Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Sunday, September 21, 2014

saturn overview

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)


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:

Saturday, September 6, 2014

M 24, it's full of stars

"my God it's full of stars"
-Dave Bowman's final words prior to entering the monolith in 2001: a space odyssey.  contrary to my recollection, the line occurred only in the book version, not the movie, but was grafted into the movie as a flashback in the opening of 2010.  

Messier object 24, a/k/a the sagittarius star cloud,  isn't really a star cluster, it's just a bright patch of stars in the milky way surrounded by dust.  it can be thought of as a hole in the dust, allowing us to see much deeper towards the center of our galaxy.  (no frank, you can't see the black hole).  The bright patch can be seen with the naked eye in skies dark enough to see the milky way as a bright patch above sagittarius

the patch of red, suggested there was some glowing hydrogen in the surrounding gas, so i decided to shoot it with an Ha filter:

Here's a combined view:

interestingly i see an Ha wall along the upper right margin of the star cloud
that is more evident in the HaRGB than the Ha itself.

if it weren't full of stars it would look like this:

Lastly here's a close up of the open cluster in the upper left portion of the star cloud i shot a few years ago:

-bill w

image details:

FS 60c @ 254 mm 5.23"/px full size
field approximately 2.5x3.5 degrees
Hutech IDAS, Chroma Loglow, Astrodon 5nm Ha filters
SX H9C, ASA DDM 60 unguided
4 panel mosiac composed of approximately 17 5 minute subs RGB
15 5 minutes subs Ha
newport beach, ca

more than you wanted to know about 2001:

Thursday, September 4, 2014

Delta Aquilae is 50 light years away

Aquila, the eagle, is a summer constellation. 
It can be found here in the summer evenings section:

It’s brightest star, alpha aquilae, a/k/a altair, forms one of the corners of the summer triangle.  A huge right triangle seen overhead during summer nights. 
Delta aquilae is at the center of the eagle.  At visual magnitude 3.36 it can be seen with the naked eye in good viewing conditions.

It is 50 light years away. 

Einstein’s theory of special relativity.  Basically states that the speed of light is the same for all observers.  Consider a space ship moving away from us at half the speed of light.  We shine a bright pulse of light into space.  After a year the light has traveled one light year away from us, while the space ship has traveled half a light year.  The pulse of light is half a light year from the ship.  So if the light has only traveled half a light year from the ship, how can its speed relative to the ship be the same?  Speed=distance/time.  So the solution is that the ship has only experienced half the time we have on earth—time has slowed down. 

Consider a photon leaving delta aquilae 50 years ago.  Some of us have experienced 50 years waiting for its arrival today.  But the photon, traveling AT the speed of light experienced no time at all. 

Something to think about for this day.  

Imaging details.
FS 60c @ 254 mm 5.23"/px full size
Chroma Loglow filter
SX H9C, ASA DDM 60 unguided
13 5 minutes, 24x30s, 24x3s
"diffraction spikes" added in processing for emphasis
newport beach, ca

Wednesday, August 20, 2014

Leo Galaxy Cluster aka Abell 1367: Part 3 quasars and cosomology

Caught a number of background quasars in the field of Abell 1367.

quasars (quasi-stellar radio sources)
look like faint blue stars
but they have *very* high red-shifts
which made them somewhat of a mystery

turns out they are actually extremely distant galaxies
with black holes that are actively feeding on matter
generating massive amounts of light.
though light cannot escape the black holes,
energy is generated just outside the event horizon
by massive gravitational stresses and friction acting on the incoming material.

the most distant quasar in the image
(blue dot just below the S in QSO lower left)
has a red shift (Z) of 3.36: 

recall that the redshift of the galaxy cluster 330 million light years distant was 2.3% or .023
the QSO's red shift is 3.36 or 336%!

so how far away is it?
well here's where things get *relatively* slippery
the universe is expanding
it's taken light a really long time to reach us from this object
do we want to know how far away it is now or how far away it was when the light left the galaxy?
when it left the galaxy, our planet, solar system and sun didn't exist.
now, due to the expansion of the universe, the galaxy is moving away from us faster than the speed of light
it's current distance can never be observed

dirty cosmology trick:
nothing can move through space faster than the speed of light
but the universe itself can expand faster than the speed of light
(my head hurts)

the commonly used figure is
light travel time
which is neither where it is now, nor where it was when it emitted the light
but a measure of how long it took the photons to reach us

it gets even worse:
redshift versus distance is not linear for large distances
so in order to calculate the distance
theoretical models with various parameters including the shape of the universe!
have to be used
best estimates for the parameters change over time by one of the more commonly used estimates*, this one is
11.8 billion light years away
the big bang happened 13.7 billion years ago
the universe was a lot smaller place when light left this object

here's another small crop from the center of the image
including the Ha emitting galaxy from last time
with 3 quasars (distance in billions of light years):

interesting cosmological explanations (laymen's terms):

life the universe and everything
(be sure to mouse over the answer)

Ned Wright's FAQ on cosmology and the big bang

*Ned Wright's Cosmology Calculator

Saturday, August 16, 2014

Leo Galaxy Cluster aka Abell 1367: Part 2 Red Shift

when distances get very large, astronomers measure the "red shift" of light to determine distances:
more distant objects are moving away more rapidly due to the expansion of the universe
and therefore the light from these objects is shifted further to longer wavelengths (more red) by the Doppler effect*

this was part of Hubble's big thing,
took two very cool discoveries:
1 certain fuzzy patches had shockingly large redshifts suggesting they are "island universes" (galaxies) much further away than we had imagined.
2 a special type of variable star has a period proportional to it's absolute brightness, which means they can be used to measure distances with reasonable accuracy by comparing the measured brightness to the absolute brightness.

Hubble combined these discoveries, plotting distance to galaxies versus red shift
 and found more distant galaxies were moving away more rapidly
 proving the expansion of the universe

Abell 1367 has a redshift of 2.2%
this means that hydrogen alpha emissions at 656 nm will be shifted to 700 nm
completely out of the range of my narrow band Ha filter (5 nm centered at 656)
fortunately, i have an SII filter centered at 672 nm with a 12nm band width
allowing me to catch redshifted hydrogen emissions with a filter designed for sulfur
which is a cool trick, part of why i picked the cluster

though subtle, i caught one galaxy that definitely shows enhanced Ha emissions:

The upper right tail of this edge-on spiral galaxy (UGC 6697) is clearly blue (due to active young star formation) in standard images
but has a red patch in the middle of the blue with the SII (Ha) enhanced images
and possibly a more subtle red area around the bright core
due to hydrogen emissions in a large nebula (often found in star forming regions)
or active galactic nucleus = black hole feasting on stars emitting high energy photons as it rips apart matter

there were two much more subtle regions
the upper arm of the small spiral galaxy NGC 3861b:

and the red smile in this faint irregular galaxy KUG 1140+202A:

*technically not the Doppler effect in this context

Wednesday, August 13, 2014

Leo Galaxy Cluster aka Abell 1367: Part 1 Deep Sky

factoid: Abell 1367 has more galaxies brighter than mag 14 than any other galaxy cluster

the term "deep sky objects" is used by amateur astronomers to denote
objects other than solar system objects and individual stars.
as some may have notice, all of my images since moving have involved objects in our solar system,
most sol itself.  the most distant object being saturn at approximately 8 million miles or 11 a.u. or 1 light hour

at 330 million light years, Abell 1367 goes to the other extreme.
to put things in perspective, the closest star is 4 light years away
the pleiades are 375 light years (ly) away
orion nebula 1500 ly
crab nebula 6000 ly
the black hole at the center of the milky way 27,000 ly
the andromeda galaxy 2 million ly
M51, the whirl pool galaxy 15 million ly
the virgo galaxy cluster 50 million ly

link to full size

most of the dots in this field are not stars, but galaxies each containing billions of stars.
here's an annotated version with galaxies circled
the large circle outlines the galaxy cluster itself which is a bit bigger than my field of view
objects circled with an arrow pointing away are high proper motion stars
more about QSO's later

link to full size annotated

FS102 OLV @ 618.8 mm, 2.15”/px, IDAS LPR filter/astronomiks 12nm SII filter, SX H9/H9C camera
Luminance 120x5 min, RGB 25x20 min, SII 24x20 min
4/24-5/5/2014 Newport Beach, CA

needless to say it took a lot of work to pull the galaxies out of the light pollution in the image

Saturday, July 26, 2014


a solar prominence is typically a structure seen on the edge of the sun against the black background of space.  it often looks like an arch.  it consists of hydrogen plasma held off of the surface by magnetic fields. 

a solar filament is a large dark line seen across the face of the sun.  again hydrogen plasma held off the surface, but over the surface facing the observer, rather than on edge. 

in a sense, they are two sides of the same coin:
the filament absorbs the intense light from directly beneath then re-radiates it in all directions, with only a small amount heading directly on a line to the observer. This is why filaments appear dark on the solar disk. On the edge, we see the weaker emission component of the filament against a dark background.

that being said, i had difficulty visualizing filaments as the same structure. 
this is in part due to the fact that most images which show prominences are processed in order to lighten them compared to the surface to show more detail, so prominences always seem lighter. 

...until i caught a filaprom.  a filament that continues off the edge of the solar disk, clearly showing a dark line arching up over the surface:

2/16/14 newport beach, ca
DMK 51, 2.5x Powermate, Lunt 60 PT B1200
*manually guided on an altazmuth takahashi teegul mount.
took quite some time to process as software would not track well on solar image moving all over the field