Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Sunday, December 13, 2020

winter is coming...a geminid

Here a few wide fields and my attempt at imaging the classic winter meteor shower, the geminids (night before peak which was clouded out).  

Orion Rising...winter is coming.  when you see orion rising in the early evening, winter is on the way.  note Betelguese (red "shoulder" upper left) no longer faded:

Orion rising 12/12/20
have to do something about that fence :(

here are a few hours worth of star trails.  only one sad meteor, can you find it?

Star trails 12/12/20

close up:

a geminid

Localized:

a geminid 12/12/20



image details:
12/12/20, eastbluff, CA
Bortle white skies
nikon D850
Sigma 15mm F/5 EX DG fisheye
30 sec, iso 200

Saturday, December 5, 2020

Uranus 12/1/2020 07:15 UTC

Uranus 12/1/2020 07:15 UTC IR(685)-RGB
Planetary north up


Image details:
camera ZWO ASI 290MM
ZWO RGB, Baader IR pass 685 nm filters
celestron 11" Edge HD
East Bluff, CA
12/1/20 07:15 UTC
fair seeing 3/5 on clear dark sky clock
120 second captures, 2x each color filter, 3 sets of 3 for IR 685
gain 456 , exposure ~12 ms red, 5 ms green, 8 ms blue, 31 ms IR 685 30% histogram
upsampled x2 in autostakkert, derotated in winjupos.
initial wide field capture with moons key to alignment in winjupos.  
oriented planetary north up.  
color balance-eyeballed ;)
tried a methane filter...not enough signal

RGB only:
Uranus 12/1/2020 07:15 UTC RGB

Saturday, November 28, 2020

Random moon pics

Here are a few random pics of the moon. i'm not much of a lunatic, can't really name craters etc.  just grabbed a few pics when it caught my eye while setting up image sessions.  

lunar halo 11/29/20

lunar halo close up composite 11/29/20

a nice crescent captured with my deep sky camera on a 4" refractor while imaging hickson 68.  single shot, no stacking:

Moon 4-26-2020-03:30-UTC

Next a moon walk on the terminator during a waxing gibbous with a high magnification planetary set up:

Moon 9/25/2020 03:05 UTC (click for full size)




mosaic, 9/25/2020 03:05 UTC (click for full size moon walk)


image details:
lunar halo
nikon D850
wide field: Sigma 15mm F2.8 EX DG fisheye
close up: AF-S DX NIKKOR 16-85mm F3.5-5.6G ED VR 16 mm
11/29/20 east bluff, CA

crescent
FS102 OLV @ 627.8 mm,
Starlight Xpress Trius 694, 1.49"/Pixel
ASA DDM60
4-26-2020 03:30 UTC
east bluff, CA

close ups:
camera ZWO ASI 290MM
Baader IR pass "685" nm
celestron 11" Edge HD
ASA DDM60
9/25/2020 03:05 UTC
east bluff, CA

Tuesday, October 20, 2020

Mars opposition 2020

 Here's mars shortly after 2020 opposition:

Mars RGB 10/14/2020 0758_5-UTC


Mars IR-RGB 10/14/2020 0758_5-UTC

Note that the bottom image, which uses IR as luminance gives sharper detail and contrast for the dark surface structures, but loses the detail at and around the southern polar cap as well as the bight bluish cloud? near the northern pole (upper right, which was visible in the eyepiece)

This year's opposition was much better than 2018 visually, as there was no dust storm obscuring the surface and it occurred at higher elevation for northern hemisphere observers.
https://astrowhw.blogspot.com/2018/07/mars-closest-approach-7312018.html

Image details:
10/14/2020  07:48-08:09 UTC
celestron 11" Edge HD
televue 2x barlow
ZWO ASI 290MM
ZWO RGB filters, Baader IR pass "685" nm
2x120 second captures each filter, 200 FPS
gain 351, exposure ~1 ms, 30% histogram
firecapture, autostakkert, winjupos, maxim, photoshop
elevation ~60 degrees
Eastbluff
Southern California


Sunday, September 20, 2020

Compact Galaxy Group Hickson 68 and a supernova

Hickson Compact Galaxy Group 68 is a tight group of galaxies 100 light years away in the constellation Canes Venatici visible in late spring (click on image for full size):
Hickson 68 5/2020


Brighter version with more faint galaxies and more noise (click on image for full size):
Hickson 68 5/2020


the lower two "bright fuzzies" in the image are interacting, surrounded by a faint glow of stars being traded:
Hickson 68 5/2020


the bright galaxy to the left is NGC 5371, also 100 million light years away.  it's likely gravitationally related to the group.  

100 million years or so ago, a star went supernova in NGC 5371.  the photons reached us in January 2020.  the supernova remains detectable in this image
NGC 5371 with SN 2020bio 5/2020

my first supernova capture, totally by accident.  

nebulae in the outer arm of NGC 5371 are emitting red light due to hydrogen emissions--the hydrogen alpha line.  my initial Ha images failed to show any Ha enhancement.  it occured to me that the redshift of the receding galaxy shifted the Ha emissions out of the range of my 5 nm filter. so i switched to a 12 nm filter to capture nebula.  
Ha image showing bright nebula in the lower right spiral arm of NGC 5371:
Hydrogen alpha enhancing nebula in the lower right right arm of NGC 5371

many tiny background galaxies and quasars:


i imaged this group back in 2006 with a larger scope (click on image for full size):
Hickson 68 5/2006

the field was too narrow to include NGC 5371 so it was on my reshoot list.  
didn't really plan on shooting it this spring, but after creating a pointing model with a refractor on my mount, the sky was relatively dark (possibly related to covid lock down) and the group ideally situated.  started this during peak covid lock down in April. my bortle white skies seemed about .5 mag darker, which i attribute to less particulate from car traffic.  

image details:
FS102 OLV @ 627.8 mm, 
Starlight Xpress Trius 694, 1.49"/Pixel
astrodon LRGB E-series filters
switched from astrodon 5nm Ha, to astronomik 12 nm Ha 
ASA DDM60
L 125x30 sec RGB approximately 90 x 90 seconds each channel
Ha 36x5 min, RGB 20x1 minute each channel
4/24-5/27/2020
Bortle white skies
Eastbluff, CA

2006 version 
C8, SX H9C

on the red shift of NGC 5371:
z=0.00853 
so Ha emissions will be shifted 656.28 nm * .00853 = 5.6 nm, to 661.88, potentially out of the range of a 5 nm bandwidth filter centered at 656-ish (656+5/2=658.5), and even at the edge of a 5 nm NII filter centered at 658 (658+5/2=660.5), not far enough for my wide 12 nm SII filter centered at 672 (672-12/2=666😈).  a shopping opportunity! now it's right at the edge of my new 12 nm band width Ha filter centered at 656 (656+12/2=662) 😎

references:

Monday, September 7, 2020

saturn and jupiter, preparing for the great conjunction

a late start on the gas giants this year due to comet neowise hoopla, here's my first of the year, a quick shot thru my smaller SCT:

Jupiter 8/26/20 6:01 UTC

Saturn 8/26/20 6:15 UTC


A GREAT CONJUNCTION of jupiter and saturn this december is getting hyped.  every 20 years or so, jupiter laps saturn in it's orbit, which means for a brief period they are very close together visually.  This year, on December 21, they will be separated by only 6 arcminutes--the closest conjunction in 400 years.  this means the two can be seen in the same telescopic field.  Their moons will almost overlap.  

OK realistically speaking, the planets will both be very low in the sky at this time of year. therefore, the seeing will be poor, limiting the ability to get fine detail.  furthermore, the field of view required to capture all the objects will be too large to portray fine detail.  that being said, the juxtaposition will probably look pretty cool to veteran astronomy buffs who are not used to seeing the two objects in the same field.  

Visually, you can "prepare" for the conjunction, by watching the two planets grow closer together in the evening sky.  photographically, i'll have to work to get a planetary imaging system with a large field of view.  i may actually use a refractor ;)

More information:

Great conjunction at EarthSky

Wikipedia link



Image details:
nexstar 8 GPS (altazimuth)
ZWO ASI120MC
90 seconds
eastbluff, CA 8/25/20



Tuesday, August 25, 2020

a perseid

back in eastbluff i decided to try out my D850 on the perseids on 8/11/20.  an extremely bright meteor streaked like lighting across the sky as i set up my camera at round 10 or 11 pm...only caught one with the camera over the next 3 hours:

Perseid 8/11/2020



close up





image details:
8/11/20, eastbluff, CA
nikon D850
Sigma 15mm F/5 EX DG fisheye
30 sec, iso 200
focusing the D850 with live view zoomed in and super high iso was a joy, giving tight stars on close up (though distorted by the fisheye) compared to the D60

this contrasts with my dark sky neowise images with twice the aperture and 100x greater ISO.  the image would be solid white if i tried that under polluted skies.