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

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.  

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

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:

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:

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

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:

the king is dead, long live the king...comet lovejoy

another comet of the century turned out to be a bust
but despite comet ISON's demise during it's pass by the sun
there's another comet out

while comet lovejoy is by no means comet of the century
it's one of the best comets i've been able to photograph from light polluted skies:

this one is fairly bright, but low in the sky
rises above my treeline at 15 degrees in the east at 5 AM, too bright to photograph by 6
so only had a narrow window to image it.
this is a stack of 20x2 minute exposures tracking on the head of the comet
which is moving relative to the stars, explaining the trails

here's an animation of the 20 individual frames aligned on the stars
showing the comet's motion (big file):

comet lovejoy motion

should remain fairly bright thru the month of january, rising higher in the sky
shame it's been overshadowed by ISON. 

bill w

new year's sun spots, *solar winter storm warning tonight*

last year was the year of the solar maximum
peak in the 11 year cycle of sunspot activity
this is related to the sun's magnetic field flipping
water world with fire
which means this year is...
the year after the solar maximum
and still pretty good for solar activity so far.

took some relatively high power images of sun spots on new year's day:

there was some interesting activity just visible on the other edge:

the sun's surface rotates with a period of approximately 28 days when viewed from earth...
so here it is a few days later on 1/5/14 facing us:
this was a big one which could be easily seen without magnification (looking thru filter)

on 1/7/14 a coronal mass ejection was launched from this spot aimed right at us
as a result, tonight we're going to get hit by plasma consisting of charged protons, electrons, alpha particles and such...
which means major aurora activity tonight at the poles
there's a slight chance that you may see some activity if you live moderately far north
so take a look outside
you may see some strange lights

for more on this check out
http://www.spaceweather.com/

first light from new home: Christmas Jupiter

haven't imaged in about 6 months due to move/move/remodel... Jupiter is just past opposition now and should be in excellent position for viewing for the rest of January. Here's my first light image with a new camera from new location, Jupiter on Xmas night:

unfortunately, the seeing was terrible, amazed i was able to pull anything out at all. this is an animation of two shots taken about 30 minutes apart. shows the great red spot (lower left) just rotating into view.
here it is the next night (again terrible seeing)

you can see the great red spot lower left, Io's shadow upper mid, and a hint of Io just above and to the right of it's shadow.

cheers

Crab Nebula Expansion

Here are 4 images over 6 years showing the expansion of the crab nebula, a supernova remnant. 

Extrapolating the expansion back to time 0 gets close to the observed 1054 AD supernova.  Note the bluish pulsar wind lower left, seems to be moving faster than the red filaments

4th of july supernova revisited-crab pulsar wind

On July 4th 1054 AD, astrologers observed a bright blue square in the sky near the sun at dawn. it was visible during the day for 3 weeks and at night for 2 years. 700 years later, the Crab Nebula became the first object in Charles Messier's famous catalog:

 What makes the crab nebula glow? The bluer of the two central stars is a dense neutron star,
the remnant of the original star that went supernova on the 4th, spinning at 30 revolutions per second. A strong magnetic field associated with the spinning star accelerates electrons in the surrounding space to relativistic speeds. Collisions between the electrons and surrounding matter give off very high energy photons. Rather than the central star, it is the photons from these collisions (EDIT: my physics buddies have informed me that it is the acceleration itself that causes the high energy photon emissions, no collisions needed)  that cause the gas in the surrounding filaments to glow like fluorescent lights.
pulsar wind:

enamored with the concept of the pulsar wind, i attempted to capture it with a filter which blocks the emission line signal, giving only the broad band pulsar wind. a quick look at the crab nebula spectrum shows a wide region devoid of emission lines

after making a few calls, trying to get a nice wide filter in this region, i found a custom filter would cost more than my camera. so i went with a narrow filter in the region that was available in order to capture this broad band signal. i had hoped to capture some motion with the filter, but the broad band emissions were so weak with the narrow filter, that i was unable to get enough detail on any given night (or two) to convincingly demonstrate motion.

in any event, the combined stack gives a nice view of the pulsar wind without the pesky emission lines obscuring the view. i find the blink fascinating, tracing the swirls, wisps and arcs of broad band emission, and then following them into the combined image.

here's my 2011 crab nebula animation showing some motion in the broad band.

happy 4th

-bill w

sun and moon for summer solstice

 this is the year of the solar maximum--maximum sunspot activity in the 11 year solar cycle.
10 pm pacific today 6/20/13 is the summer solstice.
what better time for solar images?

here are two images of the sun taken at about the same time with different filters. 

first up, the sun in "white light", using a filter that blocks out 99.999% of the sun's light
you can see a few dark sun spots (which are still blindingly bright without filters), a slightly granular appearance, and a few lighter areas.  this is the photosphere which is basically the surface of the sun.
the second image is the sun imaged with a hydrogen alpha filter that allows all of the sun's light at a specific frequency, which corresponds to absorption and emission of light due to hydrogen.  this shows the chromosphere, a thin layer above the photosphere dominated by hydrogen emissions.  it usually can't be seen as it is overwhelmed by bright emissions from the photosphere.  the hydrogen alpha filter allows us to see the chromosphere's wavy filaments and prominences.
you can still see hints of sunspots, but there's much more going on. 

next i colorized the image and then lightened it dramatically to show the faint prominences (things shooting off the disk around the rim).  since this overwhelmed the central detail, the original darker image was superimposed to maintain some of the surface detail.  bear in mind the prominences seen at the edge are much more faint than the central detail.  the dark line upper right across the face is called a filament.  it's basically the same phenomenon as a prominence, but coming off the surface towards the viewer rather than occurring at the edge. 

last up is the full moon, which happens to be the same size as the sun, which is convenient for things like eclipses
and finding something to do with your solar rig at night. 
this was taken with the same scope and camera as the first image, leaving off the filter. 
why do astrophotographers rarely image the full moon? 
the sunlight is shining straight down on the face which washes out the detail of landscape. 

the sharp eyed viewer will note better contrast at the extreme bottom portion of the image
where a few shadows are cast enhancing detail in this moon that was 6 hours away from full. 

have a good summer

whw

Mother of a Prom

interrupting the planetary overview.

lot's of solar activity on mother's day

here's a close up with the bright disk blocked out to emphasize the faint prominence:

still working on full disk versions

Mars

will skip earth and the moon for now
and move on to the 4th planet from the sun
Mars aka the red planet

mars is a small planet, about half the size of the earth
with mass equivalent to mercury

Mars is the only planet who's surface detail can be seen from the earth
(detail seen on other planets is related to clouds)

The red-orange appearance of the Martian surface is caused by iron oxide (basically rust) in the soil
as well as a reddening effect due to dust in the atmosphere.
many areas have blue tinted rocks altering the surface color.

the squiggly line upper right of center is a giant dust storm on the surface.
the white dot upper left is a melting polar cap
made of carbon dioxide and some water ice.

the polar caps change with the martian season
and can be followed in the telescope when mars is in view:

the orbit of mars is relatively close to the earth's
as a result detail in mars is only visible through telescopes
as the earth approaches mars in it's orbit
this occurs every 20 months (approximately)
and lasts for 4 to 6 weeks, with the best viewing for only 2 weeks
so folks get excited when this occurs
the next will be in april 2014 :(

this of course is the time when mars goes into retrograde motion
as the earth passes mars
(which we all learned about in earth science and promptly forgot)
http://en.wikipedia.org/wiki/Mars#Astronomy_on_Mars

more stuff

mars has two moons
Phobos and Deimos
Phobos is in a decaying orbit, slowly falling to the surface
which brings up an interesting tangent

classic example of the Roche limit:
as Phobos descends to the surface of mars, the gravitational force acting on it will increase.
gravitational strength varies with distance.
so at some point during the descent the gravitational pull on the near side of the moon will by *much* greater than the pull on the far side.
stronger than the force holding the moon together.
the net result is that the moon will break apart, potentially leaving a ring on the way down.
this point is known as the Roche limit

an extreme example of this occurs near black holes where matter is torn apart in strings pointing towards the black hole
a process known as spaghettification
which is fun to say
https://en.wikipedia.org/wiki/Spaghettification

lastly, the sci-fi book red mars

http://www.amazon.com/Red-Mars-Trilogy-Stanley-Robinson/dp/0553560735
considered "hard" sci-fi
gives what seems like a very real depiction of how mars could be colonized
has a feel similar to 50's sci fi accurately predicting space flight and moon walks
with lots of detail on martian planetology, whether, etc
warning:
very dark book, heavy on planetology, weak on biology

whw

Venus

Venus, about the same size as earth

the second planet from the sun

rocky, but covered with white clouds
which make it one the brightest planets
appearing brighter than any star

like mercury, it's close to the sun
and never strays far from it
it can only be seen in the evening just after sunset
or in the morning before sunrise
but get's much higher in the sky than mercury
as a result it's know as the dawn star
and the dusk star
depending on where it is in it's orbit
some have suggested that it took the ancients quite some time
to figure out that the dawn and dusk star were the same thing

gallileo was the first to view venus through a telescope
and note it has phases like the moon (see below)
the phases convinced him that the sun was the center of the solar system
not the earth
which was correct
but got him in trouble with the church

the cloud layer on venus
is rich in carbon dioxide causing a greenhouse effect
making venus the hottest planet in the solar system
far hotter than mercury although further away from the sun

the similarity in size and carbon dioxide content between earth and venus
lead many to conclude that earth will eventually become like venus
with no water due to the run away greenhouse effect

here are a few images at the "half moon" phase
viewers looking through a telescope for the first time
mistake it for the moon

and here's a shot of venus as it crosses in front of the sun

Mercury

continuing with the planet tour

mercury
closest planet to the sun
fastest in orbit circling the sun in 88 days
named after the fleet footed messenger god mercury
small, rocky, hot, no atmosphere
surface covered with craters
even though extremely hot, some craters near the poles cast shadows creating areas never touched by sunlight.  there appears to be water--ice in these areas

since it's so close to the sun it can only be seen just before sunrise or just after sunset
as a reddish dot near the horizon seen through turbulent atmosphere:

it has phases like the moon
a bit of imagination suggests a dark shadow upper left similar to a gibbous moon

on rare occasions mercury can pass directly in front of the sun, leaving a dark spot where the sun's rays are blocked:

note the sun spot lower left is much bigger than the planet mercury


whw

The Planets

a few past emails i've sent out seemed appropriate for the start of the blog so here we go...

someone asked for info on the planets for their child, so i thought i'd spam the list with some of my older pictures.

since pluto was demoted in 2006, there are only 8 planets in our solar system. 
in august 2003, mars was closer to the earth than usual due to the aligment of the orbits of the two planets.  it will not be this close for another 60,000 years. 


this event was widely popularized in the press (astronomers love to popularize rare events--seems like they come up with a different one every month).  the original story included the following message: "At a modest 75-power magnification Mars will look as large as the full moon to the naked eye".  interestingly, this event spurred my interest in astronomy, causing me to purchase a telescope to show my 5 year old son. 

since then, every august a bogus email comes out stating that mars will be as large as the full moon in august (omitting the telescope part). 

just for fun, one august, i stayed up all night, taking pictures of all the visible planets at the same image scale.  so here are the planets as seen from earth except saturn and mercury which were behind the sun.  i used photoshop to place them all in a row on the right.  in order of appearance during that night, from top to bottom we have Jupiter, Neptune, Uranus, Mars, and Venus.  

the Moon of course is seen on the left, too big to fit entirely in the frame--clearly *much bigger than mars*.  sharp-eyed viewers may note two small specks to the left of jupiter--two of it's moons--pay no attention to photoshop artifacts. 

about the photo: this one made it to the finals of an amateur photo contest, spawning many copy cat compositions.  the president of my astronomy club implied i was too sarcastic in a reply to someone making the giant mars claim which included this photo...MOI?

whw
astro.whwiii.net
ocastronomers.org