Mercury and Venus 20th May

[CraigT82]

I didn't think I could ever find Mercury in the blue sky (not having goto) but with it being currently close to Venus I thought I'd give it a go. I blocked off the sun using a parasol and found Venus fairly quickly in the finder, and shot off 30,000 frames with the Baader IR685nm filter, Altair 290mono and APM 2.7x barlow.

Then using a 30mm plossl in the main scope, scanned around the area Mercury should be by manually panning the scope around, using Venus as a starting point.  Took about 20 mins before I finally spotted it in the eyepiece (couldn't see it at all in the 9x50 finder).  Swapped over to the camera and captured 200,000 frames at 305 fps with the IR685nm, stacked 10%.

After capturing the videos I put an 8mm BST in and spent a while observing Mercury visually, as it was the first time I'd ever found it!  Showed the wife the view too who was very impressed.

 

[Paul M]

Your'e starting to make it look easy!

[John]

Great result Craig !

Makes my crude mobile-at-the-eyepiece efforts look pretty poor but, hey, it's been fun trying and seeing the phase of Mercury in a scope is a rare occurrence 

[Star101]

A great comparison. 

I think Friday night they will be horizontal to one another. A bit further apart than how you display though lol.

But you do show a great comparison of apparent viewable size difference. 

Think yourself privileged. I think most astronomers have never seen Murcury with their eyes   

I did image the transit a few years ago, but never seen with my eyes.

[Mark at Beaufort]

That is brilliant Craig. I have just been observing Venus and Mercury with Heritage 130P.

[CraigT82]

Was absolutely delighted when I finally found it, almost gave up several times as I was sure I wouldn't spot it! 

Gotta say though that Mercury is very nice to observe due to it's rarity of occurrence but this current phase of Venus in the blue sky is one of the most beautiful things to see in a telescope. 

[Stu]

Excellent shots Craig. That telly shows the size difference doesn’t it? Really nice results. I picked them both up around 8.15pm in binos, then managed to get the scope on them soon after.

[miguel87]

I got the scope onto mercury too but the seeing was awful, obviously it is low but I had a huge amount of atmospheric CA and a VERY jumpy planet too. No hope of surface detail.

Is this standard or can you catch it on better days. I dont know how good it gets?

[CraigT82]

8 hours ago, miguel87 said:

I got the scope onto mercury too but the seeing was awful, obviously it is low but I had a huge amount of atmospheric CA and a VERY jumpy planet too. No hope of surface detail.

Is this standard or can you catch it on better days. I dont know how good it gets?

This is the first time I've tried to image Mercury so not sure on how good it gets.

I got it at about 6.15pm when it was still at about 38 degrees so fairly high, I think others try to get it around midday when it's up at around 60 degrees. 

[miguel87]

29 minutes ago, CraigT82 said:

This is the first time I've tried to image Mercury so not sure on how good it gets.

I got it at about 6.15pm when it was still at about 38 degrees so fairly high, I think others try to get it around midday when it's up at around 60 degrees. 

Ah ok, I dont have goto or anything so had to wait until I could find venus naked eye and go from there. Was half an hour after sunset by the time I got it in the scope.

Thanks 👍

[Stu]

17 minutes ago, miguel87 said:

Ah ok, I dont have goto or anything so had to wait until I could find venus naked eye and go from there. Was half an hour after sunset by the time I got it in the scope.

Thanks 👍

If you make sure you block the sun off somehow (behind a building say) then sweeping for it with binoculars which are preset to infinity focus works pretty well. Same with trying to find it in your scope, have it preset to the correct focus and that makes life so much easier. Once you find it in binoculars it is easier to estimate the position and get it in the scope finder.

[John]

I used a 30mm optical finder to put the scope where I knew Mercury to be, but I could not actually see it with the finder. I actually "found" it using the scope at low magnification.

If you know the separation and approx orientation between an easy to find and a harder target, the defined field of view of finders (6 degrees in the case of my 30mm) can make finding things easier, or at least getting to the right spot, even if they are not actually visible in the finder.

I find Stellarium and Cartes du Ciel very useful for helping with this process. CdC has a handy distance measuring tool to help preparation. Maybe Stellarium does as well ?

 

[Stu]

1 hour ago, John said:

I find Stellarium and Cartes du Ciel very useful for helping with this process. CdC has a handy distance measuring tool to help preparation. Maybe Stellarium does as well ?

 

I suspect Stellarium can do this too but don’t know it well enough to tell.

Skysafari can do simple field of view circles based on the kit you put in, and can also measure the distance between two objects. This is the picture for 8.30 last night. I picked Mercury up fairly easily in the Genesis but then I did have over 5 degrees of sky to play with, so as John says, knowing where it was in relation to Venus made it much easier to find. Tonight should be much easier I would think as they are much closer.

[maw lod qan]

Your images are spectacular Craig.

I fought a small band of fair weather clouds coming in off the Gulf of Mexico so got very little time to view both planets before Mercury disappeared. 

Maybe tonight and tomorrow night I'll have more time. 

[johnturley]

I rely on 1980's technology to find Mercury and Venus in daylight, by setting the meridian pointer on my mount to local sidereal time. I do have an actual clock (see photo) although nowadays I use an iPhone app, which is probably more accurate.

Simply set the meridian pointer on the mount to sidereal time, and the RA and Dec  circles to the RA and Dec of Venus, Mercury, or the object you are trying to find (obtained from astronomical tables or an app such as  Skymap Pro or Stellarium). I found both Venus (which is a lot easier, and was also visible in my finderscope), and Mercury yesterday within a few minutes (see attached photos). I know that these photos do not compare to some which others have posted, but they are both single shot unprocessed JPEG images. 

A few points worth noting :

1) The mount needs to be more or less in a permanently aligned position.

2) You do require large and fairly accurate setting circles which most current mounts available do not have.

3) You do also require a 'driven' RA circle, i.e. one which continues to point to the same RA position as the drive slowly moves the telescope.

4) Ideally you need to the eyepiece you are using to find them in focus before you start looking, if you are only slightly out of focus, then you can't find them, and having parfocal eyepieces are a great help when switching to a higher power eyepiece .

A word of caution as well if you are looking in daylight, and have an open or partially open tubed Newtonian. Yesterday when looking at Venus, I became aware of something warm on my cheek, it was due to off axis light from the sun being reflected off the main mirror, even though the telescope was pointing to a position about 20 degrees from that of the sun. I solved the problem by sliding back the roof of my observatory shed so as to cut off the sun's rays. 

John

Edited May 22, 2020 by johnturley

[Star101]

That's great info John.

Just remember, those who will be looking, SAFETY FIRST!!!!

DO NOT LOOK AT THE SUN. especially with plain optics. One glimpse can damage your eye's PERMANENTLY!!  

[Pete Presland]

Nicely captured.

[johnturley]

I don't know whether it was an optical illusion, but observing the wafer thin crescent Venus only 6 degrees from the Sun at 17.00 hrs today, I got the distinct impression that I could see a faint ring of illumination all the way round the Venusian disc. In addition the mainly unilluminated disc appeared a slightly darker shade of blue than the background sky.

John 

[miguel87]

21 hours ago, johnturley said:

I don't know whether it was an optical illusion, but observing the wafer thin crescent Venus only 6 degrees from the Sun at 17.00 hrs today, I got the distinct impression that I could see a faint ring of illumination all the way round the Venusian disc. In addition the mainly unilluminated disc appeared a slightly darker shade of blue than the background sky.

John 

I believe this is known as the 'ashen light'. It is debated as to whether it is real or an optical illusion. I have never seen it myself but many have.