My First Asteroid - 3rd Light for the SV140 - Sat 18th Mar 2023

[Captain Scarlet]

After weeks of drizzle and fog, not surprising at my heady altitude of 93 metres (air’s pretty thin too) Saturday night was suddenly forecast clear. The Moon well out of the way too, so ordinarily I would’ve set up my 12” newt to take maximum advantage of the dark. But I’ve been itching to get some more use from my latest toy, my SV 140 refractor. I went for maximum convenience, setting up on the patio right outside my door with a Northerly view but spanning 180 degrees left and right over the creeks and Islands.

 

I also cobbled together a quick list. As mentioned, I had my new Stellarvue SVX140 on an AZ-EQ6/Planet. The night ended up measuring 21.7 on my SQM-L. Seeing seemed OK, transparency good to start, but deteriorated later on. I aligned using a DeLite 18.2 (52x) and settled for most of the session on my Delos 6 for 156x, occasionally rising to my DeLite 3 for 313x. Towards the end I used my gorgeous Nagler 31T6 for 30x.

A week or so ago, I drove to Cork (90 minute drive) to listen to one of Cork Astro Club's members give a talk about Sundials, his speciality, and I hadn’t realized it also doubled up as the Cork Astro Club’s monthly meeting. So I also sat through another talk, given by their observer-in-chief, about what was going on in the night sky this season. I learned that 1 Ceres, the brightest (by far: Ceres is mag 6.9, the next is in the teens!) asteroid/dwarf planet in our Solar System, was near opposition and eminently observable. Thus my first objective was 1 Ceres, which I’d never heard of before let alone observed.

I now know that 1 Ceres is an asteroid, but last night I knew it only as a dwarf planet, and none of the 60-odd catalogues available to me in the Nexus DSC seemed to fit the bill. It does have a couple of asteroid catalogues but like I said… . So I resorted to a fancy new modern technique that I’ve recently heard about called “star hopping”. Looking it up in SkySafari I found my way from Denebola to Messier 88, hopped up a couple of viewfinder-widths North and West a bit (IIRC) and matched the star-fields: Bingo! Mag 6.9 so it was the brightest thing in the immediate vicinity, but no disc discernable. I’ll have to do the calcs to see if a disc was too much to expect. Maybe someone can chime in to the flood of comments after this 😊.

I wanted to see Herschel’s Garnet Star, aka Mu Cephei, and remind myself just how red it is. I found it easily enough, and yes I could see it was a bit orange-ish but that was it. Perhaps I should have treated it like a planet and looked at a bright white screen to activate my cones to get the colour better, I might try that next time.

Next was another red star I rather like, the central star in M37. Again, underwhelming, the same could be said for the whole cluster, actually. It turned out there was a reason for both this and Mu Cephei being a bit dim.

I could see Vega and Lyra were now possibly far enough up to be worthwhile, so I went for Eps Lyrae (The Double Double) at 156x, to be greeted by two pairs of tiny but perfectly separated dots, and no discernable diffraction rings. One of my favourite targets, I stayed for a while here. Whilst still in the region, I quickly and casually star-tested on Vega: perfection as far as I could tell.

I had M35 on my list, not sure why, it was nice enough if I recall. At this point I changed to the Nagler 31 to give me my widest field of 2.7 degrees and 30x magnification. M35 suddenly looked much more compact! I love the wide fields a medium refractor gives you.

At this point I decided to finish off with NGC 1502 and Kemble’s Cascade, to see if I could identify any star colours in Kemble’s Cascade – it’s supposed to be famous for those colours. NGC 1502 is a small OC at one end of the asterism, and it was dim and slightly underwhelming. I “got” the Cascade, but not impressive and certainly no colours. Hm. I looked up and suddenly the mystery was solved. I could, naked eye, barely see even the Cassiopeia “W”. That northern aspect was veiled with cloud, explaining as well my earlier view of Mu Cephei. So that was it, time to pack up.

I’m still very much enjoying this scope, and it was good to get anything out even for a short session after all the solid cloud we’ve had recently. I was especially pleased to see 1 Ceres.

Thanks for reading, Magnus.

Edited March 20, 2023 by Captain Scarlet

[John]

Nice report Magnus, great looking scope in a wonderful location too 🙂

On the apparent diameter of 1 Ceres, Stellarium gives a figure of .83 arc seconds which is co-incidentally similar to the apparent diameter of Jupiter's moon Io.

With the Galilean moons I have found that it is possible to notice differences in what appears to be their apparent diameters with scopes of 100mm or more aperture and from this I have been able to work out which was which on a particular night without looking up their relative positions.

The challenge with 1 Ceres is that there are no nearby objects in the sky with which to directly compare it's apparent diameter with, in the same field of view, so it may well be rather difficult to work out if what you are seeing is it's true disk or something more akin to an airy disk as you get with stars. Maybe that is also the case with the Galilean moons but there are definitely visual differences in apparent size between them whether though varying airy or true disk diameters.

I guess that does not really answer your question - I would be very interested to hear what others think 🙂

Thanks for posting your report and that lovely photo 👍

Edited March 20, 2023 by John

[jetstream]

1 hour ago, Captain Scarlet said:

It turned out there was a reason for both this and Mu Cephei being a bit dim.

Congrats for a fine session!

Excellent seeing Ceres ,that is a real catch, nice one. Yes its very hard to get the colours out of stars with any kind of light high cloud, or worse. After a perfect clear sky day, it has now clouded over, so off to the the seacan to put the 15" back and then into the hot tub lol.

That scope sure looks great Magnus as well as your mount and tripod - and the location!! Everything looks perfect where you are and I'm sure more clear skies are coming soon.

Gerry

Edited March 20, 2023 by jetstream

[Stu]

Very nice report Magnus, glad to hear the scope is working well.

Kemble’s Cascade is a lovely one when skies are good. Not sure if you saw this thread from Ed? The little double in NGC1502 is nice to pick out.

Regarding asteroids, SkySafari has a list of them, and there are three more which are brighter than mag ten; Pallas, Vesta and Juno. Plenty more at mag 10.x and 11 too. Think I’ve seen Vesta, Ceres and Juno, can’t recall seeing Pallas.

[Nik271]

Very nice report and a good looking scope, enjoyed reading this!

Ceres will pass the 6.8 magnitude HD 108239 next week heading directly to M100. It may be possible to compare its disc with this star. At 0.8'' the big aperture may show difference in size.

[Captain Scarlet]

21 hours ago, John said:

Nice report Magnus, great looking scope in a wonderful location too 🙂

On the apparent diameter of 1 Ceres, Stellarium gives a figure of .83 arc seconds which is co-incidentally similar to the apparent diameter of Jupiter's moon Io.

With the Galilean moons I have found that it is possible to notice differences in what appears to be their apparent diameters with scopes of 100mm or more aperture and from this I have been able to work out which was which on a particular night without looking up their relative positions.

The challenge with 1 Ceres is that there are no nearby objects in the sky with which to directly compare it's apparent diameter with, in the same field of view, so it may well be rather difficult to work out if what you are seeing is it's true disk or something more akin to an airy disk as you get with stars. Maybe that is also the case with the Galilean moons but there are definitely visual differences in apparent size between them whether though varying airy or true disk diameters.

I guess that does not really answer your question - I would be very interested to hear what others think 🙂

Thanks for posting your report and that lovely photo 👍

I can easily see Uranus as a disc, it's 3.5 arcsecs. I can just about detect that Neptune is a disc, at slightly over 2arcsecs, but that may be difficult because it's also so dim. But I reckon Ceres at <1" might be beyond my disc-detectability. I'll try with my 12inch at high mag the next time I try, and see what I see.

[John]

7 minutes ago, Captain Scarlet said:

I can easily see Uranus as a disc, it's 3.5 arcsecs. I can just about detect that Neptune is a disc, at slightly over 2arcsecs, but that may be difficult because it's also so dim. But I reckon Ceres at <1" might be beyond my disc-detectability. I'll try with my 12inch at high mag the next time I try, and see what I see.

I've found Uranus and Neptune respond well to high magnifications, sometimes very high magnifications (ie: 400x or more). With my 130 triplet I've spotted Neptune's largest moon Triton at such high magnifications. Your 140mm should be able to spot that and maybe even a couple of Uranus's moons on a dark night 🙂

[JeremyS]

Great report Magnus. Felt I was there with you 👍🏻.

As John says, I find Uranus and Neptune do take v high mags well

[Epick Crom]

Fantastic report Magnus from your picturesque location and congratulations on seeing Ceres for the first time 👍

Wishing you clear skies

Joe 

[JeremyS]

Hello  Magnus @Captain Scarlet. Coincidentally in the last 24h someone has  discussed resolving Ceres on CN

https://www.cloudynights.com/topic/869026-ceres-possible-resolution/?hl=%2Bmewlon+%2B210#entry12582322

Edited March 23, 2023 by JeremyS

[Paul M]

Wow! The very idea of someone resolving Ceres has apparently passed me by. Not that I've given it that much thought, but when Magnus mentioned it above I just thought, "nah!"

So, another crazy challenge to add to my "to do" list, if ever there is a clear sky again! 

 

[Captain Scarlet]

2 hours ago, JeremyS said:

Hello  Agnes @Captain Scarlet. Coincidentally in the last 24h someone has  discussed resolving Ceres on CN

https://www.cloudynights.com/topic/869026-ceres-possible-resolution/?hl=%2Bmewlon+%2B210#entry12582322

The message I get from that thread about being able to resolve it is “highly unlikely”. Certainly not in my 140, and the combination of factors that need to come together to make it possible in my 12” are too much I think. I’ll try though given a chance.

[vlaiv]

15 minutes ago, Captain Scarlet said:

The message I get from that thread about being able to resolve it is “highly unlikely”. Certainly not in my 140, and the combination of factors that need to come together to make it possible in my 12” are too much I think. I’ll try though given a chance.

You can practice on Galilean moons first?

They are 1.8" down to 1" when Jupiter is closest to us and smallest apparent diameter of Europa when Jupiter is the furthest (0.665")  is about the size of Ceres when it is close (it ranges from 0.34" to 0.854")

[Captain Scarlet]

17 minutes ago, vlaiv said:

You can practice on Galilean moons first?

They are 1.8" down to 1" when Jupiter is closest to us and smallest apparent diameter of Europa when Jupiter is the furthest (0.665")  is about the size of Ceres when it is close (it ranges from 0.34" to 0.854")

I could but I'll have to wait nearly a year before I get the chance, I fear

 

Edited March 23, 2023 by Captain Scarlet