Mercury

[wookie1965]

Just watched Sky at Night Pete Lawrence was talking about viewing Mercury during the day. 

You do a 1 star alignment on the sun then goto Mercury. 

Now the question is can you do a 1 star alignment on the sun with a EQ5 if so how please. 

Paul 

[Carbon Brush]

I think the 'which buttons to push' answer  depends on the version of EQ5 controller. The age/revision and whether it is Skywatcher, Celestron, Meade, Bresser, etc.
The general principle would of course be to pop a solar filter on the front end of any scope. Or if suitable a Herchel wedge on the back.
Having centred the sun, slew to Mercury and remove the wedge/solar filter.

HTH, David.

[PeterStudz]

2 hours ago, Carbon Brush said:

The general principle would of course be to pop a solar filter on the front end of any scope. Or if suitable a Herchel wedge on the back.
Having centred the sun, slew to Mercury and remove the wedge/solar filter.

HTH, David.

I can’t help doing this with an EQ5 but I’ve used this method to locate planets during daylight with my 8” Dob - eg Venus, Jupiter and Saturn. One bit of extra advice is to focus when on the sun (solar filter on). Although aligning on the sun should have your planet in the finder it might be rather small and/or hard to see. So having a low power eyepiece on focus will make things easier. 

However, although I’ve had success with other planets Mercury failed every time I tried. I’m sure that I at least had the finder on Mercury but it was just too small/faint to see in daylight. If you get it to work please let me know! Although I think I’ll give it another try. 

[Space Hopper]

6 hours ago, wookie1965 said:

Just watched Sky at Night Pete Lawrence was talking about viewing Mercury during the day. 

You do a 1 star alignment on the sun then goto Mercury. 

Now the question is can you do a 1 star alignment on the sun with a EQ5 if so how please. 

Paul 

Why not use the moon if its visible ?

[Carbon Brush]

I have been thinking a little more on this one - but have not seen the programme.

The benefit of using the sun for alignment is that it is near to Mercury.
This means polar/level misalignment, or mount errors, result in a smaller error when slewing to Mercury.
The Moon could have a big separation from Mercury, allowing mount errors to be significant.
On the right days, the moon can be near to Mercury.

On focussing. Before startng, take note of a focus position for the planned eyepiece(s) looking at a distant horizon.
This can be done using a steel rule measuring focus position, an inbuilt focus ruler or a number of focus knob turns from the end stop.
This all depends on the focusser type. Of course if you are wealthy enough to own an electronics focusser......
A Baader film filter on/off won't shift the focus position. So a focus on the sun is OK.
At the other extreme, swapping a Herschel wedge for a digonal produces a huge path length difference requiring the check mentioned above.

Do let us know how you get on.

[PeterStudz]

40 minutes ago, Space Hopper said:

Why not use the moon if its visible ?

Yes, I’ve used the moon if visible. The sun plus the moon is worth doing as it’s significantly more accurate. However, usually the moon isn’t in the sky or (which has happened) stuck behind a tree

[wookie1965]

It is a Skywatcher V3 handset and a Celestron 120 xlt I have got a solar filter for it which I will use. I could use my Vixen 102 or the Tal 100rs and my Herschel wedge  but like you said  there is a big difference in focal length.

If I level the mount and point North using a compass I wont be far off polar aligned its the next bit I can centre the Sun but I am not doing a 1 star alignment so I dont know if the mount would no where it is to slew to Mercury.

This is supposed to be on the 4th of June and Jupiter will be close as well.

Edited May 14 by wookie1965

[Carbon Brush]

Another option is to use two scopes on the mount. If the mount will handle the weigth.
Though your scope selection and EQ5 may be pushing it.
Check the scopes are aligned to each other beforehand.
Scope A is set up for solar. Scope B is set up for 'dim' viewing and focus checked before the session.
Align to the sun using scope A, keeping scope B capped.
Slew to Mercury and uncap scope B.

Depending on how well the scopes optical and mechanical axes are aligned, you could align to the sun on Scope A.
Then slew to Mercury and swap to scope B using the dovetail fixing. don't disturb anything else.
You can check for the alignment in daylight on a horizon object.
Put Scope A on the mount and centre an object of interest.
Swap to scope B and see if the object is still centred.
If necessary, shove packing pieces (plastic/card) inside the tube rings to introduce a small angular shift.
Cheaper than buying guide scope rings😁

[bosun21]

Unfortunately the Synscan doesn't seem to have any facility for solar system alignment procedures unlike Celestron which does. You could use one of the apps like polar align pro and do as @PeterStudz has detailed. Focus is crucial as has been said.

[Cosmic Geoff]

I have often found planets in daylight using a Celestron SLT alt-az GoTo mount and (usually) aligning on the Sun.  Assuming the planet is suitably positioned, Venus can almost always be located, also Jupiter (not so easy to see).   Sometimes Mercury can be seen clearly once you get your eye in while at other times it just doesn't show. 

I have not tried using an EQ-5, but you would increase your chances by polar aligning and sky aligning it at night and leaving it 'parked' till the next day and then un-parking (etc) and using the Planet button.

[crush]

I use a WIFI dongle and the Synscan app and then do a 1 star alignment and the sun is the first star on the list, but i don't know if this would be the same on your hand controller.

[johnturley]

I use a sidereal clock (actually an app on my phone these days, although I do have an Astrotech sidereal clock), and setting circles, but you do need large accurate driven circles with a meridian pointer (which few mounts have these days), and an accurately aligned mount. You simply set the meridian pointer to the current sidereal time, and move the telescope so that the RA and Dec pointers indicate the position of Mercury. See attached photo of the RA circle and meridian pointer on my 40 year old Astro Systems fork mount.   

I find it fairly easy to find in daylight provided that Mercury is brighter than zero magnitude, it become increasingly difficult between zero and +1, and very difficult if fainter than +1. It is also easier to find early evening or morning than around midday, when incidentally viewing conditions are usually quite poor.

It is also important to leave the telescope in focal position for your favourite eyepiece. A set of parfocal eyepieces such as the T6 Naglers (which are also parfocal with the 19 and 24mm Panoptics) also helps. This is incidentally one advantage of the T6 Naglers over the ES 82's, the latter not even being approximately parfocal.

John 

Edited May 24 by johnturley

[crush]

Have to say it is impressive keeping your mount in good working order for that long.