Solar guiding - first test of PHD2.planetary on AR3685

[Rob63]

First of all, why would you want to guide on the Sun?
Well its very handy for those long animations of an active region or prominence. I typically have to re-adjust my framing every few frames and over the course of a couple of hours this can become a pain, and you end up with drift causing the loss of part of the image when stacking.
I had looked into the Hinode solar guider but it's been out of stock in the UK for a while and it is expensive, so when the phd2.planetary project came along I was very interested, this is a custom version of phd2 for solar, lunar, and planetary imaging.
The project is still in beta testing and the version I used was RC5 so they are getting close to a full release.

I made a filter with Baader solar film ND5 for my guidescope and tested exposures with an ASI120MM I had lying about doing nothing. The image was far too bright at minimum exposure & gain so I added a continuum filter on the camera nosepiece which got me a useable result although the exposures were still surprisingly short at 5ms

I am very familiar with phd2 for seep sky imaging so I found things quite easy to set up, there is a guide at https://github.com/Eyeke2/phd2.planetary/wiki The only new bit was a button beside the "brain button" (with a sun/moon icon) which allows you to configure the Edge detection threshold and a "time lapse" which stops phd2 trying to make adjustments at the solar exposure rate. Essentially, phd2 will check guide position every (exposure_rate + time_lapse)ms, In deep sky, you'd be aiming between 0.5s and 5s depending on the mount type. I tested this with a 1000ms timelapse.

I had a nice sunny day for testing on Saturday the 18th although the seeing wasn't great and noticeably deteriorated during the test run of 1hr 50min.
There wasn't a huge amount of action going on but I did catch a nice little flare.
Setup was a skywatcher ED120, Quark chromosphere and ASI174MM with a Baader 35nm Ha filter as an internal ERF.
Guidescope was an Astro essentials 60mm with an ASI120MM.
Mount was a ZWO AM5

To cut this short, it works, and it works well, I am sure there is room for improvement as I tinker with the settings but my 120mm rig stayed bang on target for the near 2 hours of my run without any intervention from me. The guide figures wouldn't be acceptable for deep sky but are fine for Solar.
Thanks to all involved in the project, you have done a fantastic job.

As a bonus it has saved my £750 on buying a Hinode so does it replace a Hinode?
Not necessarily, if you want to be as mobile as possible or don't want to be running a laptop or carry a guide scope with 2nd camera etc.
If, like me, you just work from a "garden observatory" phd2,planetary is ideal.

The setup

Guiding

The test target was AR3685 start time 09:35, End time 11:24 (UT)

[Dave Smith]

Thank you. That is VERY interesting, and a lovely animation to go with it.

Dave

[LukeTheNuke]

Hmmm, interesting. Good point about animations over a long period of time.

[Hals]

Excellent write up and results, it looks very promising. Thanks for the heads up.

[Leo Shatz]

Hi, I'm Leo, the developer behind the new PHD2 functionality for solar and planetary guiding. Over the past few months, I've shared updates about my beta program on several astronomical forums. While adoption has been gradual, I'm pleased to see that more users are finding it useful, especially among solar imagers.

I'm excited to announce a new feature I'm working on that enables capturing image sequences and PHD2 guiding on the Sun, Moon, or planets using just the main scope and its camera. This eliminates the need for a separate guidescope or OAG with a dedicated guiding camera. Although I can't specify a release date, here's a teaser: 

A 3-hour timelapse of the lunar surface changing from 79.5% to 80.1% illumination

Here are two more time-lapse video clips made with the same software setup (no dedicated guiding camera): 

Time lapse of X3.9 solar flare in AR3664 - May 10, 2024

A time lapse of moving shadows on Moon

[skybadger]

I'm slightly confused 

I've been trying just this with the existing auto guiding capability of phd2 on the AR3664 and having not great success with the Nyx mounting it's on. 

It's been able to lock onto the spot fine but still not achieving a fine lock. Also it's not been correcting all the error. Is this because it's just not the right tool for a solar disk ?

I will give this a go but would like to understand whether this will be a feature of mainstream phd2 {desired} rather than a stand-alone 

Cheers

 

 

[skybadger]

On 20/05/2024 at 20:41, Rob63 said:

Guiding

Are you guiding on a separate imager in this picture . Does this work by guiding on the high Res high scale picture from the main imaging camera ?

[Leo Shatz]

3 minutes ago, skybadger said:

I'm slightly confused 

I've been trying just this with the existing auto guiding capability of phd2 on the AR3664 and having not great success with the Nyx mounting it's on. 

It's been able to lock onto the spot fine but still not achieving a fine lock. Also it's not been correcting all the error. Is this because it's just not the right tool for a solar disk ?

I will give this a go but would like to understand whether this will be a feature of mainstream phd2 {desired} rather than a stand-alone 

Cheers

 

 

You'll need to download a beta version of PHD2 with solar and planetary guiding. It's currently available on Windows platform only: https://github.com/Eyeke2/phd2.planetary/releases/tag/v2.6.13-planet.dev7.rc5

Make sure to read the Wiki pages: https://github.com/Eyeke2/phd2.planetary/wiki

Clear skies,

LS.

[skybadger]

Thanks. So you think the two versions will be combined ? 

I read with interest the use of the guiding assistant to adjust polar alignment. Is this also possible I the standard version, say using a limb of the sun to identify drift ?

[skybadger]

Sorry. I am talking rubbish when I say I've been trialling normal phd2 as a  solar guider, actually I've been trialling firecap as the solar guider. 

Don't know where my brain went to there. 

[Leo Shatz]

1 hour ago, skybadger said:

Thanks. So you think the two versions will be combined ? 

I read with interest the use of the guiding assistant to adjust polar alignment. Is this also possible I the standard version, say using a limb of the sun to identify drift ?

Yes, the GA can be used to fine tune PA when using PHD2 solar/planetary guiding. It can be sometimes tricky, but if there is no other choice, it can be helpful.

[Rob63]

14 hours ago, skybadger said:

Thanks. So you think the two versions will be combined ? 

It's a possibility but would depend on the developers.

phd2.planetary is a fork of the main phd2 codebase, this means that it has all the same features as "normal" phd2 and can be used for DS imaging as normal.

The Wiki gives instructions on installation i.e. you should install in a separate folder and run phd2.planetary as a 2nd instance which means that it wont affect your  "normal" phd2 settings

14 hours ago, skybadger said:

Are you guiding on a separate imager in this picture . Does this work by guiding on the high Res high scale picture from the main imaging camera ?

It works with the guide scope/camera in exactly the same way as "normal" phd2 for dark sky (see first photo)

[skybadger]

5 hours ago, Rob63 said:

It works with the guide scope/camera in exactly the same way as "normal" phd2 for dark sky (see first photo)

Thanks. This arose because if got confused with Firecap. I shall give it a try directly.