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AEAJR
07-10-2017, 09:17 AM
How many ways are there to locate targets? What is your favorite?

As a newbie, one of my greatest concerns was whether I would be able to find things. I had some success with star hopping with binoculars but when I got my first telescope I selected a GoTo mount. I am very happy with my decision. But I have since learned other techniques.


So I was wondering as to how many ways there are to find targets and interested in what people like best.

Here is what I know of so far:

GoTo – fully computerized including finding and tracking.

PushTo – Computerized help in finding targets but no tracking

Star Hopping – Start at a bright star then go there and go there and you should be on it. (like turn by turn directions in your car) Usually worked out on a paper chart or with a computer program to work out the steps of the hop. If you can see the guide stars and confirming patterns this should work well.

Setting circles on an equatorial mount – Uses Right Ascension and Declination coordinate system that is unique to astronomy – can read coordinates from a paper chart then use the setting circle dials on the telescope to point the scope.

Altitude and Azimuth – Height above zero angle and a degree angle from North. I think this is best worked with a real time program on computer or phone to provide the coordinates as these change constantly.

Those are the ones I know of. Are there others?


I have used:

GoTo – Meade ETX 80 and ETX 125 – Love it!

PushTo – Orion Intelliscope- Love it!

Star Hopping – Most success with binoculars and bright targets. Less so with my telescopes in most of my very light polluted sky as I can't see many of the stars I would like to see in order to do the hop or to see the pattern that would confirm I am in the right place.

AltAz coordinates – Tried this recently using a digital angle gauge for the altitude. Used Star hopping to approximate azimuth position. Have not tried using a compass or an azimuth degree gauge on the scope.

Never tried setting circle dials on an EQ mount.


Are there others?

Which do you use?

Which do you like?

The Mekon
07-10-2017, 09:30 AM
The most satisfying is star hopping. Used it for many years to find many hundreds of objects. Essential is a good finder or "hopping" scope. I used (and still do use) a 15 x 60mm correct image 45 degree finder) This makes life a lot easier tracing the star patterns that I note from Sky Atlas or Uranometria.

Since 2009 and buying a goto mount I don't use the star hopping as much as I use to. What I do sometimes is to use goto to send the telescope to a catalogued object (NGC, IC etc) then use hopping techniques to get to a nearby uncatalogued object.

With my 18" I mainly use push to on the Argo-Navis. The goto servo motors take longer to get the object in the field of view.

peter_4059
07-10-2017, 09:38 AM
Plate solving is the easiest.

alocky
07-10-2017, 01:05 PM
With the imaging setup I use goto. For visual, even through the big dob, if it's the first time I've ever looked at an object I make a point of star-hopping. Even though I need to use a ladder to get up to the finderscope, I use a telrad to position the scope and ladder. Under a dark sky it's also a wonderful way to re-acquaint yourself with some of the dark corners of forgotten constellations.
A couple of my observing buddies and I have a bit of a ritual with people who want to share our dark sky site. They have to star hop to Shapley-1 before they're invited back.
If I'm just showing people around, or trying to get as many visual supernova searches done as I can, it sure saves a lot of time and faff using the servocat and argonavis.
cheer,
Andrew.

AEAJR
07-10-2017, 02:53 PM
Not familiar with this one. Is this come kind of AP tool?

peter_4059
07-10-2017, 03:04 PM
yes it needs an image, a goto mount and a computer.

The Mekon
07-10-2017, 06:56 PM
A bit of a flippant remark Peter, to a well composed post by Ed the OP.
Best to keep to the topic I think.

John

peter_4059
07-10-2017, 07:09 PM
Hi John,

Not sure how you have concluded I was not sticking to the topic or how you came to the conclusion my post was flippant.

Ed has a goto mount and has posed the question "how many ways there are to find targets and interested in what people like best"

He says "Here is what I know of so far: GoTo – fully computerized including finding and tracking." He says "I have used: GoTo – Meade ETX 80 and ETX 125 – Love it!"

His questions are:
Are there others?
Which do you use?
Which do you like?

Do you consider the fact that I prefer plate solving outside the scope of his questions?

croweater
07-10-2017, 07:19 PM
Hi Ed. I believe you take an image and there is sofware that will compare your image to charts and adjust your telescope position accordingly. Needs computer controlled scope. I think you can also do it manualy by camera liveview (to get PA) and just keep adjusting to get closer to pole by noting the star trails. I think Alex (Axelnave does this). Cheers Richard.

AEAJR
07-10-2017, 07:50 PM
No problem guys. I had heard of plate solving but had no idea what it was or how it worked. Perfectly valid for the discussion.

And thanks to everyone who has responded so far. Very interesting responses.

I am always looking to understand how others enjoy this hobby, and I am always looking to learn new things. For IIS this becomes more interesting since most of you are half a world away from me in the USA. Common practice may be different there.

The Mekon
07-10-2017, 08:14 PM
Peter, if you can do this "live" during an observing session, then yes your method is spot on topic, and I have learnt something! (and I apologise).


Perhaps give us a few more details?

peter_4059
07-10-2017, 08:31 PM
Sure John.

I and many others on this forum use plate solving to point the telescope to the desired target "live". Plate solving is so good you can return to the same target within a few pixels on a camera field night after night. There are many free plate solving options including Elbrus and Astrometry available to amateur astronomers.

I notice you use the word "observing" in your last post. You obviously can't plate solve without taking an image which I clarified in my response to Ed however I also note Ed did not specify "observing" as a consideration in his question.

If you would like some help to get started with plate solving I'd be happy to point you in the right direction.

AEAJR
08-10-2017, 02:01 PM
It is true, I did not specify visual astronomy. I was not aware that AP had special methods for finding targets. See, you learn something new every day. :D

glend
08-10-2017, 02:18 PM
Goto mount precisely polar aligned. As an imager i realise plate solving is an important crutch to many, but i don't use it and consider it a lazy approach. I have no problem getting back to the same target orientation, night after night. Being a few pixels out is not an issue as it gets fixed in registration and stacking. Plate solving that requires internet access to work is useless at many dark sites.

peter_4059
08-10-2017, 02:36 PM
Hi Glenn. Many plate solving applications do not require internet access as the index files are stored on the pc. There is quite a choice including Platesolve2, Astrometry.net and Elbrus that all work standalone. I used to find targets the way you do but would rather spend my precious dark sky time imaging than trying to frame a target. Not sure what capture software you use however Platesolve2 and Astrometry.net are well integrated in SGP. Pixinsight are also working on telescope control capability and PI also has platesolving capability.

RobF
08-10-2017, 02:44 PM
I hadn't thought about using platesolving for casual observing, but it wouldn't take much to have the laptop, connection and a small guidescope with a suitable camera.

For imaging, its almost indispensable - the ultimate "sync" and pointing model correction. Seems like cheating, but agree with Peter its all about maximising dark sky time really.