Forecast: Explosive sunspots with a chance for auroras tonight, this weekend

Venus shines above a beach in Maui, Hawaii late last week. Island of Lanai in the distance. Waves are lit by firelight. Credit: Bob King

Just returned from a wonderful trip to the island of Maui in Hawaii where Venus shines high in the western sky after sunset and a handful of professional observatories track the comings and goings of wayward satellites, comets and asteroids from a dormant volcano 10,000 feet above the Pacific Ocean.  I’ll have more Maui astronomy to share with you soon, but for the moment, let’s focus on the sun.


Views of the sun in a variety of wavelengths of light showing the flares from sunspot groups 1875 (top right bright patch) and 1877. Solar Dynamics Observatory 

More than one sunspot group has been blasting stuff in Earth’s direction this week. The two largest sunspot groups – active region 1875 and neighboring 1877 – both have complex magnetic fields that have spawned hefty flares. 1875 kicked out a medium M4 flare on Oct. 22 while region 1877 upped the ante with a powerful M9 class flare Wednesday evening CDT.

The sun late this afternoon CDT Oct. 24 taken by the Solar Dynamics Observatory. Both regions 1875 and 1877 are big enough to see with the naked eye with a safe solar filter. Credit: NASA

The M9.3 is just below the X-class flare level, the most energetic category.  The material the explosion shot into space appears to be directed toward Earth with a possible arrival this weekend. Should northern lights materialize, a late-rising third quarter moon won’t spoil the show.

With this recent resurgence in solar activity after a summertime lull, things look promising. Space weather forecasters are calling for a 15 percent chance aurora overnight tonight for mid-northern latitudes overnight from earlier coronal mass ejections. Keep a watch – I’ll be out there too.

3 thoughts on “Forecast: Explosive sunspots with a chance for auroras tonight, this weekend

  1. The odds of auroras got a little boost with an X class flare.
    http://www.nasa.gov/content/goddard/sun-emits-2nd-solar-flare-in-2-days/index.html#.UmqpOBCFcnI
    not that it matters much here as the Okanagan valley is socked with low clouds (despite a high pressure system). It’ll probably clear up by the time of the next “First Quarter”, sigh.,..
    why do I have a craving for pineapple and other exotic agricultural products ?
    Nice to have you back, Bob :)

    • Thanks BC for the link! The sun is popping hot this week. In Maui, good old solar IR and UV felt so intense on this northern boy’s back it was sunblock #50 every day. Wonderful trip – my wife and I saved a long time and went off-season to afford it. Dark skies, great hiking, snorkeling and I even made it to the Haleakala summit to see (from a short distance) the observatory complex.

  2. definitely both sunspots were visible with filtration but no magnification! was able to show a coworker. Saturday AM could only view 1 in a similar manner as their visible area is now being compressed. it was also very early which may have made some difference.

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