Mandy D

SpaceX CRS-25 went over at 22:47 on a supply mission to ISS. Not as bright as ISS but still unmissable. It is back again10 deg above WSW at 12:17 Saturday morning.

38 minutes ago, robin_astro said:

Now there's an interesting challenge, to observe an occultation of a star by the ISS. I wonder how narrow the path would be ?  I did catch a Jupiter transit quite a while back though when the data to be able to predict  this sort of thing were not so widely available (and the ISS was quite a bit smaller)

http://www.threehillsobservatory.co.uk/astro/astro2_image_67.htm

Cheers

Robin

Your capture is impressive. This near-occultation of Altair was seen from Northampton and North Derbyshire. Given how close the ISS is to us, I think the path would be quite narrow.

49 minutes ago, Laurieast said:

Using Stellarium it was Altair.

Yes, definitely Altair - Beta Aquilae was to the west of it. Thanks for confirming this. I spent ages on Stellarium trying to get the ISS in my sky at that time, but my location was bizarrely in the Middle East! Very dodgy. It is now back where it belongs, somewhere on the edge of the Derbyshire Peak District, between Derby and Sheffield, so not a huge distance from you. Great to know we could both see the same thing.

Just watched the 23:07 passage of the ISS from North Derbyshire. It grazed a bright star in my SSE and near max elevation. Rather cool to see.

On 04/07/2022 at 19:43, TheycallmeRiver said:

I want to take a series of 3 or 4 moon phase photos, process them, and then put each on a separate canvas and stick them up on my living room wall.  I'd like them to be as high a resolution as is feasible, because i'm going to be blowing them up to quite a large size.

I have an entry level DSLR thats a few years old, a Nikon D3300 and I assume it would be usable for this project if I bought a T Ring?   Would that be good enough for this purpose, and maybe for some planetary shots later this year when the time is right; or should I prioritise a lower end planetary camera instead?

 

I've used a D3200, which has the same sensor as the D3300, for lunar imaging and get respectable results. The attached image was acquired with a 600 mm focal length. It's not the best that the camera can achieve and was at ISO-400, so there is plenty of scope for improvement. My iOptron RC6 has a focal length of 1370 mm and I can fit the entire full Moon on the crop sensor. I think you should get good results with your camera.

My newly acquired Skywatcher 200P photographing the Supermoon last night.

On 20/06/2022 at 21:09, robin_astro said:

Reminded me of a project "Light Beam Communicator" in "Electronic Novelties for the Constructor" by EM Bradley (which predates the invention of the laser), one of the first books on electronics I had as a lad in the early 1960's

 

 

Boys, huh? Because girls really would not have been interested in talking to each other back then and, of course, electronics would not have been a suitable interest either! Thankfully things have changed. V1 and V2 are some strange looking transistors!

Last night's Supermoon was my first chance to try out my newly acquired Skywatcher 200P. Unfortunately, the collimation was so far off, the telescope could not even bring an image into it's field of view, so I spent yesterday afternoon learning how to properly collimate a reflector! Thankfully, a cheshire was included with it! I only got 18 minutes for imaging, but the telescope proved itself quite nicely, although I'm sure focussing could be a touch better. The D800 made the telescope a bit front heavy, but the mount handled it well after tightening it. All photography was at a site near Chatsworth House in the Derbyshire Peak District. As we were leaving, I spotted Jupiter and Saturn rising, but with everything packed up they will have to wait for another night. Now, if only I can get similarly sharp images from my iOptron RC6!

Antares and our Moon were hanging out together in the sky last night. This image captured at 21:19 UTC shows Antares (bottom left) as a deep red colour, whilst the Moon is somewhat over-exposed. The photo was taken at the side of a main road as the Moon, low in the sky, was obscured by trees in my garden. I certainly managed to slow down the traffic as I was near traffic lights with a 300 mm lens on my camera and I'm sure some thought it was a speed or traffic light camera!

The two fitted nicely on the crop sensor of my D3200 with the 300 mm lens.

D3200, f/8, 1/100s, ISO-400, 300mm.

Processing in GIMP - crop and sharpen.

@knobby, thank you. PMd a reply.

Very beautiful image. I think the orientation of the first photograph is superior, artistically. Perhaps, just add a note to it to indicate the "improper" orientation. That you captured this in Wales is an added bonus!

There is no up and down in space!

Beautiful collection of sunspots.

Under the foliage of an ancient horse-chestnut tree multiple pinhole camera images of the Sun decorated the tarmac pavement this morning. A fine example of nature co-operating to give us something of beauty and scientific relevance.

Thank you, @Laurieast!

Stunning detail on your photos! I'm still practising with my imaging.

I suffered a ruptured eyeball a few weeks ago and last night was my first night out observing. I really wanted to test my RC6, but was struggling to find focus as it was my observing eye that got damaged and I'm still pretty much blind in it. Fortunately, the 300 mm f/4 Nikon lens auto-focusses very well on the Moon and coupled with a x2 teleconverter produces a nice large image on the D3200 sensor. If the skies stay clear I will probably give the RC another shot tonight.

Excellent imaging! Just need to share it with the Flat Earth Society, now!

6 hours ago, Cosmic Geoff said:

If you think the lead is holding the weights in place, then applying sufficient heat from a gas burner etc will melt it and free the weights.

In commercial mounts, the weights have a clearance hole and are held in place by a side screw with hand knob, backed up by a safety cap on the end of the rod.  If you can get these weights off, you could replace them with commercial weights - at a cost. Otherwise you will have to drill & tap a long side hole.  Or fix a common circlip on the shaft below the weights.

I don't think it is the lead holding the weights in place. It looks like they are rusted to the shaft and there is a single screw(?) in the side of the weights that is refusing to play. I may drill it out, yet! Heat, I think is likely to be deployed before too much longer.

Thanks for the info on commercial weights. I've looked at the price(!) and can certainly deal with drilling and tapping and finding a handwheel screw to work with the exisiting ones. I like the idea of a circlip on the end of the shaft to save my toes from possible injury!

@Carbon Brush You've nailed it: I'm a complete beginner with the EQ mounts, but do have mechanical experience! Sorry for the confusion.

The lead took me by surprise, too. I've felt for concealed holes for screws under the tape, but nothing. I think I'll end up drilling the screw out. I may need to get someone to heat the weights to get them off if the penetrating oil does not work, but I'll try twisting them off in a vice first.

I'm definitely planning on having easily adjustable counterweights. I've machined the small one up and bored for 3/4" to match the shaft. I have yet to drill and tap it for a grub screw.

Photo of first attempt at machining a counterweight. What size screw do you think? I'm tempted to go with M8.

@Carbon Brush I've just taken the first weight off by cutting the welds. The shaft does not go right through the other weights and the space is filled with lead! I've had another go at the grub screw, but no joy. There are definitely no threads at the top of the hole, so maybe that is clearance? I've tried metric and imperial hex keys and a flat screwdriver, but nothing. I'm reluctant to drill it, but that may be all that is left. Photos of progress are attached.

@Carbon Brush Thanks. You are correct about the welds, but I think I'll just run a slitting disc on a small angle grinder through the welds. Hacksaw is too much like hard work for my taste! I'm not bothered about a bit of damage to the weights, as I'll pop them in the lathe and put a bevel on them all, anyway, to tidy them up. The biggest problem at the moment is getting them off the shaft, as I'm not sure what is securing them. There appear to be no discernable threads in the hole and nothing I can get a hexagon key into. Bizarre!

I don't really want to make a huge project out of this, but would like to have it working. Next week is not the aim, but perhaps the week after?

A manual mount sounds OK to me. I'm used to pushing the big Dob around, anyway and an HEQ5 is planned for.

On 13/05/2022 at 09:58, Cosmic Geoff said:

Looking at the photos, it appears that any RA drive is entirely missing, while the gear (?) on the other axis is for a declination drive.  It looks like a significant amount of work would be needed to provide hand slow-motions or motorized drives.

Judging by the number of counterweights, assuming they are all solid steel, the scope originally fitted must have been unusually heavy. My 8" Newtonian required two 5Kg counterweights IIRC.

The counterweight is in three pieces all welded together for some reason. It measures 114 dia x 200, so weighs in the order of 15 kg! The appearance of lots of small weights is given by self-adhesive foil tape stuck around the big chunks of steel!

Given that the RA drive is missing, am I wasting my time on this?

Looks like it is 24 hours study, not a 24 week course, but still interesting. Thank you.

Now, if we could just get the new LED streetlights in my home town turned off, please ...

Too many lights, surely? 😇