about 20:32 UTC. Credit: Efrain Morales.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Astrophotos: Monster Sunspot Evolution


Caption: A 5-day sequence of sunspot group AR1520. Credit: Shahrin Ahmad, Kuala Lumpur, Malaysia. Click to see a larger version.

There’s a monster sunspot making its way across the face of the Sun, and it’s captured the attention of several astrophotographers. This first image is from Shahrin Ahmad, who created a sequence of images as the sunspot moved to face towards Earth from the southeastern limb. He used a Skywatcher 120ED at F/15 (2X barlow) with a Baader Solar Filter and a IMG132E camera for his images.

AR1520 stretches more than 127,000 km (10 Earth diameters) from end to end, and the magnetic field of this enormous sunspot harbors energy for strong solar flares. NOAA forecasters estimate an 80% chance of M-flares and a 25% chance of X-flares during the next 24 hours, according to Spaceweather.com.

Here are some more looks at AR1520:


Caption: Closeup of monster sunspot AR1520. Credit: John Chumack.

One of our favorite astrophotographer, John Chumack, took this image of AR1520 in white light on July 8, 2012 using a Lunt Solar Herschel Solar Wedge filter, DMK 21AF04 Fire-wire Camera, 2x barlow, with 1/1000 second exposure. See more at his Flickr page, or his website, Galactic Images.


Caption: Sun and sunspots: Credit: Mike Black

Mike Black took this one on July 9, 2012

Gear: Canon 1D Mark IV + Canon 400mm f/2.8 + 2x Extender III. Baader solar film in front of lens. See more on Mike’s Flickr page.

Want to see a size comparison of AR1520? The mascot of the Solar Dynamics Observatory, Camilla the Rubber Chicken posted this comparison to Jupiter, the biggest planet in the solar system:


Caption: Size comparison of AR1520 to Jupiter. Credit: Camilla_SDO on Twitter.

Here’s a look at the previously active region on the Sun, which last week blasted out numerous M-class flares and at least one X.1-class flares, again a sequence of images from Shahrin Ahmad:

Caption: A 7-day sequence of sunspot AR1515. Credit: Shahrin Ahmad, Kuala Lumpur, Malaysia.

Thanks to everyone for sharing their images!

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

How Big Are Sunspots?

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The short answer? Really big. The long answer? Really, really big.

The image above shows sunspot regions in comparison with the sizes of Earth and Jupiter, demonstrating the sheer enormity of these solar features.

Sunspots are regions where the Sun’s internal magnetic fields rise up through its surface layers, preventing convection from taking place and creating cooler, optically darker areas. They often occur in pairs or clusters, with individual spots corresponding to the opposite polar ends of magnetic lines.

(Read “What Are Sunspots?”)

The image on the left was acquired by NASA’s Solar Dynamics Observatory on May 11, 2012, showing Active Region 11476. The one on the right comes courtesy of the Carnegie Institution of Washington, and shows the largest sunspot ever captured on film, AR 14886. It was nearly the diameter of Jupiter — 88,846 miles (142,984 km)!

“The largest sunspots tend to occur after solar maximum and the larger sunspots tend to last longer as well,” writes SDO project scientist Dean Pesnell on the SDO is GO blog. “As we move through solar maximum in the northern hemisphere and look to the south to pick up the slack there should be plenty of sunspots to watch rotate by SDO.”

Sunspots are associated with solar flares and CMEs, which can send solar storms our way and negatively affect satellite operation and impact communications and sensitive electronics here on Earth. As we approach the peak of the current solar maximum cycle, it’s important to keep an eye — or a Solar Dynamics Observatory! — on the increasing activity of our home star.

(Image credit: NASA/SDO and the Carnegie Institution)

Big Sunspot; Little Chinese Space Station

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Astrophotographer extraordinaire Thierry Legault has made a name for himself with his images of spacecraft transiting across the face of the Sun. He has done it again by capturing the first-ever image of the Tiangong-1 space station transiting the Sun. The monster sunspot, AR 1476 absolutely dwarfs the Chinese space station (inside the circle), but you can see incredible details of the Tiangong-1 below in a zoomed-in version. Legault had less than a second to capture the event, with the Tiangong traveling at 7.4km/s (26500 km/h or 16500 mph,) the transit duration was only 0.9 seconds! The size of the station is pretty small — as without solar panels the first module of the Tiangong measures just 10.3 x 3.3 meters.

Zoomed and cropped version of the first image of a solar transit of Tiangong-1, the first module of the Chinese space station, taken from Southern France on May 11th 2012. Credit: Thierry Legault. Used by permission. Inset: CNSA.

Legault’s equipment was a Takahashi FSQ-106 refractor, a Baader Herschel prism and Canon 5D Mark II camera. Exposure of 1/8000s at 100 ISO.

As Legault told us in an interview earlier this year, in order to capture such images he studies maps, uses CalSky software, and has a radio synchronized watch to know very accurately when the transit event will happen.

“My camera has a continuous shuttering for 4 seconds, so I begin the sequence 2 seconds before the calculated time,” he said. “I don’t look through the camera – I never see the space station when it appears, I am just looking at my watch!”

For a transit event, he gets a total of 16 images – 4 images every second, and only after he enlarges the images will he know if he succeeded or not.

“There is a kind of feeling that is short and intense — an adrenaline rush!” Legault said. “I suppose it is much like participating in a sport, but the feeling is addictive.”

Thanks to Thierry for sharing his latest success, and you can see larger versions of these images, and much more at his website.

Giant Sunspot Seen Through Dusty Skies

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The enormous sunspot region responsible for all the recent fuss and flares was easily visible from Earth yesterday… easily visible, that is, with the help of a natural filter provided by a New Mexico dust storm!

Photographer David Tremblay captured this image on March 7 through the dust-laden sky of Alto, New Mexico. Active Region 1429 can be seen on the upper right side of the Sun’s disk. Many times the size of Earth, this sunspot region has already erupted with several X-class solar flares and sent numerous CMEs our way — with potential for more to come!

“Blowing dust from the Tularosa Basin is so very dense that observing the sun was possible with the naked eye this evening,” noted David on SpaceWeather.com, where you can see more of his solar photos taken about the same time.

The image above was captured at 560mm with a Canon MKlll ESO1D.

View more of David’s photography here.

Image © David Tremblay. All rights reserved. Used with permission.

“Cool” Gas May Be At The Root Of Sunspots

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Although well over 40 years old, the Dunn Solar Telescope at Sunspot, New Mexico isn’t going to be looking at an early retirement. On the contrary, it has been outfitted with the new Facility Infrared Spectropolarimeter (FIRS) and is already making news on its solar findings. FIRS provides simultaneous spectral coverage at visible and infrared wavelengths through the use of a unique dual-armed spectrograph. By utilizing adaptive optics to overcome atmospheric “seeing” conditions, the team took on seven active regions on the Sun – one in 2001 and six during December 2010 to December 2011 – as Sunspot Cycle 23 faded away. The full sunspot sample has 56 observations of 23 different active regions… and showed that hydrogen might act as a type of energy dissipation device which helps the Sun get a magnetic grip on its spots.

“We think that molecular hydrogen plays an important role in the formation and evolution of sunspots,” said Dr. Sarah Jaeggli, a recent University of Hawaii at Manoa graduate whose doctoral research formed a key element of the new findings. She conducted the research with Drs. Haosheng Lin, also from the University of Hawaii at Manoa, and Han Uitenbroek of the National Solar Observatory in Sunspot, NM. Jaeggli now is a postdoctoral researcher in the solar group at Montana State University. Their work is published in the February 1, 2012, issue of The Astrophysical Journal.

You don’t have to be a solar physicist to know about the Sun’s 11 year cycle, or to understand how sunspots are cooler areas of intense magnetism. Believe it or not, even the professionals aren’t quite sure of how all the mechanisms work… especially those which cause sunspot forming areas that retard normal convective motions. Of the things we’ve learned, the spot’s inner temperature has a correlation with its magnetic field strength – with a sharp rise as the temperature cools. “This result is puzzling,” Jaeggli and her colleagues wrote. It implies some undiscovered mechanism inside the spot.

NOAA 11131 sunspot region (Dec. 6, 2010) was the most intense spot measured in this study, but far from the largest the Sun can produce. The two bottom images show the strength of the magnetic field (C) and the contrast between the interior of the spot and the surrounding photosphere (D). The first graph (A) shows how OH starts to appear in the penumbra and continues to rise as the magnetic field strength rises. Because OH forms at a lower temperature than H2, its presence implies the quantity of hydrogen molecules that could be present (B). (adapted from Jaeggli et al, 2012)

One theory is that hydrogen atoms combining into hydrogen molecules may be responsible. As for our Sun, the majority of hydrogen is ionized atoms because the average surface temperature is assessed at 5780K (9944 deg. F). However, since Sol is considered a “cool star”, researchers have found indications of heavy-element molecules in the solar spectrum – including surprising water vapor. These type of findings might prove the umbral regions could allow hydrogen molecules to combine in the surface layers – a prediction of 5% made by the late Professor Per E. Maltby and colleagues at the University of Oslo. This type of shift could cause drastic dynamic changes where gas pressure is concerned.

“The formation of a large fraction of molecules may have important effects on the thermodynamic properties of the solar atmosphere and the physics of sunspots,” Jaeggli wrote.

With direct measurements being beyond our current capabilities, the team then measured a proxy – the hydroxyl radical made of one atom each of hydrogen and oxygen (OH). According to the National Solar Observatory, “OH dissociates (breaks into atoms) at a slightly lower temperature than H2, meaning H2 can also form in regions where OH is present. By coincidence, one of its infrared spectral lines is 1565.2nm, almost the same as the 1565nm line of iron, used for measuring magnetism in a spot and one of the lines FIRS is designed to observe.”

Spectral lines are the unique "fingerprints in light" that all atoms and molecules produce. In the presence of a magnetic field in a hot gas, some lines split, betraying the presence and strength of the magnetic fields. Each line corresponds to electrons giving up energy in discrete amounts, or quanta, as light. Imposing a magnetic field on the atom makes the electrons produce multiple lines instead of one. The spread of these lines is a direct measure of the strength of the magnetic field, and is greater in the red and in the infrared spectrum. This image depicts sunspot spectra taken by FIRS with lines centered at 630.2nm (left) and 1564.8nm (right). Note the broadened area in the color ellipses, indicating line splitting inside a spot, and how the broadening is greater at the longer wavelength. Contrast is adjusted to enhance visibility in the inset boxes.

By combining both old and new data, the team measured magnetic fields across sunspots, and the OH intensity inside spots, judging the H2 concentrations. “We found evidence that significant quantities of hydrogen molecules form in sunspots that are able to maintain magnetic fields stronger than 2,500 Gauss,” Jaeggli commented. She also said its presence leads to a temporary “runaway” intensification of the magnetic field.

As for the anatomy of a sunspot, magnetic flux boils up from the Sun’s interior and slows surface convection – which in turns stops cooler gas which has radiated its heat into space. From there, molecular hydrogen is created, reducing the volume. Because it is more transparent than its atomic counterpart, its energy is also radiated into space allowing the gas to cool even more. At this point the hot gas primed by the flux compresses the cooler region and intensifies the magnetic field. “Eventually it levels out, partly from energy radiating in from the surrounding gas. Otherwise, the spot would grow without bounds. As the magnetic field weakens, the H2 and OH molecules heat up and dissociate back to atoms, compressing the remaining cool regions and keeping the spot from collapsing.”

For now, the team admits that additional computer modeling is required to validate their observations and that most of the active regions so far have been mild ones. They’re hoping that Sunspot Cycle 24 will give them more fuel to be “cool”…

Original Story Source: National Solar Observatory News Release.