lukebl

Hi folks,

Here's a capture of the International Space Station as it flew over this evening from about 17:30 to 17:32.

Captured with a Canon 6d, Omegon RC8 (1600mm f/8), 1/800 second exposures, ISO800. I hand-tracked the scope through the finder as the station passed over, and fired the shutter continuously and selected the best frames.

At its closest it was about 528 kilometres from me. I love the way the orientation changes as it goes over.

Here's an animation of 16 frames:

Here's a single frame. Shows how tiny it was!

There's a launch of another 60 of them today at 1449UT.

It's scary that it's so unregulated, and that anyone can put any old junk up there and bombard us with whatever commercial rubbish they wish. Especially when other organisations are looking at ways of cleaning up old space hardware up there. It's wanton greed and pollution, pure and simple.

Nice captures. I have one of those Venus UV filters which I'm looking forward to trying out over the next few months.

BTW, although Venus rotates once every 243 days, the clouds circle the planet every 4 days so you can see changes over a relatively short period.

I captured this interesting asteroid over the weekend. It's an earth-crossing Apollo asteroid on a close approach at the moment, and consequently moving by rather fast. It's currently at a distance of less than 0.1AU and won't be this close or bright again for a few decades. It spends most of its time below 21st magnitude, but it's currently around magnitude 15 and when I captured these images is was moving at a rate of 11.50"/minute. I understand that its diameter is several hundred metres.

I captured a number of 30 second exposures, with my 200mm f/5 Newtonian + 0.9x coma corrector and Atik 428ex, binned 2x. The field of view is 33.5 x 25.2 arc mins.

This shows the position of the asteroid at approximately 5 minute intervals. Even with 30-second exposures the movement was noticeable.

This shows a series of 29 consecutive images, stacked on the asteroid using Astrometrica.

This is an animation of an enlarged part of the above image.

And this is a 3d image of the orbit of the asteroid. As you see, it comes alarmingly close!

Running the frames through Astrometrica revealed a few other asteroids in the frame. Most were too faint for me to capture, but this one, Asteroid (37291) 2001 AP26, was at magnitude 19 and just visible in this aligned stack of 100 frames. Unlike 437316, it's in the main outer asteroid belt and approximately 10.5 km across. The streak across the middle is the path of 437316.

Here's a capture this evening of the Eskimo planetary nebula in Gemini (NGC 2392, Caldwell 39).

It's easy to see and find, being bright at magnitude 10, but rather small and difficult to capture the very odd fine details. It's also in a very sparse star field, so there's not much else to see here!

Omegon RC8 (1600mm FL), Atik 428ex, 15 x 180s exposures each of Ha and Oiii. Synthetic green. Field of view: 14 x 18.6 arc mins.

Small point of interest. You can make out the Crab pulsar in my image.

One of very few pulsars to be visible optically. It's just 20 kilometres in diameter (20 kilometres!) and rotates 30 times a second.

Here's a slightly less 'cooked' version, which I feel is more pleasing.

Every year I'm drawn to the Crab Nebula, in the vain hope that I might be able to improve on my previous images. This is my latest attempt, using an Omegon RC8 and Atik 428ex. I foolishly thought that getting a longer focal length would mean bigger image on the sensor and thus more detail (my previous captures used a 250mm f/4.8 Newt).

Of course, I'd failed to take into account pixel scale, seeing and the vagaries of the NEQ6 mount. The current combo unbinned gives a pixel scale of about 0.5"/pixel which is way oversampled. And the mount is hardly high-precision. The result is that unbinned images are no sharper than those binned at 2x. Of course, though, binning has the benefit of greater sensitivity.

In fact, this image shows less detail than my previous efforts with the Newtonian. It's still a magical object, though.

Anyway here it is. 20 x 300s exposures each of O-iii and Ha. Green channel synthesised with Noel's Actions in PS.

I couldn't help noticing that a few asteroids named after actors, characters or producers from the original Star Trek series are well placed in the evening sky at the moment. So I thought I'd try and capture them this week. The presence of high clouds and the nearby moon means that these are hardly pretty images, although at least they show the target in question! These were all captured with my Atik 428ex and 200mm f/5 Newtonian. The positions were all verified by Astrometrica.

First up is 7307 Takei, named after the wonderful George Takei, AKA Mr. Sulu. Still alive and kicking. This one is relatively bright at magnitude 16.8, and currently very near the Pleidaes. This is a stack of 5 x 120 second exposures.

Here's an animation of the first and last images, showing the slight movement over the period of about 10 minutes.

Next one is 68410 Nichols, named after the equally wonderful Nichelle Nichols, AKA Lt. Uhura. Also still with us. This one is very dim at mag 19.3 and only just visible in this stack of 27 x 60 second exposures binned 2x. Currently quite near Takei in Aries.

This one is 2309 Mr. Spock, a 16.3 magnitude asteroid in Cetus. 20 x 60 second exposures. The story goes that the asteroid was named after the discoverer's cat, Mr. Spock. But since the cat was named after the original Mr. Spock, then I will assume that the asteroid was too! I did try and capture 4864 Nimoy, named after Leonard Nimoy AKA Mr. Spock and currently in Aquarius, but it was close to the moon and at 18th mag. was washed out.

This one is 4659 Roddenberry, named after the creator of it all Gene Roddenberry. Magnitude 18 in Pisces. 20 x 60 second exposures binned 2x, and stacked on the asteroid hence the star trails. There is also an asteroid Shatner, currently in Gemini. Sadly, none of the other original stars have asteroids named after them. There's also one named Tenagra after a place in one of my favourite Next Generation episodes: 'Darmok'.

OK. That's enough nerdy stuff for the time being.

The return of Doctor Who reminded me that I really must fix the leaky roof on my Tardis Observatory.

Here I am painting gloopy bitumen paint all over it today. The roof really needs a redesign to direct the rain outwards as it's getting alarmingly damp inside.

On 13/11/2019 at 14:16, don4l said:

Has anyone ever even photographed a geostationary satellite?

 

I know this is a response to an oldish post, but it's an important one.

Definitely YES, geostationary satellites can be imaged, and frequently, although stacking software can usually remove the trailing. And just because they are geostationary doesn't mean that they don't move against the backdrop of the night sky. They still create trails on images.

Most of them orbit in a line above the earth's equator, and thus from the UK are seen a few degrees below the celestial equator due to parallax. This means that they frequently photobomb images in that area, such as the Horsehead and the Orion Nebula. Admittedly, they are fairly faint, and nothing on the scale of Starlink which will occupy every part of the sky from North Pole to South Pole.

58 minutes ago, Peter Drew said:

It would have been pre laser collimation.    😀

Is that good or bad?

Interesting but surely, with four mirrors to deal with, collimation would be an absolute nightmare?

Coming out of the departure terminal at Luton Airport this evening, I was greeted by this beautiful and rather surreal view of the Moon, Venus and a control tower.

Much to the annoyance of my companions, who were desperate to get home after a long journey, I had to stop and capture the view. Unfortunately my tripod was packed away, but I managed this one shot which didn't have too much camera shake. Canon 700d, Canon 75-300mm @ 105mm, f/11, 1/2 sec. ISO 800

I'm on holiday in Sicily and also logged on. Here's a pic of my two sons and me on Mount Etna today. Christmas Day!

Glad to be sad!

Lovely view of Saturn and Venus after sunset this evening. Banham, Norfolk

Canon 6d. Canon 70-300mm lens @ 120mm f/6.3. 3.5 seconds. ISO800

Here's an oldie from my earliest efforts at imaging from 3rd May 2009. Probably captured with a Phillips webcam, 3x barlow and 200mm f/5 Newtonian.

I was up at 4 am to view the shower. There were a few clear gaps, which increased towards dawn.

But meteors? Zero. Zilch. Zit. Nada. 

I should have expected that, really!

10 hours ago, Star101 said:

It was bright. So I put the Ha filter to dim it a little.

 

Very nice. Apart from dimming it, are there any other benefits to imaging the moon with Ha?

Another little animation of the clouds.

Shame about the Newton's Rings

I was hoping to catch a series of images at the early stages for an animation, but the clouds were a problem.

However, they did make for quite a pretty animation here. This is between First and Second Contact. You can see Mercury as a little notch at the 1 O'Clock position.

1 hour ago, johninderby said:

Telescope Express does a tilt adjuster to fit.

https://www.teleskop-express.de/shop/product_info.php/info/p4272_TS-Optics-M90-Tilting-Adapter-Flange-for-astrophotography.html

I've fitted one of those. It all seems aligned according to the Cheshire.

58 minutes ago, Ben the Ignorant said:

A star test is good only when the optics are placed well relative to each other. If there's a misalignment somewhere, it's not in the optics.

Note sure I really understand what you're saying here.

What I'm querying is what should I read into the conflicting results of the Cheshire collimation vs. the star test, and what I need to do to achieve optimum collimation if I can't trust either method?

Perhaps someone can help me here.

Despite the horror stories about RC Collimation on the web, I have a 203mm f/8 Ritchey-Chretien.

Being a tinkerer, I do like to get things like collimation as close as possible to perfection. Something has been puzzling me about this scope: If I put the Cheshire eyepiece in the focuser, I can adjust the secondary in the traditional way to get the centre circle dead centre. All well and good. I haven't dared fiddle with the Primary mirror yet.

However, If I then do a star test I get the results shown below (excusing the effects of turbulence and heat currents). The left-hand pair of images shows the out-of-focus star after 'perfect' collimation with the Cheshire. Collimation is clearly off. So I then adjust the secondary till I get the images on the right which suggests that collimation is better with stars nearer a circular shape.

However, if I then check with the Cheshire, I get the view shown below. The centre circle has moved off-centre suggesting collimation is out, even though the star test suggests that I've improved it.

So, do I ignore what the Cheshire is telling me and assume that the star test is more accurate? The word on the street is that you need a Howie Glatter collimator with circular laser attachment, but these aren't made any more so that's hopless advice!

Hi folks. I imaged this interesting pair of colliding galaxies last night, NGC 520. Apparently called the Flying Ghost Galaxy and discovered by William Herschel. To its upper right is PGC5195, a 16th magnitude spiral galaxy.

Aside from the issues I'm having with collimating my RC (A newt is a doddle compared to this), my guiding has been a bit iffy so I thought I would try it with a lot of short exposures. This is the result of 170 x 2 minute exposures, plus 15 x 1 minute binned 2x for RGB. Rather disappointed at the lack of detail. But it's quite diffuse and would clearly benefit from some more and longer exposures. 203 mm f/8 Ritchey-Chretien, Atik428ex. Field of view: 18.6 x 14 Arcmin, Pixel scale 0.578 arcsec/pixel.

I noticed on the lower-left of the subs a moving star, which turns out to be 16th magnitude asteroid 3117 Niepce discovered in 1983 and named after Joseph Nicéphore Niépce, credited with taking the first ever photograph. Here's an animation of it. Each frame was 20 minutes apart.

A quick run through Astometrica revealed a couple of other fainter asteroids, numbers 20905 and 345190, of which I know little apart from the fact that the former was discovered in 1960 and the latter in 2005. This is a no-frills stack using 'Track and Stack' in Astrometrica showing the three. Interestingly, they are all moving at approximately the same rate and direction. Often when I've captured multiple asteroids, they move in very different speeds and directions to each other.