Halloween special, Aurora, galaxies, a snoot on comet C/2023 A3, and Saturn's moons

31st October - Halloween Special

All Hallows eve, the night when all the saintly souls go to bed early prior to their annual piss up, and ghosts, demons and lost souls take the opportunity to do what ghosts, demons and lost souls actually do.
Let's see what's out there:

THE GHOST OF CASSIOPEIA
Ooooooh, what's this....

Could it be the spirit of a young girl taken too early from her earthly life, and now running towards you with arms outstretched?
Could it be a bloke with a sheet over his head?
Or could it be an HII region in Cassiopeia a mere 550 light years distant?
Here it is in a wider field of view.
(Click/tap to big).

The bright start is Gamma Cassiopeiae (the middle star of the familiar W shape of the constellation), magnitude 2.1. It is the light from this star being reflected from the nebula that makes it easily visible in the image from my non-astro camera.
In the image you can see more nebulosity in the top left. This is all part of the same thing, images more sensitive to the HII emission line show a continuous nebula extending over 2 degrees of arc (compared to the 0.5 degrees in this image). 2 degrees would equate to a nebula size of about 19 light years.
(Ignore the odd dark thing in the bottom right corner - this is a flat frame issue - or could it be the work of sprites?)

THE GHOST OF MIRACH

Mirach is the central of the three bright stars of Andromeda, At magnitude 2.0 it's just marginally brighter the Gamma Cassiopeiae. Less than 7 arc minutes away is an elliptical galaxy (NGC 404) about 10 million light years distant.
(Click/tap to big).

10 million light years is close for a galaxy, but not close enough to be part of our local group apparently.
That wasn't scary at all. Ghost in this context means that when observing this thing visually, the galaxy looks like a ghost image of Mirach produced by a defective eyepiece (I guess).

Up next....

In the first quarter of the 20th century, American astronomer E.E. Barnard produced a catalogue of Dark Nebula, nebula visible due simply to the fact that they obscured the expected star background. Most (all?) of these will be in the plane of the Milky Way, where there is a star background to expect.
Here's one (Bernard 150) in the constellation of Cepheus.

I had in mind a caption for this...
"Christ, my arse is on fire again!".
The above image (which you can't big) may not justify this. You get a better idea of my thought process by looking at this rather excellent amateur image of the same part of the sky by Graham Winstanley from the BAA website.
Were you (or anyone else) to find yourself in a 'smouldering posterior" situation, I don't think trying to run away from said object is likely to produce the required result.
That's by the by, the burning question for this blog is what demonic mischief could have produced the initial ignition?

That's it for the Halloween special. Sleep well.

(Images acquired between 19:16 and 21:48 on the 31/10/24. Image processing, and the text for this blog, generated during the safety of All Saints Day.)

17th October 2024 - Comet C/2023 A3 (Tsuchinshan-ATLAS) again - the snoot fades!

The 17th had long been predicted a clear night, and C/2023 A3 was going to be high enough and south enough for me to see it from the telescope pier in the garden. Time to get the big 'scope out for some close in snoot images. (See the image from the 16th)
The images were a disappointment. Here's a much reduced single frame.

Not so much a snoot, more snoot remnants. Remnants pronounced as per Frank Zappa in the introduction to this song.
By happy coincidence, the introduction also contains the word snoot! The link, if it works, should take you to YouTube, so, see you later.

Oh, welcome back.

That's probably the last image of this comet I'll take for a while, here's a brief summary.
On the 11th it was 70.9 million km away, travelling at 57.3 km/s. It was only 11 degrees away from the Sun, so would have to have been super bright to be seen, I couldn't see it.
On the 12th it was 70.6 million km away, travelling at 56.4 km/s. It was now nearly 16 degrees away from the Sun, I thought there might have been a chance to see it, but couldn't find it.
My first pictures were on the 14th. It was 72.3 million km away, travelling at 54.6 km/s. 25 degrees away from the Sun, this was a naked eye visible comet, just.
My best pictures were on the 16th. It was 76.5 million km away, travelling at 53.0 km/s. 33 degrees away from the Sun, but I could no longer see this with the naked eye.
On the 17th it was 79.6 million km away, travelling at 52.2 km/s. It was now nearly 37 degrees away from the Sun, and not naked eye visible so far as I was concerned. Nice binocular views though.
(Note over this period the comet brightness has more to do with its increasing distance from the sun (80.6 to 97.1 M km) than it's distance from the Earth.)

Let move on to some planetary imaging.....
A nice picture (for me anyway) of Saturn from around 21:00. As per the discussion from the 28th July, the rings have widened quite a bit since then.

You may have noticed that my Jupiter images are peppered with its satellites (the four Galilean ones anyway), and this never seems to happen for my Saturn pictures. Well, here are three of Saturn's moons:

Titan is the second biggest moon in the Solar system, with a diameter of 5152 km it is not much smaller than Jupiter's Ganymede at 5268 km (our moon - 3745 km). Rhea and Tethys are not so big. This is the first time ever (!) I have seen these last two either at the eyepiece of, or in an image from, a telescope of mine. I was almost shocked when they appeared during the processing (never saw them while I was taking the images). You'll notice Saturn is a tadge on the over-exposed side to get this image.

Given the quality of the Saturn image, the Jupiter images between 23:47 and 01:10 on the 18th were a bit disappointing. (At the start of the Jupiter imaging I had to recover from an "Oh dear, I seem to have accidentally disconnected the dew heater power supply for ages" situation).
The first animated gif shows the rotation of Jupiter over the hour and 20 minutes of imaging.


The second the gradual dimming of Io, as it creeps into the shadow of Jupiter (spanning about 5 minutes).

The last image of this sequence is held for a few seconds, you can see that Io is still being faintly illuminated by light coming round the edge of Jupiter. At the time I thought it had completely disappeared at that point.

16th October 2024 - More Comet C/2023 A3 (Tsuchinshan-ATLAS)

I was lucky in terms of breaks in the cloud cover on the 14th, and also again on the 16th. Here's the resulting pictures:
The small(ish) image here is a stack of 6 5 second images, largely unprocessed after stacking. This is a cropped image, but there is still some obvious vignetting at the top. I did not take any flat frames, so I reverted to software to get rid of this.
If you click/tap the image to big it, you go to a version which includes that processing. The vignetting has gone, but at the expense of curious grayness in the top half of the image.

Looking at the big image, it's noticeable that this comet displays something I haven't been aware of before - an anti-tail, i.e. a "thin" trail of matter pointing from the comet TOWARDS the sun. I don't like the term anti-tail, two words with negative connotations, which doesn't suit my joyously optimistic personality. I'm going to call it a snoot.
Here's a bit of the big image, cropped around the snoot!

Wowser - a snoot!
If you've clicked the image to see the bigger version you'll also have noticed that the tail is long! I would argue it goes off image. That's nearly 9.25 degrees, or half the height of Orion.

Sadly, so far as I was concerned with my old mans eyes, this was no longer a naked eye visible comet.

A couple of other things about the last image (bigger version - not the one you see just above). It contains the path of an artificial satellite to the right of the comet. There are five 'strokes' of the satellites path, each corresponding to how far it moved in a single image, and each stroke is offset a bit because the images are aligned on the comet, and the comet was setting. There are only five, and not six, because there is a big gap between the first five images and the last one. As much as possible, I did not include images with cloud obscuring the snoot!
Secondly, if you look towards the bottom right corner of the image, you will see two stars, one of which is oddly fuzzy. It is not a star, it's the globular cluster M5, which featured in the best of 2023 images, see that image here.

14th October 2024.

My first pictures of Comet C/2023 A3 (Tsuchinshan-ATLAS)

As mentioned earlier in this post (below), I was a tadge disappointed at my two previous attempts at finding this comet. Found it this evening!
You can click/tap to big both these images.

The set of images making up the first picture were taken at 19:00, in a still brightish twilight. The second set at 19:15, when the sky was a bit darker, but the comet a bit lower, with rapidly approaching cloud. The second image has been somewhat over-processed, in an attempt to see as much of the tail as possible.
The tail definitely goes beyond the 'bright' star above and slightly to the left of the comet. The separation of these two was about 3 degrees at the time (just bigger then the width of Orions belt). It possibly extends another 3 degrees beyond this.
The comet was naked eye visible, just about, once found it was easy to see it was there, but it took some finding.

10th October 2024.

The return of Aurora night.

Remember 10th May 2024, with 360-degree aurora, 10th October was similar, but different. It never made the 360-degree category, but by late in the evening there were some spectacular views overhead.
First up some Sony camera images. These are the last image I took with this (at just after 22:00), and the first (at 19:35).
You can click/tap to big both these images.

The display just improved by the hour, from a naked eye point of view, it started out with thoughts of "oooh, that's a bit redder than normal!", and ended up with the word "Wow" crossing my mind.
Here's a few click to change images.
The first is 7 pictures, separated by approximately one minute, from around 20:00.

The second is 3 pictures, separated by approximately three minutes, from around 21:30.

You can see a white lumpy thing moving about in the garden which is the telescope mount in the process of being set up.
The third is just two pictures a minute apart at around 21:45.

You will notice the telescope is now on the mount, soon to be followed by the Sony camera (more on this later). So, my remaining aurora pictures were taken with a hand-held phone camera.
I've seen some really rather good phone camera images of this display (from a number of people how may well be reading this), and they exhibit a steadiness of hand that eludes me. Here's my best two.
The first was taken at 00:005 on the 11th (you can see the Sony camera display on the telescope busily taking images). The second was taken at quarter past one, through the bedroom window, as I was tucking up in bed.
You can click/tap to big this image.

In the second one you can make out the Pleiades at the top, and Orion at the bottom, Jupiter is the bright thing in both images.
Overall, despite not making the 360 degrees of aurora of the 10th May (see the image here), this was the most impressive northern lights I've seen with the naked eye.

Moving on....

10th October - Caldwell 43 "the Little Sombrero galaxy".

I had had plans for a while to get an image of C43 (or NGC 7814), the "Little Sombrero" galaxy in Pegasus. With clear skies predicted, and a just less than first quarter moon that was low enough the set quite early, the 10th October seemed like the ideal opportunity.
The galaxy owes it monicker to its resemblance to M104 (the Sombrero galaxy in Virgo). C43 is 'little' mainly because it is further away than M104, 40 compared to 28 million light years,
On to the images. Disappointingly, all the single frames I took seemed surprisingly red/pink, here's a typical example...

I carried on regardless, for 275 20 second frames, and ended up with this:
You can click/tap to big this image.

This is a far poorer image than I had hoped for, and I'm going to blame this entirely on interference from those pesky aurora! It should have looked a bit more like this image of M104 from April 2016.

COMET NEWS

For those looking for comet C/2023 A3 (Tsuchinshan-ATLAS), now low down in the evening sky, I can announce that this is not going to be a stunning naked eye visible comet. I had a look for this on the 11th, when I really didn't expect to see it, and indeed didn't see it. I also had go on the 12th, when I thought it may well be visible, to no avail. Looking at the observed magnitudes from the Heavens Above website, the comet has dimmed from -3.3 a few days ago (which would be spectacular in a drk sky), to 1.2 now (the 13th). It will continue to dim as it moves away from the sun. It may be naked eye visible as it moves into darker skies, but I don't think it's going to be the sort of thing you just glance around the sky and see.

That's the end of the October images (quite an interesting month I thought).

Remember, you can see the best images from previous years in earlier posts on this blog.