Xilman

11 hours ago, Paul M said:

Unless we're calling Pluto a TNO? Surely not...

(134340) Pluto is undoubtedly a TNO. The largest by diameter and second by absolute magnitude because although (136199) Eris is a few kilometers smaller it has a markedly higer albedo.

If you would like to try for objects at higher declination, you may wish to consider (136472) Makemake and (136108) Haumea. Both are coming to opposition in the next month and both are 17th magnitude.

This one is (90482) Orcus.  according to the MPC it was magnitude 19.1 and 48AU away from us at the time of observation.

Technical details: 5160s unfiltered exposure with a SX 814 Pro on a 0.4m Dilworth.  Mid exposure at 2023 Mar 15 - 00:35

Apologies for the poor tracking.  Deconvolution will remove that but will also require a round tuit which I don't presently have available.

At least one more TNO to come in the next few days, DV.

4 hours ago, bosun21 said:

This is totally subjective of course and I am not wishing to start the frac/reflector/ SCT debate.

Oh what a shame!  I just love a vehement religious war where everybody is wrong and everybody is right.  One can learn so much from other people's strongly held views.  😉

On 03/03/2023 at 11:54, Jasonb said:

Bug'r it! 

 

Buggrem all.

Never worried me.

Perhaps I am more reckless than some.

On 01/03/2023 at 16:55, doublevodka said:

Although by your locations and kit list, I suspect you do things in a much more professional capacity than me

I wish to state that I am not now and have never been ... a professional astronomer.  (With acks to Tom Lehrer.)

Everyone can do good scientific research work if they put in some well-targeted effort. Expensive equipment in an optimal location might be desirable but it is very far from being necessary. In the field of astronomy a pair of binoculars used in a suburban back garden is easily adequate. Existence proof for this assertion: George Alcock.

All you need to do is to get your ass into gear (to use an American colloquialism), record what you observe, and then publish your observations.

Are you up to the challenge?  You may get fame, fortune and glory as a result.  Well, fortune is vanishingly unlikely but fame is certainly on the cards.

6 hours ago, Mike Q said:

I shouldn't knock a 80mm refractor, they make such good finder scopes for big reflectors. 

Here is the kit inside my dome.

As you see, a Vixen R120S also makes a fine finder.  (In reality, the finder is barely visible metallic object the other side of the white scopes.  It is home-made from a discarded achromatic lens.)

The chap in the photo is the guy from whom I bought the observatory almost 5 years ago now.

44 minutes ago, CraigT82 said:

Wow how big must your step ladder be?! 

250mm of course.

7 hours ago, Bogmonster said:

What do you guys do?

Most of my kit is in here. The faint square patch in the circular wall is a vent which prevents wildlife getting into an extractor fan which runs 24/7 - primarily to keep everything inside at ambient temperature and reduce dome seeing.

An old and unused Meade is stored in a well-ventilated but unheated workshop, essentially a fancy name for a garage which cars can't get into.

Back in Cambridge, a 250cm Dobsonian is in an also unheated conservatory to be hauled out onto the lawn for use.

16 hours ago, Xilman said:

 A Canon 1000D cost me £20 on eBay, sold as "for repair or spares" because it will not take exposures shorter than 30 seconds. While crippling for terrestrial use it is ideal for astronomy. Ancient lenses don't cost much more than that either.

Just picked up a Canon EF 18-55 mm on Ebay for £11.50 + £3.95 postage. Even less than the camera. Another spares or repairs job.  The autofocus doesn't work in this case.  AF is completely useless for astronomical work anyway.

So: a wide-field imaging system for a marginal cost of less than forty quid. I already have the telescope for narrow -field work and a mount for both of them. An hour or so and a lump of scrap metal sheet should be all that's needed to complete the job.

Also have my eye on a 80-200 for a similar price.

34 minutes ago, doublevodka said:

Don't get me started on the multiple scopes route @Xilman I already want one of these... https://www.firstlightoptics.com/alt-azimuth-astronomy-mounts/sky-watcher-az-gtix-dual-saddle-alt-azimuth-astronomy-mount.html

Although by your locations and kit list, I suspect you do things in a much more professional capacity than me

Looks good to me.  I won't buy one because I have no immediate use for it.

I also have a cruddy Newtonian on a GEM which hasn't been used for over 5 years. I have been giving serious consideration to adding a DSLR to its counterweight so that wide-field photography for bright-star photometry, serendipitous discoveries such as meteors, etc  can be made while peering through the Newtonian at other things. A Canon 1000D cost me £20 on eBay, sold as "for repair or spares" because it will not take exposures shorter than 30 seconds. While crippling for terrestrial use it is ideal for astronomy. Ancient lenses don't cost much more than that either.

2 hours ago, faulksy said:

dob would be the best. but like peter drew said 80mm apo would be good. you could use that as a finder or counter weight 🤣

Don't knock the counterweight proposal.  Two scopes on the same mount have a long and productive history. Both can be used at the same time, with different filters perhaps, or  one as a guidescope , or separately where one is more suited to the target than the other.

FWIW, I have three scopes on the same mount, not counting a small and crude finder. The reflector is used for deep sky, photometry, etc. The 120mm achromat for lunar and planetary, and the 80mm apo for solar.  None of them are counterwieghts because the mount is a fork, not a GEM.

21 hours ago, Xilman said:

Can you see any of the globular clusters in M81?

They are within reach of amateur astronomers. Evidence on request..

That was not a rhetorical question and the answer is "yes"  Here is one of them in your image.

Take a look at https://britastro.org/observations/observation.php?id=20190311_020000_9a2c47fcf9f3ee97 to see if you can find any more.

Well done, in other words!

Can you see any of the globular clusters in M81?

They are within reach of amateur astronomers. Evidence on request..

5 hours ago, DaveS said:

And real astronomers haven't pushed their telescopes around for a very long time, more likely to be found sitting in warm, well lit control rooms on the top of mountains.

In my case, 760/2400 of the way up to the telescopes about 11km north of here.

Though I do have a warm, well lit control room.

Whether or not I am a "real astronomer" is left as an exercise for the reader.

On 19/02/2023 at 07:43, tezz said:

So my plan of action is to sort out the shed with very good locks and smart sensors and see if anyone try's to break in.

When I get the insurance sorted, then I will setup the scope 

I firmly believe in "as well as,  not instead of" in cases like these.

The jargon is "defence in depth".

I have no choice but to use GOTO on my main scope.

Binoculars, never GOTO.

2 minutes ago, bomberbaz said:

I have an external hard drive. Documents, pictures etc which I deem extremely important are back up to that, nothing else is saved but I do keep my eye on things and luckily have always seen failing before it's got to a critical stage.

Here's hoping you continue to be lucky.

47 minutes ago, bomberbaz said:

Ahead of you on this one vlaiv, I moved all the pictures, video and other media from the storage on the Nvme drive onto the  8TB mechanical drive last night and that leaves me a little over 600GB free. Should cover my needs I think.

Do you take backups of that drive?

Serious question.
My files are backed up to a separate machine (a rather elderly Linux box) fitted with a ZFS 3-disk array.  Three 2TB drives give 3.6TB usable storage.  One drive hard-failed a while back and was replaced with a 4TB unit (it cost about the same as a 2TB disk) but the RAID array sailed through the episode.  The other two disks are showing faint signs of age but neither have failed yet:

pcl@ra:~$ zpool status
  pool: backup
 state: ONLINE
status: One or more devices has experienced an unrecoverable error.  An
    attempt was made to correct the error.  Applications are unaffected.
action: Determine if the device needs to be replaced, and clear the errors
    using 'zpool clear' or replace the device with 'zpool replace'.
   see: http://zfsonlinux.org/msg/ZFS-8000-9P
  scan: scrub repaired 0B in 0 days 13:27:01 with 0 errors on Sun Feb 12 13:51:03 2023
config:

    NAME                        STATE     READ WRITE CKSUM
    backup                      ONLINE       0     0     0
      raidz1-0                  ONLINE       0     0     0
        wwn-0x50014ee2bf658d03  ONLINE       0     0     0
        wwn-0x5000c500c0fc45a7  ONLINE       0     0     3
        wwn-0x5000c500c0d65bf2  ONLINE       0     0     2

errors: No known data errors
pcl@ra:~$ df -h /var/lib/backuppc
Filesystem      Size  Used Avail Use% Mounted on
backup          3.6T  1.2T  2.4T  33% /var/lib/backuppc

I will replace them when I return to Cambridge.

My experience is that SATA SSD are markedly faster than SATA HDD. This holds even when each drive is plugged into identically the same cable and SATA port.

One big difference is latency. If the sector you want to read or write is on the opposite side of the platter from the R/W head, you have to wait for half a rotation period (over 100 microseconds) for anything to happen to a HDD. Latency is hundreds of times smaller on a SSD.

Over the decades a great deal of effort has gone into hiding this latency by intelligent reordering of sector layout and disk operations, caching (originally just in system RAM but now also on-HDD) but it can not be eliminated entirely.

On 18/02/2023 at 22:17, Xilman said:

 Might give it a try now that I know of its existence but don't expect to have much success ...

Here is a teaser.  Rather more later, I hope, when I have finished collecting data and processed the results properly.

On the left is my crude attempt.  On the right is the DSS2 image as displayed by Aladin Lite. Note my camera is rotated by about 12 degrees.

This is the magnificently named (229762) Gǃkúnǁʼhòmdímà.  It is a Scattered-Disk Object, meaning it orbits the sun in an eccentric (e=0.4843) and highly inclined (i=23.378 degrees) orbit.At the time of observations (2023-02-23) it was 40.95 AU from the earth and magnitude 19.8.  The image shows a very small trail of the SDO, which may be compared with the circular appearance of stars of similar brightness.

Technical details: 0.4m Dilworth, unfiltered SX814 CCD camera. 2790s exposure in 93 subs of 30s each.

(No I can't pronounce the name, despite having heard it spoken.  It will always be (229762) to me.)

12 hours ago, Paul M said:

Fascinating subject Paul, we've discussed it a few times in the past and I just happened to to look at some of your other images of far-flung Solar System objects on your web pages a couple of days ago.

I hope to capture a few before spring gives way to summer.

If you check the BAA Handbook you will find a few close to or somewhat past opposition (so visible in the evening sky) and at a fairly northern declination.Over a year there appear to be 12 which reach mag 20.0 or brighter, which should be within range of a single night's observation with a 20cm or larger. This estimate is based on the facts that my 40cm has four times the collecting area and took 85 minutes to reach mag 20.3 with ease.

Good luck with your project and please display your achievements here.

Two possibilities immediately come to mind.

One is to rename "Planetary" to "Solar System Bodies Other Than Sun or Moon" which encompasses the topic very nicely but may seem a little long-winded. There may be better phrasing.

The other is to create "Small Solar System Bodies" and leave it to the good sense (if any!) of the posters.

I favour the latter.

Paul