astrophotography by bill w

Monday, May 24, 2021

sunspot AR 2824 and the solar frenzy

The sun burst out of its minimum this weekend with a series of explosions on Saturday May 22nd, the likes of which haven't been seen in years. While I missed the burst, I captured images of the offending spot on Sunday--my first solar images in 2 years:

AR 2824 and friends Ha 5/23/21 21:11 UTC

AR2824 Ha 5/31/21 21:21 UTC

Solar Prominences Ha 5/23/21 21:05 UTC

Something lifting off? Ha 5/23/21 21:03 UTC

artistic composite view (exclusion) Ha 5/23/21

The bursts are forecast to hit earth's magnetic field in the late hours of May 25th, potentially triggering auroras. A big bonus for north western viewers staying up late for the lunar eclipse in the wee hours of May 26th.

the accompanying radio bursts were so loud they drowned out a local thunderstorm (Thomas Ashcroft's radio data):

View the dynamic spectrum

listen to the audio

While NASA's Solar Dynamics Observatory recorded a series of flares:

movie

Here's a list of annual sunspot activity over 15 years from spaceweather.com, a great site for solar activity information. showing the minima around 2019 and 2008, confirming an 11 year solar cycle that's been documented for centuries:

Spotless Days
Current Stretch: 0 days
2021 total: 46 days (32%)
2020 total: 208 days (57%)
2019 total: 281 days (77%)
2018 total: 221 days (61%)
2017 total: 104 days (28%)
2016 total: 32 days (9%)
2015 total: 0 days (0%)
2014 total: 1 day (<1%)
2013 total: 0 days (0%)
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
2008 total: 268 days (73%)
2007 total: 152 days (42%)
2006 total: 70 days (19%)
Updated 24 May 2021

Image details:
Ha full disk Lunt 60 PT double stacked
zwo ASI 290MM
FPS (avg.)=39-178
Shutter=0.331-1.78ms
Gain=351 (unity)
East Bluff, CA
5/23/21
21:05-21:11 UTC

Sunday, February 28, 2021

mars wrap up

Mars is all over the recent news with a fleet of space craft arriving:

-NASA's perseverance pulled off a crazy landing with a supersonic parachute (which just sounds cool), followed by a heat shield, then rockets, and finally a sky crane lowering the lander into the dust with the rocket hovering above. NASA video.

-the UAE's Al'Amal (hope) is orbiting the planet and filming.

-China's Tianwen-1 is orbiting, preparing to send down a lander.

Perseverance is loaded with easter eggs including a binary message encoded in the parachute: "Dare Mighty Things", the motto of NASA’s Jet Propulsion Laboratory (JPL) and the coordinates of the JPL visitor's center: 34°11'58.0"N 118°10'31.0"W.

More easter eggs here

You can even follow the perseverance twitter account:

"Hobbies: Photography, collecting rocks, off-roading" 😄

so here's an excuse to process the rest of my mars opposition images. the following sequence shows the south polar cap slowly melting in the martian summer (though some of the change is due to rotation).

Mars 2020
Click for full size

Here's a final shot at shorter focal length from the evening of the great conjunction:

Mars 12/20/2020
wave goodbye

long winded technical imaging stuff:

the right hand image above was captured with a one shot color (OSC) camera. an 850 nm IR filter was used to capture IR frames. how can an IR filter work with a OSC camera? all of the color filters pass IR (this is why you need an IR blocking filter for many OSC cameras). so theoretically a relatively long IR filter will pass IR to all color pixels giving a mono IR image.

unfortunately i didn't realize i needed to uncheck the color balance during acquisition, so the pass-through wasn't uniform by color: it yielded the typical checker board appearance one sees with an undebayered color image. color conversion gave a blue tinted image. each of the "color" images were identical, so a simple color balance gave a mono image. perhaps it was the conditions or the filter, but the debayered IR image offered no improvement in resolution compared to the red filter. which is not my experience with a mono camera, though i've not tested the 850 mono yet.

***will have to try again with the white balance adjusted next season

from a practical stand point IR/OSC images probably don't add much unless there's a major dust storm interfering with surface visibility as in the 2018 opposition.

in a prior post i noted that while using IR as luminance generally improves the contrast/sharpness of the blue surface detail, it loses subtle cloud detail. i note an interesting corollary to that with this image: using IR in place of the red channel will enhance clouds as they appear bluish compared to the background:

Mars 11/15/2020 06:17 UTC
IR-G-B

Image details:

celestron 11" Edge HD

ZWO ASI 290MM

ZWO RGB filters, Baader IR pass "685" nm

30% histogram

firecapture, autostakkert, winjupos, maxim, photoshop

9/29/20 07:35 UTC

2x120 second captures each filter, 400 FPS

gain 351, exposure ~.2 ms,

tried a methane filter for fun which was like a bad IR filter :(

10/11/2020 8:27 UTC

2x120 second captures each filter, 400 FPS

gain 351, exposure ~.2 ms,

10/14/2020 07:48-08:09 UTC

very good seeing

*televue 2x barlow*

2x120 second captures each filter, 200 FPS

gain 351, exposure ~1 ms,

elevation ~60 degrees

11/15/2020 06:17 UTC

ZWO ASI 290MC

ZWO 850 nm IR pass filter

6x120 second captures RGB, 400 FPS

gain 351, exposure ~.2 ms,

Eastbluff

Southern California...

Thursday, December 31, 2020

Fireball 7964-2020 Heralds the Great Conjunction

Here are a my conjunction images.

12/20/2020 note great red spot showing on Jupiter

Great Conjunction 12/21/2020
day of closest approach

You'll note that Jupiter (which has four bright moons) appears to have 5 moons in the first image, but only 3 on the day of closest approach!? In the first, a background star is in disguise as a moon, while in the second, Ganymede is attempting to hide from view as it crosses the surface of the planet (see annotated versions below).

12/20/2020

12/21/2020

The event was heralded by a fireball (bright meteor) seen by thousands. It ocurred at 5:11 PM pacific, less than 30 minutes after sunset with the southern sky still bright blue, making this the brightest I've ever seen. It looked like a firework with sparkles. Scott Young from our astronomy club put it better: "I was looking directly at the planets and the fire ball came from the north and traveled south. It burned up just after falling below the planets. Long streak with lots of fragments and a burst just before the burnout. I'm sure it was an Ursid". About 10 minutes after seeing it, I made a quick sketch as it was hard for me to describe the direction:

you can see why i take pictures :)

There were documented sightings from Santa Barbara to San Diego:

very tall astronomers

It has been labled as event 7964-2020 by the American Meteor Society. More info at links below:

American Meteor Society log of event 7964-2020 -includes video
december meteor forcast
ursid meteor shower

Image Details:

Imaging rig including telescope for telescope for telescope.
hedge obstructs low southern horizon :(

The conjunction images are composites of multiple exposures: short tight crops at high frame rates for each planet. a combined image of the two planets with saturn much more faint relative to jupiter than in the composite. a longer exposure for the jovian moons, still longer for titan, and longest with a stretch for the faint moons of saturn.

Takahashi FS 102 at 820 mm, ZWO ADC, Baader IR/UV block filter, ZWO ASI 290 MC
captures ranged from 0.34 ms exposures at 400 fps to 100 ms at 8 fps
Eastbluff, CA 12/20/20 and 12/21/20

Friday, December 25, 2020

Gas giants 2020 including disturbance in jupiter's NEZ with methane filter

Taking a break from conjunction processing to post these larger images of the gas giants:

Saturn 9-25-2020 03:49 UTC RGB

Jupiter 9-25-20 03:23 UTC
note white dot in the upper band, a disturbance in the northern equatorial zone noted this past summer

Jupiter 9-25-20 03:23 UTC Methane filter
enhancing disturbance in upper atmosphere of NEZ
(white dot upper half)

Methane RGB

Jupiter 9-25-20 03:23 UTC Methane filter as red, green, blue
enhancing disturbance in upper atmosphere of NEZ

Previous post with more information on jupter images with a methane filter:

https://astrowhw.blogspot.com/2019/10/jupiter-methane-filter.html

image details:

celestron 11" Edge HD

ZWO ASI 290MM

zwo RGB filters

Baader methane 889 nm 8 nm bandwidth

sharpened in registax

combined in winjupos

Jupiter: 9-25-20 03:23 UTC

Saturn 9-25-2020 03:49 UTC

no sign of the hex :(

fair seeing

Eastbluff

Southern California

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.