10/23/14 partial eclipse animation

finally finished the animation of the partial eclipse in hydrogen alpha.

imaged over about two hours.

a "usb fault" caused me to miss the very beginning while trees interfered with the end.

here's the full disk animation (large file) over 2 hours:

full disk eclipse animation

though the sun spots were dramatic in white light, they were less prominent in hydrogen alpha at this scale.

other than the moon passing by, there was not a whole lot happening during the time period of the animation at large scale.

Here's the sunspot, AR 2192 in hydrogen alpha:

Here are 150% enlargements of two small sections that showed some activity:

solar active region AR 12192: the monster revisited

here's a wider view of the monster sunspot grouping i caught just before the recent partial eclipse.
according to one source, this grouping, known as AR 12192 is one of the largest sunspot groupings in recorded history

fortunately, it arrived at a time when i was working on my sunspot technique and had made great strides, imaging structures i'd never been able to catch before.  specifically, the honeycomb-like granular structure on the bright surface and the and the "penumbral filaments" at the edge of the dark spot (best seen around the large spot to the right). 

"Granules on the photosphere of the Sun are caused by convection currents (thermal columns, Bénard cells) of plasma within the Sun's convective zone. The rising part of the granules is located in the center where the plasma is hotter. The outer edge of the granules is darker due to the cooler descending plasma." (Wikipedia)
These convection currents contribute to the sun's magnetic field.

the penumbral filaments at the edge of the dark spot aren't that well understood (at least by me).  they seem to involve an interaction between magnetic fields of different orientations and convective flow.
magneto-convective cell reference

the sun rotates once every 27 days or so
will be interesting to see if this grouping comes back around.  

the key to the improved image was taking a huge number of frames over a short period and discarding all but the very best.  to do this i had to use a different camera with a smaller field of view and faster frame rate.  unfortunately, the field of view was smaller than this large grouping.

compare the detail (especially the fine filaments) on this small high frame-rate field to the right side above:

i tried a mosaic in an attempt to get a wider field and high frame rate, but it came out to too patchy

for reference here's a prior image at the same scale:

IMAGE improvement DETAILS
the following measures gave improved images:
1. switched cameras from DMK 51 to zwo ASI120MC which allows a much higher frame rate.
-DMK is great for wide full disk animations, but limited to 12 fps-i'd misread the framerate as 60 fps-that's the output avi :(
using a partial frame with the zwo got me to an average of 54 fps which overcame the handicap of the color camera
2. much smaller stack: took only the best 20 or so images at the upward curve to the left of registax stackgraph quality indicator.
3. kept the imaging time very short--20 seconds
4. put the solar filter (baader film) on the scope inside and immediately pointed it at the sun when i brought it outside.
-the charcoal black carbon fiber tube heats up very quickly with direct sunlight. rather than insulate, i figured the film would reflect the energy immediately, keeping the tube out of direct light. 

i think the biggest factor was limiting the stack size
which means i can reprocess some of my older images :)

did not recollimate
tried an off-axis mask prior to these changes with no improvement
no change in focus technique

solar selfie from 10/23/14 eclipse

why call it a silhouette when i can be trendy?
if you look around while the sun is partially eclipsed, you may notice strange things in the shadows: a blurring of the sharp line between light and dark, strange shapes in light.  leaves in the trees may create a pinhole camera effect giving projections of the eclipsed sun on the ground.
i couldn't find an example in the immediate area so i made one myself ;)

I know, you're thinking that's just my first web space casting a shadow.  Here's a more dramatic example i encountered indoors created by holes in the blinds:

eclipse preview and a monster spot

as usual, the sun has upstaged the moon, producing the largest sunspot folks have seen in years at the same time as the partial solar eclipse.  it's so big folks are simply referring to it as the monster.  larger than jupiter and easily visible without magnification (eclipse glasses only).
here's a section of it:

and here's the full disk in hydrogen alpha mid way through the partial eclipse:

more to follow...

solar surface animation, eclipse alert 10/23/14

OK first up
there will be a solar eclipse visible from the US on thursday 10/23/14.
http://shadowandsubstance.com/#Partial
needless to say, as it's only a partial eclipse, the sun will still be blindingly bright.
protective eye-wear or projection is a must for viewing.

not much happened in my full disk Ha animations.
close-ups of prominences however gave interesting movements.
so here are some close ups of the disk surface.
not quite as dramatic as a prominence lifting off, but still interesting.
first, here's the full field (click on image for full size):

high contrast grey-scale

here's a circular filament around an active region:

here are what look like classic magnetic field lines from one sun spot to another:

a filament arching off the surface:

eruptions around a sun spot, which, i guess is why they're called "active regions":

imaging details:

7/5/14 newport beach, ca

DMK 51, 2.5x Powermate, Lunt 60 PT B1200

2 hours of imaging at ~12 fps every other minute

best 300 frames every minute

7.8 ms exposure

the images were spoiled by dust on the sensor

finally salvaged them by creating artificial flats

though you can still see some faint shadows of dust spots in the animations

(right side of last)

Saturn 2014

forgot to send out this year's best shot:

getting some nice color in the bands
a hint of the north polar cloud, but no hexagon
can see Cassini's division and the maybe Encke minimum

the images are taken by using a video camera, stacking thousands of short long exposures
allowing processing software to select the images least distorted by seeing
stacking thousands of images in this way gives a much more sharp image

in theory one can upsample the video by 2x to get better magnification
so i decided to do a test, comparing and upsampled image
with an image using a 2.5x barlow to give more magnification
but requiring longer exposure.

which will be better?
larger magnification with longer exposure
or shorter exposure eliminating seeing effects?

2.5x barlow:

upsampled 2x:

compare the Encke minimum and colored bands

close, but i think the barlow wins
though the seeing wasn't really sufficient for either

saturn overview

Saturn
6th planet from the sun, second largest after jupiter
a gas giant

it has a slight yellowish color due to ammonia in the upper atmosphere
with faint bands (much less dramatic than jupiter's)
and...

IT HAS RINGS!

first view of saturn through a telescope:
unknowingly, i pointed the scope at a bright "star" rising in the east
and was shocked to see it had rings...
a shudder and a concrete sense that there really is more out there than we know.
there's something about the rings and the shadow they cast over the sphere that makes it appear much more like a perfect 3-dimensional structure than a simple disk. 

the gap in the rings is called the Cassini division.
the darker band outside the cassini division is called the Encke minimum.
there's a near mythical gap outside of that called the Encke division.
that is only visible from earth with under excellent seeing conditions with high quality optics.

the angle of the rings varies from year to year as saturn makes its 29.5 year orbit around the sun.
in 2002 they were maximally tilted with the south pole facing us
(about the time i bought my largest scope)

here's one of my earliest shots from 2004:

in 2009, they were edge-on

though many find this the worst time to view saturn
i found the iconic line made an interesting image:

the rings are now opening again

peaking in June 2017 with the best view of the rings and the north pole of the planet (this event will sell lots of telescopes ;)

there's something special about the north pole:

the dark patch at the north pole is actually hexagonal!

it is a persistent cloud pattern, similar to jupiter's great red spot
santa's helpers must be more mischievous on saturn
i've yet to see or image it, but as the north pole continues to tilt
towards us i'm hoping to catch it


saturn has 150 moons and counting
the largest, titan, is larger than mercury and contains it's own atmosphere as well as hydrocarbon lakes.
titan casting shadow on saturn's surface:

9 or 10 can be seen thru an amateur telescope

enceladus is notable for salt water geysers which contribute to saturn's rings

more on saturn:
http://solarsystem.nasa.gov/planets/profile.cfm?Object=Saturn
http://www.nakedeyeplanets.com/saturn-orbit.htm
http://www.astronomycast.com/2007/10/episode-59-saturn/
http://www.astronomycast.com/2014/05/ep-344-the-rings-of-saturn/
http://www.astronomycast.com/2007/11/episode-61-saturns-moons/
http://en.wikipedia.org/wiki/Saturn%27s_hexagon