Observation report 26/03/20

[Dave1]

Hello Everyone,

So for the first time in a long time I managed to get out under the stars. I set up my Skylight 60mm F16.7. My main target was Venus. Which during dusk there was still cloud around. The image sometimes shifting due to turbulence due to poor seeing conditions. On average I say seeing was a Pickering 8 and briefly going to a Pickering 7. But as the evening went on the seeing stabilised, especially around 8 pm.

This was the first light for my Edmund Optic RKE 8 mm eyepiece, which I did a comparison against my Brandon 8 mm eyepiece. 8 mm eyepieces are just over the theoretical limits of what a 60mm telescope should be able to handle. The seeing supported this magnification. Other eyepieces used were 9 mm, 10 mm, 12 mm, 15 mm, 32 mm.

Which with my 60mm F16.7 resulted in magnifications of 32 mm = 31x

                                                                                                       15 mm = 67x

                                                                                                      12 mm = 84x

                                                                                                      10 mm = 100x

                                                                                                        9 mm = 111x

                                                                                                        8 mm = 125x

So as you can guess a 60mm telescope isn't a serious planetary scope. Venus present a challenge, for the first time ever in this telescope I saw chromatic abbreviation. Owing to Venus being so bright. Venus phase was half of the disc. Because of the chromatic aberration in the image, I decided to check if the telescope was perfectly collimated, as I was so surprised. Collimation was perfect. So then I changed eyepiece to check the eyepiece wasn't inducing some colour. It wasn't the eyepiece. Interestingly the Japanese 9 mm 0.965" Huygens eyepiece I used last night did not show anymore colour than either my Orthoscopic or Brandon eyepieces last night. I did do a direct comparison of the Huygens 9 mm to a Orthoscopic 9 mm. 

So after observing Venus, I decided to pay attention to the constellation of Orion. And what lies within. I looked at the Orion Nebula, as expected there wasn't much nebulosity to be seen in a 60mm telescope. I could only really see nebulosity with the finderscope, 32 mm Plossl, and 15 mm RKE. I then looked at the Trapezium in the Orion Nebula. The 60mm picked up all 4 major components A, B, C, D. I used my 8 mm Brandon and Edmund 8 mm RKE on the trapezium. With the seeing condition, a magnification of 125x and exit pupil of 0.48 mm. This was a challenge to see component B of the trapezium at times. Here I did a comparison between the  8 mm Brandon and 8 mm RKE. I was trying to gauge light through put, technically the RKE should let more light through owing to less glass in the design. At times I thought the RKE let through more light in moments of very good to excellent seeing. At other times I thought they were on par. I will have to do more tests. So what magnitude is the B star of the trapezium? Well Orionis B is a variable star and varies in brightness from 7.90 to a minimum of magnitude 8.65. 

After looking at the trapezium, I decided to practice my star hopping, So I star hopped to Betelgeuse, Meissa, Bellatrix, Tabit AB, Pi 2 Ori, Pi 4 Ori.

After that I then went to have a look at the Pleiades. 

So in all a busy little session. In my next session I will probably look for double stars, and practice my star hopping more. Until the planets show later in the year.

David

Edited March 27, 2020 by Dave1

[Ciaran Meier]

That's a crack'n looking scope there and a nice range of EP's too. 

Ciaran. 

[Dave1]

So guys I went back out on the 27/03/20 to observe. The telescope I used my Skylight 60mm F16.7. I spent more time on Venus, and spent some considerable time looking at the moon, looked at the Orion Nebula and the Trapezium. I looked at a couple of double stars, which I've not looked at before. I continued the comparison between my Brandon 8 mm and Edmund RKE 8 mm eyepiece. I also compare a 6 mm Huygens to a 6 mm Ortho. I even used a 4 mm Ramsden. Tonight I also used a Baader Semi APO filter and a TAL moon filter. Seeing conditions were generally very good to excellent, and more stable compared to the previous night. Pickering 8 to 9.

Eyepieces I used tonight were the magnification of the additional eyepieces are 6 mm = 167x

                                                                                                                                               4 mm = 251x

On Venus tonight I started off using my Baader Mk III 8-24 zoom eyepiece, with the moon filter fitted. The view of Venus was much improved, was sharper, less glare. I then went to a 10 mm Plossl. With the 10 mm Plossl I tried the Semi APO filter aswell as the Moon filter. The Semi APO was also an improvement compared to no filter at all. I preferred the view with the moon filter on Venus. I then used the 8 mm RKE with Moon filter. Put up a nice image, I spent a lot of time, trying to see if the 60mm would show me any details. I saw none or very very subtle hints, but not enough I'd be sure to sketch it.

I then moved onto the Moon, I started with the 10 mm eyepiece with moon filter. Was a good view, believe or not I've never used my moon filter before on the moon! I then compared my 8 mm eyepieces on the moon. Both put up very good views, I didn't feel either eyepiece had an advantage over the other. I then thought with seeing conditions being so good, to try higher magnification. So I went and got my 6 mm Huygens, Ortho 6 mm, 4 mm Ramsden, and  4 mm Ortho. All eyepieces put up very good images due to a excellent lens in the telescope and owed to the seeing conditions. The Huygens and Ramsden eyepieces have quite a narrow field of view, but this does not bother me to much. At there respective magnifications of 4 mm and 6 mm I preferred the 4 mm Ramsden and 6 mm Huygens to the Ortho eyepieces. The areas of the moon I did this comparison was Mare Crisium and Cleomedes. At times using the 6 mm and 4 mm eyepieces was a challenge owed to the small exit pupils and floaters in my eyes. 

I then observed Orion Nebula and the Trapezium. With the better seeing conditions tonight, which were more stable, I was better able to compare my 8 mm eyepieces. Tonight I definitely thought the Edmund 8 mm RKE, had slightly more light through put. I swapped the Brandon and Edmund back and forth multiple times. And it was always the same result, the B component was brighter in the 8 mm RKE.

So tonight I looked at some new to me double stars. I looked at Gamm1 and Almach in in Andromeda, and Miram in Perseus . So I am new to hunting down double stars in general, I have obviously in the past looked at Polaris, the double double, and Albireo. When I looked at Miram I thought the difference in magnitude of the stars I could see was a good opportunity to compare my 8 mm eyepieces. This confirmed my earlier findings, that the 8 mm RKE has more light through put. I can't wait now to see how the battle of the 8 mm eyepieces will play out when observing Jupiter. So I came in side and did some more research on Miram. Turns out Miram is a variable double star that has 6 components. I will be spending more time on Miram.

In conclusion a very enjoyable session.

David

Edited March 28, 2020 by Dave1

[Size9Hex]

Great reports. It’s nice to hear your experience and enjoyment with a 60mm scope. It must be smashing on double stars. My grab and go is a only a touch larger at 72mm, although much shorter focal length. You’ve inspired me to have another look through it soon (because actually, although it’s grab-and-go, my laziness has pushed me down to an even more grab-and-go-able pair of binoculars recently!). One of aspects that appeals to me on smaller apertures is that you can observe to the absolute limits of the instrument and observer.

[Dave1]

Thanks for the kind comments. Yes it is smashing on doubles. I once let a astrophotographer look through it at Mizar and Alcor. Due to its long focal length. And the quality of the optics. He said it was one of the best views of Mizar and Alcor he had ever seen through a telescope.

Glad I've inspired you. 

David

Edited March 28, 2020 by Dave1

[Stu]

8 hours ago, Size9Hex said:

One of aspects that appeals to me on smaller apertures is that you can observe to the absolute limits of the instrument and observer.

Absolutely agree with this! One of the reason I like small refractors; my little Telementor is great fun for those reasons.

@Dave1 lovely looking setup you’ve got there. I bet the views of doubles are cracking when the conditions are good. I love the bullseyes on black presentation of the airy disks at high power.

[Dave1]

@StuYep nothing beats white on black. Haven't looked through a Telementor yet, I hope to one day!