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:

webb deepsky.com 

NED database entry for NGC 5371

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

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.  

our galaxy

the milky way has been on my to do list for a while. here's a shot from the desert:

Milky Way 7/21/2020, Sheep Hole Valley Wilderness,  Mojave Desert

my best to date, though somewhat anticlimactic as it was a 20 second afterthought while shooting comet neowise

another edge on galaxy for comparison:

NGC 3628 35 million light years away
2007

previous attempts:

Hetch Hetchy, stacked images, dark skies old out of focus DSLR
2019

wide field stack from light polluted skies
2018 webcam

first ever 2004.  the faint "smoke" coming out of the chimney is the milky way, totally by accident

image details:

sheep hole valley wilderness, mojave desert, CA

7/21/20 10:00 PM pacific

nikon D850

wide field: Sigma 15mm F2.8 EX DG fisheye

20 sec ISO 25,600

NGC 3628

4/12-17/07

los alamitos, CA

N8 GPS, F/6.3 FR @~1280mm, SX AO @~4Hz, IDAS LPR, H9C

45x20 minutes

7/7/19 

Hetch Hetchy, Yosemite National Park, California

Nikon D60

stock lens (18-55) @18 mm f/3.5

sky watcher star adventurer mount (tracking stars)

88x30 sec ISO 400

even with dark subtraction, there was significant amp glow, hence the desaturation.

8/12/18 to 4 AM 8/13/18 AM PDT (until clouded out)

Eastbluff

Southern California

ZWO ASI 290MC

stock fisheye lens with home made cardboard dew shield and kendrick dew heater

Shutter=20.0s

Gain=100 (16%)

20 second exposures continuously

2004

Canon digital rebel

stock lens

NEOWISE C/2020 F3 from the desert

Here are my NEOWISE images from the Mojave.

First, a starlink photobomb (a/k/a) Elon plays space invaders:

comet NEOWISE C/2020 F3 animation, series of 3 second exposures 7/21/20

close up stacked image (removing star, comet, satellite and plane trails):

wider view with a bonus early perseid:

still wider (fisheye):

Thanks to OC astronomers member and renowned astrophotographer Wally Pacholka for the inspiration:

"Gents With a comet like Neowise dropping by only every 20 years or so, can I encourage folk to see and photograph it from a dark location so you can enjoy it’s true beauty. Do whatever is necessary to leave Dodge and get out of town."

his NEOWISE images are available here:

https://astropics.com/comet-neowise/

Observations/Travelogue 

taking a tip from wally, i headed out to amboy crater, in the Mojave desert 

Amboy Crater

an ideal location due to the absence of light pollution in the northwest where the comet would be setting:

lightpollutionmap.info

after a bit of reconnoitering, i opted for a location a bit south of the crater then made a few minor adjustments for local wild life:

snake spoor

 

visually, the comet was spectacular, spanning 5 degrees of sky (10 degrees with binoculars) almost as bright as the milky way, though more focal.  

photographically, saturday night (7/18/20) was a bust.  it seemed my 10 year old nikon D 60 which was fine in light polluted skies was not up to dark skies in 100 degree heat (but it was dry heat)

A rare case where the camera is less sensitive than the eye (or cellphone):

Nikon D60 stacked and processed

cellphone:

Samsung Galaxy Note 9 single frame

having flailed with my Nikon D60 Saturday night, i went back out to the desert Tuesday night to try again, armed with a better camera (rented nikon D850) and more glass. 

 

This time at the sheep hole valley wilderness (south east of amboy) just north of eastern joshua tree.  
the sheep hole mountains on the left of the widefield are shielding the barstow (and 29 palms) light dome which i assume can be seen from much of joshua tree when looking NW:

Image details:

sheep hole valley wilderness, mojave desert, CA

7/21/20 ~9:20-11 PM pacific

nikon D850

close up AF-S NIKKOR 85mm 1:1.4G 

10x stack 3 seconds ISO 25,600!

stacked in deep sky stacker

intermediate: AF-S NIKKOR 18-55mm 1:3.5-5.6G at 18 mm

30 sec ISO 25,600

wide field: Sigma 15mm F2.8 EX DG fisheye

20 sec ISO 25,600

lens distortion correction in photoshop

spent too much time stacking images which wound up worse than single shot except for the close up.  

super high ISO, blew out the star colors, but stacking with lower ISO images didn't work out for me.  

NEOWISE 7/21/20 5 sec ISO 6400, better star color and green at comet core

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