Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Thursday, November 11, 2021

Venus in infrared and ultraviolet 9/13/21

Here are several images of venus captured with infrared and ultraviolet filters. UV  light shows cloud structure which cannot be seen in the visible spectrum while IR in this case gives a sharper image, but no cloud detail:

Venus IR 9/13/21

Venus UV 9/13/21

Venus UV (colorized) 9/13/21

Venus IR as red, UV as violet 9/13/21

the seeing was fair to poor.  my intent this day was to image mercury, but i could not locate it during daylight with my overloaded mount.  here are the raw stacks with two different IR pass filters one at 685 nm, the other 850 nm.  the 850 being further into the infrared is generally preferred for mercury or poor seeing conditions, the latter being the case here:

Venus IR (raw stack) 9/13/21


Image details:
camera ZWO ASI 290MM 
filters: Baader IR pass "685", ZWO IR pass 850, Baader U-filter bw 320-380nm
celestron 11" Edge HD, no barlow
East Bluff, CA
9/13/21 00:13-02:17 UTC

685 filter:
FPS (avg.)=212
Shutter=0.101ms
Gain=234 (39%)
850 filter:
FPS (avg.)=20
Shutter=1.351ms
Gain=234 (39%)
UV filter:
FPS (avg.)=201
Shutter=4.952ms
Gain=351 (58%)



Sunday, November 7, 2021

solar stuff

Solar Prominence Ha 
8/15/21 18:20 UTC

 
Solar Prominence Ha 
8/15/21 18:20 UTC
Exclusion

Solar Prominence Ha 
8/15/21 18:32 UTC
smaller prom from the side of the disk (rotated up)

There was a lot of excitement in the solar community this week due to a series of solar outbursts directed at the earth, some massive.  I actually caught the beginning of one visually on 10/28, but did not take pictures.  according to spaceweather.com a cannibal coronal mass ejection (fast moving coronal mass ejection, running into a slow moving one) hit the earth creating auroras visible as far south as 39 N in central california; detectable in cameras as far south as joshua tree. 

it was of course cloudy here so i missed it all as well as the taurid meteor shower and the new moon :(

The images above show a pretty big solar prominence i captured on 8/15/21 and have absolutely nothing to do with the events described ;)


Image details:
Ha Lunt 60 PT double stacked
zwo ASI 290MM
manual tracking on alt-azm mount
20 sec captures
FPS (avg.)~93-178
Shutter~0.331-2.283 ms
Gain=351 (unity)
East Bluff, CA
8/15/21 18:20, 18:32 UTC

Saturday, September 18, 2021

Jupiter got smacked

the astronomy community was abuzz last week when an amateur astronomer in Brazil captured video of a  bright flash as a meteor estimated at 100 m crashed into jupiter.  At least 10 other observers independently observed the event, making it the most observed impact on jupiter to date; the eighth recorded since the first was observed in 1994.  More information can be found in this sky & telescope article

Had the meteor struck earth it would have been equivalent to 34 megatons of TNT (hiroshima was 15 kilotons).  Jupiter's massive gravity is thought to protect earth from many of these collisions.

Despite the fact that observers were not able to find any residual storms (which have been sighted after prior impacts), i decided to check out the impact site with a methane filter.  unfortunately, the Jupiter Central Meridian calculator cited in the article is now defunct and spat out the wrong data--so i completely missed the site (holy homophones).  nevertheless i got some colorful pictures of jupiter:

Jupiter 9/16/21 04:38 UTC.  RGB left, Methane center, Methane as red, GB right

Imaging details:
camera ZWO ASI 290MM with ZWO RGB filters
Baader methane 889 nm 8 nm bandwidth
celestron 11" Edge HD, no barlow
East Bluff, CA
90 second captures, 2x binning for methane
gain 351, exposure ~0.6-1.0 ms, 30% histogram, ~280 fps
methane exposure 375 ms, 2 fps

Tuesday, September 14, 2021

a rocket at night: falcon 9 launch 9/13/2021

visually it was a spectacular event, there was something surreal about seeing the long bright orange rocket plume slowly rising up through the trees.  it looked very...well rocket-like.  perhaps we'll be used to it in years to come.  perhaps residents closer to vandenberg are already used to it--tired of it?

 Unfortunately, my images were pretty much a bust, but here are a few salvages, the best from my cell phone:

Falcon 9 from Coastal Peak Park 9/13/2021



image details:
Samsung Galaxy Note 9
f/1.5, 1/4 sec, 4 mm
Nikon D850
Nikon Nikkor AF-S DX Telephoto Zoom 55-300mm f/4.5-5.6G ED VR
f/4.5, 2 sec, iso 5000, 55 mm

much processing in photoshop to correct star trailing due to camera shake as my remote wasn't working.  





Sunday, July 25, 2021

venus mars (moon) conjunction 2021

The conjunction of venus and mars on ~7/12/21 made it to many astronomy calendars, including mine.  Planetary conjunctions are typically scenic visual events for the unaided eye.  That being said, this one was pretty unimpressive (i could not see mars), but it gave me an opportunity to practice/learn with a conventional camera.  

Here it is the day before closest approach with the moon nicely aligned (Mars is the tiny dot just above the tree on the left):

mars-venus (moon) conjunction 7/11/21 20:38 PM pacific
Close up of the red planet

Here's closest approach the next day. mars is a tiny speck just to the left and below venus, lower right:
mars-venus conjunction 7/12/21 20:33 Pacific 


Image details
nikon D850
AF-S DX NIKKOR 16-85mm F3.5-5.6G ED VR 
eastbluff, CA 7/11,12/2021

for the bottom image i captured close up videos of the moon at 2 exposures, one very bright with earthglow, the other capturing the bright detail, but no earthglow.  I made a composite of the two, preserving detail and showing earthglow, and placed it in the final image in which the moon was clipped...
...it made no difference at the scale in the image above, but it was an interesting exercise :)

Monday, July 5, 2021

rising moon refracted

i decided to image the last supermoon of this year as it rose from the beach at corona del mar:

Moon rise 6/24/21 Corona Del Mar

you'll note it's quite distorted.  as the moon is rising, the light is traveling tangentially thru a thick layer of atmosphere which causes distortion as turbulence bends (refracts) the light.  on this particular evening there was so much distortion, it was impossible to get a round looking moon as it rose.  there are basically two approaches to this problem: 1. wait for the moon to rise higher and capture a sharper image or 2. embrace the distortion.  To put it another way (as alan smallbone often writes): "One photo out of focus is a mistake, ten photos out of focus are an experimentation, one hundred photos out of focus are a style."

here's a great shot rob middleton took with me at cdm, showing off the zoom of his nikon coolpix P900 camera:

love the iconic palm tree next the gigantic deformed moon. 

Here's the other approach: an image captured as the moon rose higher.  it's a composite of a long exposure for the landscape, and a close up video stacking and processing 1,000 extremely short exposures:


more "experimentation":

Here's an animation of the rising moon.  it almost looks like it's passing thru an inversion layer:


Interestingly, when you first see the moon rising, it's actually below the horizon--the rays are bent by the atmosphere, changing the apparent position.  Here's a website explaining all sorts of related phenomena, including the green flash: http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/mirage.html

This close up shows a green fringe at the top and red at the bottom, again due to atmospheric refraction:


Another gigantic moon and palm tree shot from rob:


a few test shots from the night before. had to wait for the moon to clear the cloud layer (it was still pretty super):

pastel moonrise 6/23/21




Image details
nikon D850
AF-S DX NIKKOR 16-85mm F3.5-5.6G ED VR 
6/24/21
corona del mar, CA

rob middleton's images:
nikon coolpix P900



Sunday, May 30, 2021

lunar eclipse 5/26/21

with clouds forecast, i set my alarm for 4 AM and woke to see the sky clearing.  with some ambivalence i dragged myself out of bed, grabbed the camera set up in the garage and managed to catch the eclipse just as the moon cleared the clouds, watching it set again into a cloud bank.  
lunar eclipse 5/26/21 4:15 AM pacific
clearing clouds

lunar eclipse 5/26/21
composite image
cropped bright lights

partially eclipsed setting into cloud bank


Image details
nikon D850
AF-S DX NIKKOR 16-85mm F3.5-5.6G ED VR 
5/26/21 ~4 AM 
east bluff, CA

all highly cropped, probably should have used longer focal length lens as the wide star field is unimpressive with this level of light pollution