An hour with the Tento 8x40s

[johnfosteruk]

I picked the Tento up for a song the other week and I've just had my first proper (ish) handheld session (wearing spectacles which is very comfortable with these) with them, on mainly clusters and a few doubles and I'm happy. Ish because there were occasional interruptions from clouds and the neighbours heating vent spewing out steam (grrrrr). The seeing when this wasn't the case was 3.5-4/5

The Pleiades were lovely, the main group of stars were really pin sharp, and a good peppering of other stars. I think they give me a gain of approx 3.5 magnitudes based on the fainter stars I could identify with skysafari. And reasonable contrast too given the local light pollution.

The Hyades were a real wow this evening, The field full of sparkling diamonds, Aldebaran deep orange, small chains and asterisms everywhere and a number of fainter stars within the V. Theta Tau is a great wide double  and just at the Eastern edge of the cluster near Aldeberan, Sigma is another nice easy wide visual double for the binoculars.

Moving east Cr65 was a nice challenge, being much less densely populated but nonetheless, after prolonged viewing, perhaps 35 stars clearly on show, a pretty and quite large cluster. I've read in a few observing reports of a little kite shaped asterism in the south of the cluster made up of 5 stars, saw the stars but they don't look like a kit to me!

South to Cr69, Orion's head, A north-south chain including Meissa but not much else here to excite and it's not easy to determine where the cluster ends and the surrounding field begins.

Next, a look at Betelgeuse and Rigel, panning backwards and forwards between the two, enjoying the contrasting colours. Inevitably in between them the eyes are drawn towards those winter favourites Orion's belt & M45. Alnitak, Alnilam & Mintaka are so very bright yet pin sharp. M42 appears as a faint smudge around 2 sharp points. Almost like 2 out of focus stars but with in focus stars in the centre. In this FOV the whole of Orion's sword is very pretty, the north-south chain containing NGC 1981,1975,M45 & Nair al Saif and an east-west chain just south of Nair al Saif, like an upside down upper case T. Pan up a little and it's a right way up T with the belt stars. 

The whole region appears as a very geometric open cluster but with regions of background brightness hinting at the unresolved nebulosity.

A hop south east to Sirius, scintillating madly, and M41 to its south, bright but small. I've been meaning to tick this one off the Messier list for a while and I'm going to mount the 10x50s and have a look again soon to resolve some more detail. Then it's around to Andromeda and beyond. M31 the usual huge smudge, but did I see a brightening at the core? It was in the darkest area of sky where I am tonight, happy with that.

There were a number of other targets on the list but the cloud which had only been patchy up until now and the heating exhaust were getting pesky so apart from a hazy view of Mel 20 and the double cluster (a pair of unresolved smudges through the hazy fast moving cloud) that was the evening wrapped up. Nothing too exotic but a great 'benchmarking' session for the new binos.

It's a given that these bins are coming to the dark site with me.

Clear skies

JF

 

[alan potts]

Nice report I imagine you could get down to the 9 magnitude with 40mm from a dark site maybe even a bit more. I had a look last night with my 70mm bins as the snow is still too bad to get a scope out, it was also very wet/cold last night very soon after sundown. I never normally worry too much about cold but this was sort of English cold weather, the type that chills to the bone.

Alanl

[michael.h.f.wilkinson]

Lovely report. These smaller bins are just great for really wide-field objects such as the Hyades. They really put the objects in context

[johnfosteruk]

4 hours ago, alan potts said:

Nice report I imagine you could get down to the 9 magnitude

I'm thinking you're right Alan. I didn't measure it with the app but I  estimate NELM was somewhere around 5 so the 40mm gave me something near 8. So 9 somewhere dark seems reasonable which makes them a great grab and go as far as I'm concerned. 

[johnfosteruk]

2 hours ago, michael.h.f.wilkinson said:

Lovely report. These smaller bins are just great for really wide-field objects such as the Hyades. They really put the objects in context

They do that Michael, the region around M42 comes to life as well and Cas is a beauty too. I'd have bagged M81 (and m82 with AV) if the cloud hadn't scuppered rhe session. ☁️ ⛈ ☔️