comet NEOWISE C/2020 F3

Here it is over Irvine from my house (click for full size):

Comet NEOWISE C/2020 F3 over Irvine 7/12/2020

Comet NEOWISE C/2020 F3 7/12/2020

Comet NEOWISE C/2020 F3 7/12/2020

Observations:

the comet was not visible to the unaided eye.  the contrast in binoculars about matched the wide field image (canon 15x50 IS).  it started fading markedly at 5:00 AM and was lost to view at 5:15 AM

image details:

after days of getting up painfully early to clouds, i caught it this morning.  the sting of the early rise was mitigated by the fact that the 10 degree arc of horizon visible from my bedroom balcony aligned perfectly with the comet.

Nikon D-60, AF-S DX NIKKOR 55-300mm f/4.5-5.6G ED VR, 

wide: f/4.5 @ 55 mm, ISO 800, 3.0 sec, 4:58 AM

narrow: f/5.6 @ 300 mm, ISO 800, 3.0 sec, 4:43 AM

7/12/2020

Eastbluff, CA  

The fainting of Betelgeuse

Will Betelgeuse blow? Will Taurus gore Orion? Read below:

Recently, the star Betelgeuse (orange "shoulder" of Orion) faded from the 10th brightest in the sky to about 26th.  No longer a beacon, it faded almost to the level of Orion's belt, and well below the level of blue Rigel (Orion's forward foot).  This is the most faint ever recorded (observes have been tracking it with the use of reference stars for ~200 years).  Many in the astronomy field were excited by this as it might be the harbinger of a supernova in our "back yard", an event not witnessed in living memory.

The relatively dark image of orion below was processed to preserve relative brightness and color.  you may need to darken the room and/or adjust your monitor to see it well.  pretend you're looking at stars...

Orion linear stretch to preserve relative brightness.  Note that orange Betelgeuse (upper left)  is closer to the brightness of the belt stars,than bright Rigel (lower right)

stretched version showing orion nebula in the sword below the belt

Here's my last attempt from 2005. Is Betelgeuse brighter?

full constellation just for fun (2/26/2020)

If Betelgeuse were to go supernova, it would likely be so bright it would be easily visible during the day.  It might eventually leave Orion's shoulder with a blood red nebula the size of the full moon: as if Taurus' horn gored Orion's shoulder (Pamela Gay, Astronomycast).

Why might this happen?  Betelgeuse is a cool red supergiant star (diameter the size of Jupiter's orbit) who's brightness varies periodically with time.  The variation in brightness is due to change in the actual size of the star. For reasons not entirely clear, the star periodically shrinks and expands, creating a smaller or larger surface from which light shines.

The thing about supergiant stars is that they are known to go supernova.  They "burn" (fuse elements) so fast, that they eventually run out of fuel (actually they fuse elements up to the size of iron which doesn't like to fuse and stops the process).  When that happens, the light pressure holding the stellar surface out disappears and the star gravitationally collapses until...BAM supernova leaving a tiny neutron star in the center (like the crab nebula).

So perhaps the fainting was due to a pre-supernova collapse...
To the dismay of some, Betelgeuse began to brighten again in late February 2020.  A Spectrographic study indicated that the dimming was due to intervening dust expelled from the star.  

Addendum: Subsequent work suggested it was giant sunspots instead...

a few more gems in orion:

Orion Nebula (Ha-OIII) (1/2009) Click for full size

Flame nebula in orion with belt star alnitak blazing away (12/2006)

Horsehead nebula-blue glare left caused by Alnitak (off frame) in orion's belt. (HaLRGB 12/2007)

image details:
Orion constellation
Nikon D60
stock lens (18-55) @36 mm f/5.3
12 x 5 sec
Eastbluff, CA 2/26/2020

2005
Canon Digital Rebel 300d
stock lens

Orion nebula
FS60C f/4.2 FR Baader 8.5 nm Oiii/CS 10 nm Ha filters, H9
Ha 35x5 min + 26x30 sec, Oiii 29x5 min +33x30 sec
12/5,8,9/2008
los alamitos, CA bortle white skies
poor seeing fair transparency for area

Flame nebula
fs102 idas LPR H9C
30x5 min
it was tough controlling alnitak in processing
12/2006
los alamitos, CA bortle white skies

Horsehead nebula
FS 102 @~f/6 (618mm) with TOA reducer; IDAS LPR, CS 10 nm HA; h9/h9c; guiding with toucam on celestron f/5 80mm wideview.
rgb 83x5 min, luminance 66x2 min, HA 19x20 min
12/10-16/2007; los alamitos, CA; usual bortle white skies; several nights of above average transparency (for the region); fair to poor seeing HFD 3.8-4.7

A black hole on Neptune?

You'd think it would be on uranus, but there's a black hole on neptune: the Great Dark Spot is thought to be related to a storm, similar to the persistent great red spot on jupiter. there's also occasional cloud activity on the surface of neptune.  both are extremely difficult to detect as it's quite distant.  

Here's a shot of neptune on the same night i shot uranus, using the same processing techniques.  
Definitely a bit of a stretch, but with a little imagination you can see a subtle dark section in the center and a white patch just below and to the right:

Neptune 10/27/2018 06:17 UTC IR-RGB

also seen to the lower right is neptune's moon triton.  

I'd say the white patch is more convincing, but can't call either more than wishful thinking/artifact at this point.  If nothing else, it's a nice shade of blue ;)



Imaging details:
camera ZWO ASI 290MM with ZWO RGB filters
Baader IR pass 685 nm
celestron 11" Edge HD
East Bluff, CA
10/27/18 06:17 UTC
120 second captures, 2x each filter (3 for IR)
gain 456 , exposure ~51 ms red, 19 ms green, 23 ms blue, 100 ms IR 685 <30% histogram
upsampled x2 in autostakkert, derotated in winjupos.
color balance on triton
composite image to bring in triton (present even on short exposures, but faint)

clouds on uranus

what better follow up to methane on jupiter than clouds on uranus? 

prior blog entry: "there's not much to see visually.  bluish-green, it can be seen with the unaided eye in dark locations.  At high power it can be seen as a small disk rather than a dot.  A monster telescope or camera might detect several moons, and possibly faint cloud formations..."

to my surprise, an IR filter was able to bring out cloud cover on the upper half:

Uranus IR-RGB 10/27/2018 08:52 UTC

have to try a methane filter on this one ;)



Imaging details:
camera ZWO ASI 290MM with ZWO RGB filters
Baader IR pass 685 nm, Astronomik IR pass 807 nm
celestron 11" Edge HD
East Bluff, CA
10/27/18 8:52 UTC
120 second captures, 2x each filter (only one for IR 685)
gain 456 , exposure ~13 ms red, 4 ms green, 6 ms blue, 130 ms IR 807 30% histogram
upsampled x2 in autostakkert, derotated in winjupos.
color balance eyeballed ;)
(actually set the white point to the clouds)


here's the straight RGB for the purists:

Uranus RGB 10/27/2018 08:52 UTC

References:
interesting articles by Christophe Pellier on the spectrum of uranus and implications for IR filters:
https://www.planetary-astronomy-and-imaging.com/en/uranus-spectrum-commented
https://www.planetary-astronomy-and-imaging.com/en/filters-uranus-spectroscopy

mercury transit 11/11/2019

managed to catch the tail end of the mercury transit through clearing clouds and fog.  fortunately, the sun is at solar minimum, so there was nothing on the face to upstage the tiny dot. The images were shot with dedicated solar a hydrogen alpha telescope.

Animation (thru passing clouds)

A different perspective

Ha composite

Activity lower right

Image details
Ha full disk Lunt 60 PT single stacked
zwo ASI 174MM
FPS (avg.)=81
Shutter=1.978ms
Gain=50 (12%)
East Bluff, CA
11/11/2019
17:36-18:04 UTC