Monday, May 5, 2014

Farewell Mars, welcome Saturn

still a bit of detail visible on mars, but it's fading rapidly
learned this apparition how important the weather/time of day on mars is for imaging
in addition to whether/seeing here:

here's mars at opposition very bright, poor seeing:

guessing it's late summer on mars as the polar cap (upper right) is extremely small
there's not much more detail to see
as this portion of the surface is uniform
through a small scope with mediocre seeing you'll have trouble seeing much more than an orange/tan disc.

here's mars at closest approach:


a bit more contrast, but still not much detail, making this a tough one visually as well.
btw the white dot in the center is a cloud hovering on the left side of olympus mons,
largest mountain in the solar system

and finally, a night of decent seeing
with the low albedo (dark) regions prominently on display:


the surface structure was obvious in the scope on this evening
the mid to upper right dark patch is syrtis major i think.
the dark patches are areas where wind has blown away the tan iron oxide dust
showing darker rocks

after finishing mars on the evening above
i turned the scope on a bright object rising in the east:






low magnification as it was only 30 degrees above the horizon

8"SCT FL ~2000 mm, ASI 120 MC Camera 5ms video exposures
some images barlowed 2.5x or upsampled 2x

Sunday, April 20, 2014

blood moon

caught the eclipse last week
though looks a bit more easter egg than blood to me
with all the blood moon headlines, today's media is too obsessed with game of thrones me thinks
though biblical obsession with lunar eclipses around easter/passover abound
we won't mention the 2004 world series :(

i have to say a lunar eclipse is an event which is so difficult in dynamic range, scale, and time, that it can't be captured well in a photograph.
you start with a full moon which is slightly dimmed in the penumbral phase.  then over the course of an hour, a shadow crosses the moon--as if it's going through it's phases in an hour instead of a month, except the shadow is coming from the wrong side.  The tiniest sliver of white is still bright enough to blot out most of the stars and any color which might be seen in the dimmed section of the moon.  10 minutes later the moon appears full again, but much more dark with an eery orange color.
experiencing the event, it's easy to view orange detail in the lunar disk, and the broad background with colored stars in an instant, but photographically it's difficult to represent this due to limitations of image scale.

here's my attempt:
first an animation of the event combining images taken at 10 minute intervals:

a close up of the moon during full eclipse:

a wider field during full eclipse
the blue dot lower right is spica, a bright star in virgo
a close up of the orange dot upper right shows...
mars of course
best mars shot of the season upstaged by the eclipse 

photo details
animation
nikon D 60 
AF-S DX NIKKOR 55-300mm f/4.5-5.6G ED VR
fl 300mm
iso 100
1/400 sec exposures except 1/100 last crescent
eclipse phase too dark even at 1 sec on shaky tripod

wide field
nikon D 60
AF-S DX NIKKOR 18-55mm f/3.5-5.6G VR
fl 50mm
iso 100
5 sec exposure

close up
Takahshi FS 60 C @ ~450 mm
DMK 41 astronomy camera

mars
Celeston Nexstar 8 GPS @ ~2000 mm
zwo ASI120MC camera
5 ms exposures ~133fps
stacked best 5% of ~35,000 frames

the final eclipse image in the animation was too dark
so a composite image was used bringing in brighter detailed luminance from the close up
and color from the wide field.  




Tuesday, April 8, 2014

Mars Opposition, Ganymede

i know i've sent lots of Jupiter this season

but it's still up there and i caught something surprising the other night:
you can clearly see Jupiter, moon Io lower left and Io's shadow at the lower left edge of Jupiter.



look closely below the shadow lo
lower left and you can see Ganymede transiting the face of Jupiter
now look closer still at Ganymede and you'll see the bottom half is white and the top half brown...
meaning surface detail on one of Jupiter's moons has been resolved
which is a new milestone for me
(8"SCT FL ~2000 mm, ASI 120 MC Camera, stack of ~500 of 10,000 5ms video exposures)

Mars is at opposition right now!
prime viewing will last for another week or so, then it won't be back for 20 months, so go out and see it now
here's a shot from last night during poor seeing:

same specs as Jupiter

Monday, February 17, 2014

Jupiter's getting better

actually, i think best ever for me
it's all about seeing which was above average for a few days
allowing me to take advantage of a new planetary camera
(more details at picasa album)
2/12/14:

2/16/14 Europa and shadow with great red spot rotating out of view:


Saturday, February 15, 2014

Jupiter Overview

Jupiter is up for prime viewing this month so here's an overview of the king of planets.
5th planet from the sun, largest, a gas giant covered with clouds. 
The white clouds seen on the surface are thought to be ammonia crystals. Darker shades may be due to phosphorus, sulfur, or hydrocarbons stirred up from lower levels. 
The great red spot is a persistent storm that's been visible for as long as we've been able to see it with telescopes. 

Known as the amateur's planet because there's always something going on:
-the 4 bright Galilean moons rotate around the planet, sometimes casting shadows as they cross over the face, other times disappearing from view as they move behind Jupiter or its shadow, only to reappear hours later. 
-the great red spot can be seen at times.  the spot rotates with the clouds on the planet's surface coming into view every 10 hours
-a number of significant planetary events have been discovered by amateurs including major meteor strikes leaving transient spots on the surface, formation and disappearance of normally consistent bands, spots, etc. 

Low power view with binoculars will show a disk with the 4 Galilean moons in various arrangements in a line around the planet.  modest magnification with a telescope (60-80x) will reveal several cloud belts on the surface:

the face of jupiter typically has two prominent dark stripes across the center along with grey/brown regions at the poles.



at higher magnification (100-200x) with good seeing and the right time you may see the Great Red Spot as well as smaller white ovals:












here's Europa and shadow crossing the face:















double, then rare triple shadow transit

















One year, one of Jupiter's dark belts disappeared, returning several months later:






at one point, a second red spot appeared
here's red spot junior, barely visible at the tip of the arrow:







the slightly blue patches in the central white band are areas of clear sky, blue for the same reason ours is (i think):






a neat trick is to take two photographs of Jupiter 20 minutes apart.  the rotation allows you to create a 3D pair:

Friday, February 14, 2014

something red for valentine's

fair seeing last night
in time for a valentine's
shot of the GRS












20 minutes rotation:

stereo pair











put a paper between the two and view binocular style for a 3-D effect

Sunday, February 9, 2014

Jupiter Callisto transit

seeing has improved from poor to mediocre
here's a bit better shot of Jupiter with moon Callisto and shadow transiting the face: