Jupiter, GRS and Europa

[Piero]

Overall, it was an interesting session. Thanks @Stu for the heads up! I was hoping to have a quick session on a couple of planetary nebulae tonight but the transparency is just not sufficient. So, Jupiter got full attention!  I also caught the opportunity to test a bit more my Delos 8mm vs Vixen SLV 9mm. Their views are generally comparable, but... well, I described below.. Hopefully somebody with more experience than me can let me know how to call that effect. 

Thanks for reading, 

Piero

 

Date 03/05/2016
Time 21:30-22:40
Lunar Phase Waning crescent 9%
Temperature 9C (SSW 5 km/h)
Seeing 1 - Perfect seeing
Transparency 3 - Somewhat clear
Darkness 19.4 (when lights off)
Telescopes Tele Vue 60 F6
Eyepieces Delos 12, Vixen SLV 9, Delos 8, PM2.5x
Filters Single polarising filter (SPF)

Jupiter - Planet 75x, 100x, 112x +/- SPF
Despite a very good seeing, transparency was affected by high clouds. In the beginning of this session, a true beacon of light coming from the neighbour's garden almost blinded me. Unfortunately he had to work in the garden as he is moving out soon, so I could not really ask him to switch that light off. Thankfully the TV60 is very light and was placed in an area of the garden that was less affected by the light. Jupiter looked beautiful and I am convinced that if the transparency had been a bit better, many delicate features would have been observable more clearly, in particular festoons. The two main events tonight were the transit of Europa and the GRS. I was not able to spot Europa, but its shadow was visible without much difficulty. The GRS was well distinct and appeared like a darker, but not black, little area, at the centre of the South Equatorial Belt, before gradually moving towards East. The SPF enhanced the colour of the equatorial belts which appeared more vivid, and the shape of the GRS making 
its contour more noticeable. Regarding the eyepieces, my vixen 9mm SLV is quite sensitive to external light sources and bright targets on axis to me. This works as follows. As soon as Jupiter was approaching the centre of the eyepiece the light of the target spreaded in two opposite directions. After the target has passed that critical small area (few seconds), the image was fine again. I believe this was affected by the external light from my neighbour as the area changed slightly when the telescope was moved. However, after careful examination, I noticed that the beams rotated accordingly as the eyepiece was rotated suggesting that there could be a bit poor light control for bright targets to me. This effect was repeatedly visible on Jupiter tonight, but I have not ever noticed anything similar on other bright targets like the Sun or the Moon. Venus would be an interesting test of course. This effect is completely absent on both my 12mm and 8mm Delos eyepieces, and as far as I know I never noticed it on my 
Vixen SLV 5mm.

[Helix]

I just finished observing transit of Europa and GRS   with 10". It was rewarding because as you mentioned already the sky is not great due to high level clouds. 

 

[DRT]

Nice report, Piero. It is amazing what you can see through that beautiful little scope and every time I see your reports of using it I am tempted to buy one

[Piero]

5 minutes ago, DRT said:

Nice report, Piero. It is amazing what you can see through that beautiful little scope and every time I see your reports of using it I am tempted to buy one

Thanks Derek

Every time I see Mike's sketches I would be tempted to get a Tak100 instead! Eventually we have what we have and the best thing, I think, is to get the most out of our nice toys.

[t0nedude]

Excellent report Piero!

[jetstream]

Great report Piero and a very interesting observation about the 9mm SLV. In bright sunlight does the SLV eyelens look "black" or a deep color? Does it "eyeball ghost"? Some say looking at the coatings from the eyelens side says nothing about the coatings for astro use as light enters the other end. However some coatings (or lack of) can cause issues from external lights when observing at night, inducing scatter among other things. As a smallish bright object is observed at the same time multiple problems might arise. Just a guess.

[andrew63]

Thanks for the detailed observations. It was a bit hazy here, but had a look at jupiter from the heads up from Stu.  At 95x in the little achro i could discern the GRS - as a darker region as in your description. The globe or detail is not great though, but the haze helped with some of the colour halo.   

 

andrew

[Piero]

5 hours ago, jetstream said:

Great report Piero and a very interesting observation about the 9mm SLV. In bright sunlight does the SLV eyelens look "black" or a deep color? Does it "eyeball ghost"? Some say looking at the coatings from the eyelens side says nothing about the coatings for astro use as light enters the other end. However some coatings (or lack of) can cause issues from external lights when observing at night, inducing scatter among other things. As a smallish bright object is observed at the same time multiple problems might arise. Just a guess.

Thanks Gerry and for giving me a potential clue about what is going on!  

I will look into this at home this evening. What do you mean by "eyeball ghost"? the reflection of the eyeball?

[laudropb]

Very nice report Piero. Lots of clouds here last night, but I did manage a few nice views of the events on Jupiter in between the clouds.

[mikeDnight]

9 hours ago, Piero said:

Overall, it was an interesting session. Thanks @Stu for the heads up! I was hoping to have a quick session on a couple of planetary nebulae tonight but the transparency is just not sufficient. So, Jupiter got full attention!  I also caught the opportunity to test a bit more my Delos 8mm vs Vixen SLV 9mm. Their views are generally comparable, but... well, I described below.. Hopefully somebody with more experience than me can let me know how to call that effect. 

Thanks for reading, 

Piero

 

Date 03/05/2016
Time 21:30-22:40
Lunar Phase Waning crescent 9%
Temperature 9C (SSW 5 km/h)
Seeing 1 - Perfect seeing
Transparency 3 - Somewhat clear
Darkness 19.4 (when lights off)
Telescopes Tele Vue 60 F6
Eyepieces Delos 12, Vixen SLV 9, Delos 8, PM2.5x
Filters Single polarising filter (SPF)

Jupiter - Planet 75x, 100x, 112x +/- SPF
Despite a very good seeing, transparency was affected by high clouds. In the beginning of this session, a true beacon of light coming from the neighbour's garden almost blinded me. Unfortunately he had to work in the garden as he is moving out soon, so I could not really ask him to switch that light off. Thankfully the TV60 is very light and was placed in an area of the garden that was less affected by the light. Jupiter looked beautiful and I am convinced that if the transparency had been a bit better, many delicate features would have been observable more clearly, in particular festoons. The two main events tonight were the transit of Europa and the GRS. I was not able to spot Europa, but its shadow was visible without much difficulty. The GRS was well distinct and appeared like a darker, but not black, little area, at the centre of the South Equatorial Belt, before gradually moving towards East. The SPF enhanced the colour of the equatorial belts which appeared more vivid, and the shape of the GRS making 
its contour more noticeable. Regarding the eyepieces, my vixen 9mm SLV is quite sensitive to external light sources and bright targets on axis to me. This works as follows. As soon as Jupiter was approaching the centre of the eyepiece the light of the target spreaded in two opposite directions. After the target has passed that critical small area (few seconds), the image was fine again. I believe this was affected by the external light from my neighbour as the area changed slightly when the telescope was moved. However, after careful examination, I noticed that the beams rotated accordingly as the eyepiece was rotated suggesting that there could be a bit poor light control for bright targets to me. This effect was repeatedly visible on Jupiter tonight, but I have not ever noticed anything similar on other bright targets like the Sun or the Moon. Venus would be an interesting test of course. This effect is completely absent on both my 12mm and 8mm Delos eyepieces, and as far as I know I never noticed it on my 
Vixen SLV 5mm.

Hi Piero,

It might be an idea to use a blackout blanket even when observing the planet's, as it not only blocks the annoying light but also helps increase contrast and definition. Even low amounts of light entering your eye from your surrounding environment acts like noise to disrupt the view. Also, it sounds to me like you might have oil from your eyelashes on your eyelens, as the beams you spoke of rotate with the eyepiece. It might be worth giving them a clean to see if it gets rid of the problem. Great report by the way!

Mike 

[Piero]

Just now, mikeDnight said:

Hi Piero,

It might be an idea to use a blackout blanket even when observing the planet's, as it not only blocks the annoying light but also helps increase contrast and definition. Even low amounts of light entering your eye from your surrounding environment acts like noise to disrupt the view. Also, it sounds to me like you might have oil from your eyelashes on your eyelens, as the beams you spoke of rotate with the eyepiece. It might be worth giving them a clean to see if it gets rid of the problem. Great report by the way!

Mike 

Thanks Mike  

I will try the blanket! Thanks for the suggestion. Not sure about the oil on the eyelens as the eyepiece was bought recently and I generally observe with the "lens shield" fully up. It could be that they need a clean anyway. Now that you said this, my 5mm was actually cleaned by me so this might be a reason why I don't see this effect on that eyepiece. Thanks for pointing this out.. I'll clean it with the baader liquid and see what happens.  

[Piero]

@jetstream  So, depending on the angle the coating are dark green or dark purple to me.  

[jetstream]

Can stray light "get in the eyepiece"? I have a short list of EP's used when there is stray light around.

[Piero]

It does not look like to me.. 

[John]

I've seen something like the effect described below in another eyepiece. It turned out that 2 lens elements which should have been separated were actually touching in the centre.

This caused the sort of effect that Piero describes just as the object in view passed through a small area of the FoV.

 

22 hours ago, Piero said:

.....Regarding the eyepieces, my vixen 9mm SLV is quite sensitive to external light sources and bright targets on axis to me. This works as follows. As soon as Jupiter was approaching the centre of the eyepiece the light of the target spreaded in two opposite directions. After the target has passed that critical small area (few seconds), the image was fine again....

[Piero]

11 hours ago, John said:

I've seen something like the effect described below in another eyepiece. It turned out that 2 lens elements which should have been separated were actually touching in the centre.

This caused the sort of effect that Piero describes just as the object in view passed through a small area of the FoV.

Thanks John for your comment . Yesterday I cleaned the eyepiece as suggested by Mike. If tonight will be clear, I will try it on Jupiter again and give an update on this.

The funny thing is that I only have this effect on Jupiter. Never seen anything like that on the Moon, the Sun, or any other target.  

[Piero]

Cool!!  It works like the 5mm now!!   There is no change in the image when the eyepiece is rotated and no beam of light from Jupiter is visible at any placement of the planet on the focal plane. I also simulated the introduction of external light with the torch application on my phone and the "beam effect" was not replicated. It just was not there. I then tested it by placing the telescope near a window with a light on inside simulating a naughty neighbour enjoying annoying poor astro amateurs, but again nada de nada, the beam effect was not there. Therefore I pointed at castor and Vindemiatrix and no beam effect. Finally I pointed at Jupiter again and replaced the 9mm with PM2.5x with my Vixen 5mm, and the little additional amount of light surrounding the planet was very similar and with identical shape. The 9mm works like the 5mm now apart from the lower magnification of course!  

Thanks Mike ( @mikeDnight ) a lot for the suggestion of cleaning the lens. The only explanation that comes into my mind is that it was not cleaned properly or with a cheap and bad product which eventually left a tiny layer of residual on the lens. With the air blower first and the Baader liquid later, it works great on all the field now. Actually, the image seems even a touch more accurate now.

Thanks everyone for your help with this!  

Piero