In the Sky this Week – September 12, 2017
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Mercury is about as high as it’s going to get in the eastern predawn sky on the 12th, and will start getting lower each morning. Sirius is high in the sky, and the constellation Canis Major is now fully visible above the southeastern horizon before sunrise. Mercury and Mars will appear very close to each other in the eastern predawn sky on the 16th. Saturn continues to be a great observing target in the southern sky after sunset. The Moon will be in conjunction with the star Aldebaran on the morning of the 12th, and will appear between(ish) the stars Aldebaran and Betelgeuse on the 13th. The eastern predawn sky on the 18th should look pretty interesting: Mercury, Mars, a sliver of a waning crescent Moon, the star Regulus and Venus will all appear in a line. Sunspot AR2680 has rotated into view; this sunspot is about the same size as AR2673 was from last week – which ballooned out and blew off … Continue reading

Sun Spots, CMEs, and Solar Storms!
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Oh my! Sol apparently didn’t get the memo that it’s past solar maximum, and time to be heading towards solar minimum. There are a couple massive sunspot groups (Active Regions) on the Sun, and one in particular has magnetic fields harboring enough energy to generate X-class solar flares. AR2674 hasn’t changed much in size over the the last few days, but it is still a very active region with large coronal loops. AR2673 was an innocuous little spot last week, then over the weekend ballooned out into an area larger than the Earth, with intense magnetic fields. On September 4th, AR2673 spit out a Coronal Mass Ejection (CME) towards Earth – due to hit Earth’s magnetic field today (Sept. 6th), and causing G3-class geomagnetic storms on September 6th and 7th; effects can include: GPS problems, intermittent HF radio, spacecraft surface charging, power system voltage corrections, etc… Aurora watchers may want to keep an eye on the Auroral Oval, as increased auroral activity … Continue reading

NASA Has Reestablished Contact with the STEREO-B Spacecraft
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On August 21, 2016, communications was reestablished with STEREO-B spacecraft – one of NASA’s Solar Terrestrial Relations Observatories. Communications with the spacecraft were lost on October. 1, 2014; using NASA’s Deep Space Network, the STEREO team attempted monthly recovery operations to try to regain contact with the spacecraft, and their efforts have paid off! The Deep Space Network (DSN) locked onto the STEREO-B downlink carrier at 6:27 p.m. EDT. The signal was monitored by the Mission Operations team for several hours, then the spacecraft’s transmitter was switched off to conserve battery power. The STEREO team will perform further recovery operations to assess the health of the observatory’s subsystems and instruments, and to re-establish attitude control. Communications with the STEREO-B spacecraft were lost during a test of the spacecraft’s command loss timer – a hard reset that is triggered 72 hours after the spacecraft has gone without communications from Earth. This function was being tested by the STEREO team in preparation … Continue reading

“There’s a little black spot on the sun today”
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Sunspot AR2529 (“AR” = Active Region) is anything but little – you could fit the entire Earth inside it! It’s so large, it can be seen using solar filter glasses – without any magnification! It’s surprising to see such a large sunspot at this time, as the solar cycle has past solar maximum, and the Sun’s activity has been steadily decreasing; sunspots have been infrequent in recent months. Amateur astronomers have been targeting the sunspot, and producing some spectacular images: SpaceWeather.com says: “a minor CME from sunspot AR2529 could deliver a glancing blow to Earth’s magnetic field. Such an impact would add to the effect of the solar wind stream, already here. NOAA forecasters estimate a 70% chance of more G1-class geomagnetic storms on April 13th.” See more images of the Sun NOW: http://sdo.gsfc.nasa.gov/data/ Read More: http://www.universetoday.com/128325/huge-sunspot-turns-earthward/ … Continue reading

Heliopause in your sink
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A couple of years ago (in 2013) NASA announced that Voyager 1 had “left the solar system”, by which they meant that it had crossed the Heliopause. (For more on this topic, see this recent post by Bob Trembley.) A recent question I received asked when the New Horizons mission to Pluto would be likely to reach the Heliopause itself. The answer to that one is, of course, “it depends…” But an article in the Smithsonian notes that it is following in roughly the same longitude of space as Voyager 2, which passed the orbit of Pluto (but not Pluto itself) in 1989, and it hasn’t reached the heliopause yet. New Horizons has power to keep it transmitting well into the 2030s, but it may well take that long to reach this boundary. The bigger question, of course, is… what is the Heliopause? My PhD thesis advisor at the University of Arizona, Randy Jokipii, had a wonderful way to illustrate what that boundary … Continue reading

A Half Hour of the Sun
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For years now, NASA’s Solar Dynamics Observatory (SDO) media creators have produced spectacular videos of events happening on and around our local star. This time, they have outdone themselves. Presented for your approval: Thermonuclear Art. A half-hour of the Sun, in ultra high resolution – sit back and enjoy! This video is public domain and can be downloaded at: http://svs.gsfc.nasa.gov/12034 The SDO is an orbiting space telescope that has been observing the Sun in multiple frequencies since 2010. It has a continuous science data downlink rate of 130 Megabits per second (Mbps). ALL that data is publicly available; you can generate time-lapse videos of the Sun, and download them from their website.   … Continue reading

New Dual Dynamo Solar Model Predicts Maunder Minimum for Cycle 26
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A new model of the Sun’s solar cycle is producing unprecedentedly accurate predictions of irregularities within the Sun’s 11-year heartbeat. The model draws on dynamo effects in two layers of the Sun, one close to the surface and one deep within its convection zone. Predictions from the model suggest that solar activity will fall by 60 per cent during the 2030s to conditions last seen during the ‘mini ice age’ that began in 1645.  Results will be presented today by Prof Valentina Zharkova at the National Astronomy Meeting in Llandudno. It is 172 years since a scientist first spotted that the Sun’s activity varies over a cycle lasting around 10 to 12 years. But every cycle is a little different and none of the models of causes to date have fully explained fluctuations.  Many solar physicists have put the cause of the solar cycle down to a dynamo caused by convecting fluid deep within the Sun.  Now, Zharkova and her … Continue reading

Active Sunspot Groups Rotating Into View
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A rather large set of sunspots is coming into view on the Sun. This mosaic of images shows the spots on the photosphere (upper left) and the same region in different frequencies – there’s a LOT of activity right now. Spaceweather.com says that “NOAA forecasters estimate a 55% chance of M-class flares and a 20% chance of X-flares on April 14th.” You can see the Sun NOW on our site here. … Continue reading

Encore: SDO Shows the Sun in a New Light
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Encore: on Wednesdays, we repost the best posts from previous months, and make them publicly available. To comment, please see the original post. I have a lecture about the Sun – during my presentation, I show this video from the NASA’s Solar Dynamics Observatory – the audience never fails to =gasp!= or =wooh!= when they see this! I showed this to a classroom full of 90 3rd grade students, and their eyes nearly popped out of their heads! I show a couple other video too, like this one showing beautiful Coronal Loops: and this one, showing a very active region of the Sun: The SDO website has “The Sun Now” – a section that shows the Sun in near real-time, in several different frequencies. The images below are live from the SDO site: You can also create your own movies of the Sun from the SDO site! Go HERE, pick your desired date range, select a frequency, select a resolution, … Continue reading

SDO Shows the Sun in a New Light
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I have a lecture about the Sun – during my presentation, I show this video from the NASA’s Solar Dynamics Observatory – the audience never fails to =gasp!= or =wooh!= when they see this! I showed this to a classroom full of 90 3rd grade students, and their eyes nearly popped out of their heads! I show a couple other video too, like this one showing beautiful Coronal Loops: and this one, showing a very active region of the Sun: The SDO website has “The Sun Now” – a section that shows the Sun in near real-time, in several different frequencies. The images below are live from the SDO site: You can also create your own movies of the Sun from the SDO site! Go HERE, pick your desired date range, select a frequency, select a resolution, select movie download, and submit. The movies below were created from data between Jan 18-23, 2015:     Got Fluff? My wife brought … Continue reading