Reports - 2014
Astronomy Benalla General Meeting Presentation - Wednesday 17th November 2014
Solar activity October 18th to November 4th 2014 Presenter: Rupe Cheetham
The numbers below in bold type refer to slides in a Power Point presentation.
On Tuesday October 21st I picked up the Astronomy Benalla’s Solar Max60 H-alpha telescope to take to the Border
Stargaze star party and have been using it about 3 to 4 times per day since. I was fortunate to have watched and
monitored the largest Sunspot for 25 years to cross the face of the Sun as it rotates at its equator in 25.4 Earth days.
No1 Solar Activity October 18th to November 4th 2014
No2 Sunspot emerges over the western limb. There were 5 other solar scopes (4 H-alpha plus 1 white-light scope)
provided by other participants. We had plenty of participants/viewers each day checking and rechecking the rapid
changes of the Sun’s activities. I spent considerable time tuning the etalon filter on the scope to ensure each viewer
would get the best view of the type of activity they wanted to see. Since coming home I have continued to monitor the
Sun’s ongoing activities.
No 3 Oct 26th Photo taken by a Canadian pilot at 11,000 m. Notice the green fleck on the upper edge of the Sun
caused by the refraction thru the atmosphere. Besides the largest sunspot, known as AR2192 (10x Earths diameter)
we monitored 2 very large twisted filaments associated and moving with it. There was also a much brighter faculae
than normal.
No 4
What are filaments, faculae, and plages? When we see the Sun’s edges or limbs against the dark sky, we see
what appears to be bright flames or flares pointing out from the Sun - these are known as prominences. Filaments are
prominences that are on the Sun’s front surface that are pointing directly or nearly directly towards us and show up as
dark lines against the general orange/red Sun’s photosphere (”surface”) whose temp is about 5800k – this is what we
see thru the H-alpha filter. Faculae are the hotter areas, lighter colour (about 300K more) around the cooler sunspots.
Plages are the hotter patches in the Sun’s upper atmosphere, known as chromosphere and are the equivalent to
faculae. Sunspots are about 1600k cooler than the photosphere
No 5
Let’s look at a close up of a prominence taken from NASA’s Solar Dynamic Observatory (SDO)
spacecraft . A solar flare is an explosion on the Sun that happens when energy stored in twisted magnetic fields
(usually above sunspots) is suddenly released. Flares produce a burst of radiation across the electromagnetic
spectrum, from radio waves to x-rays and gamma-rays. Note the size of the Earth at the same scale.
No 6
Scientists classify solar flares according to their x-ray brightness in the wavelength range 1 to 8
Angstroms, as C, M or X.
[X class flares are big; they are major events that can trigger planet-wide radio blackouts and long-lasting radiation
storms. M class flares are medium-sized; they can cause brief radio blackouts that affect Earth's polar regions. Minor
radiation storms sometimes follow an M class flare. Compared to X and M class events, C class flares are small with
few noticeable consequences here on Earth.]
Note the six high, X class flares. Three of these explosions produced strong HF radio blackouts over the dayside of
Earth i.e. Australia and Asia. In each case, communications were disturbed over a wide area for approximately one
hour. Such blackouts can be recorded by amateur radio operators and aircraft. Usually, strong flares are accompanied
by massive Coronal Mass Ejections (CMEs), billion-ton clouds of electrically charged gas that billow away from the
blast site. None of the eruptions from AR2192 produced a major CME. Without a series of CMEs to rattle our planet's
magnetic field, there were no geomagnetic storms nor any widespread auroras. Earth-effects were limited to minor
radio blackouts.
No7 ++ Now let’s look at the movement of the super large sunspot AR2192
No 8
Taken by the SDO with a different filter enabling us to see different sections of the Sun’s layers.
No 9
and No 10 Following the movement of sunspot AR2192 through to 30th October.
No11 At the same time on the other side of the Earth, in Canada, there was a partial solar eclipse.
No 12
Peak day at the Border Stargaze. We also had two huge filaments and large prominences.
No 13 + 14+15+16+ 17
Acknowledgements: Photos from NASA.
By November 4th the Sun on Earth’s side had quietened down with just 2 average sunspots, no filaments and only
very small prominences but by Thursday 6th two large filaments had appeared and a new very active sunspot had
appeared on the western limb; but no prominences of any reasonable size.
You never know what’s coming
RGC
On Tuesday October 21st I picked up the Astronomy Benalla’s Solar Max60 H-alpha telescope to take to the Border
Stargaze star party and have been using it about 3 to 4 times per day since. I was fortunate to have watched and
monitored the largest Sunspot for 25 years to cross the face of the Sun as it rotates at its equator in 25.4 Earth days.
No1 Solar Activity October 18th to November 4th 2014
No2 Sunspot emerges over the western limb. There were 5 other solar scopes (4 H-alpha plus 1 white-light scope)
provided by other participants. We had plenty of participants/viewers each day checking and rechecking the rapid
changes of the Sun’s activities. I spent considerable time tuning the etalon filter on the scope to ensure each viewer
would get the best view of the type of activity they wanted to see. Since coming home I have continued to monitor the
Sun’s ongoing activities.
No 3 Oct 26th Photo taken by a Canadian pilot at 11,000 m. Notice the green fleck on the upper edge of the Sun
caused by the refraction thru the atmosphere. Besides the largest sunspot, known as AR2192 (10x Earths diameter)
we monitored 2 very large twisted filaments associated and moving with it. There was also a much brighter faculae
than normal.
No 4
What are filaments, faculae, and plages? When we see the Sun’s edges or limbs against the dark sky, we see
what appears to be bright flames or flares pointing out from the Sun - these are known as prominences. Filaments are
prominences that are on the Sun’s front surface that are pointing directly or nearly directly towards us and show up as
dark lines against the general orange/red Sun’s photosphere (”surface”) whose temp is about 5800k – this is what we
see thru the H-alpha filter. Faculae are the hotter areas, lighter colour (about 300K more) around the cooler sunspots.
Plages are the hotter patches in the Sun’s upper atmosphere, known as chromosphere and are the equivalent to
faculae. Sunspots are about 1600k cooler than the photosphere
No 5
Let’s look at a close up of a prominence taken from NASA’s Solar Dynamic Observatory (SDO)
spacecraft . A solar flare is an explosion on the Sun that happens when energy stored in twisted magnetic fields
(usually above sunspots) is suddenly released. Flares produce a burst of radiation across the electromagnetic
spectrum, from radio waves to x-rays and gamma-rays. Note the size of the Earth at the same scale.
No 6
Scientists classify solar flares according to their x-ray brightness in the wavelength range 1 to 8
Angstroms, as C, M or X.
[X class flares are big; they are major events that can trigger planet-wide radio blackouts and long-lasting radiation
storms. M class flares are medium-sized; they can cause brief radio blackouts that affect Earth's polar regions. Minor
radiation storms sometimes follow an M class flare. Compared to X and M class events, C class flares are small with
few noticeable consequences here on Earth.]
Note the six high, X class flares. Three of these explosions produced strong HF radio blackouts over the dayside of
Earth i.e. Australia and Asia. In each case, communications were disturbed over a wide area for approximately one
hour. Such blackouts can be recorded by amateur radio operators and aircraft. Usually, strong flares are accompanied
by massive Coronal Mass Ejections (CMEs), billion-ton clouds of electrically charged gas that billow away from the
blast site. None of the eruptions from AR2192 produced a major CME. Without a series of CMEs to rattle our planet's
magnetic field, there were no geomagnetic storms nor any widespread auroras. Earth-effects were limited to minor
radio blackouts.
No7 ++ Now let’s look at the movement of the super large sunspot AR2192
No 8
Taken by the SDO with a different filter enabling us to see different sections of the Sun’s layers.
No 9
and No 10 Following the movement of sunspot AR2192 through to 30th October.
No11 At the same time on the other side of the Earth, in Canada, there was a partial solar eclipse.
No 12
Peak day at the Border Stargaze. We also had two huge filaments and large prominences.
No 13 + 14+15+16+ 17
Acknowledgements: Photos from NASA.
By November 4th the Sun on Earth’s side had quietened down with just 2 average sunspots, no filaments and only
very small prominences but by Thursday 6th two large filaments had appeared and a new very active sunspot had
appeared on the western limb; but no prominences of any reasonable size.
You never know what’s coming
RGC
Pictures from the Hubble Site
