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SkyTools works primarily on multiple star systems, not individual pairs.
#1
Hi,
I am now to the forum and I have posted my feedback here https://groups.yahoo.com/neo/groups/skyt...pics/15833, but this  forum is probably a better place.

I am using the SkyTool 3 for over a year now and I like this tool very much. This is not a new topic, but still I have some concerns.

>> SkyTools works primarily on multiple star systems, not individual pairs.
I understand it, but I do not really agree that this is the most convenient way to operate. At least not for me.

>> The Planner picks the pair that you are most likely to observe given your telescope and the observing conditions for the night selected.
Really - let us take an example:
Location: 54° 30′ 0″ N, 18° 33′ 0″ E
Time: Summer (June 2018)
Scope: Sky-Watcher ED120
Eyepieces: 4mm, 6mm, 10mm, 20mm, 33mm 
Star: 31 Cyg

Skytools suggests pair DE - the second component is 13.2 mag. Not visible in this scope at this time of the year. I added it to the list to observe AC: 3.8+6.9 mag with a wide 105" of separation but with a nice color difference.  

I know that this changes the architecture of your program, but giving the enduser the option to create a list where the user could work on individual pairs would be very beneficial.
I do ask to change the default behavior, but please provide an option (like separate list type).
I understand that different users have different expectations and usage models, so there are probably users that would like the tool to handle the logic, but some users (as me) prefer to have full control of their list.

Best Regards
Piotr
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#2
Hello,

Thank you for posting here. When I approved your original message on the Yahoogroup I suffered another browser exploit attack, likely via an advertisement. They are either unable to solve these problems or simply don't care. Either way, I need to shut that group down as soon as I have the time.

I searched and searched, but I was unable to find the original thread that you are referring to. As a result, I am unsure which parts you have quoted and which parts you have written just now.

It would appear to me that SkyTools is not working as intended for the example cited. This appears to be a failure of the algorithm, and I of course prefer to fix the algorithm rather than abandon the entire idea. Also, a double star in Cygnus not being visible in the summer makes no sense to me. It is the strength of SkyTools to calculate just that. I suspect that there is a fundamental problem, such as incorrect settings for the location or telescope, that is keeping SkyTools from correctly selecting the best pair. If this is your example, I urge you to take a look at your location settings (is your lat/long switched?, is your longitude negative when it should be positive?). Is your telescope data entered correctly, using the correct units?

Let is also remember that you are of course free to observe any pair in the system once you put it in the eyepiece.

That said, at some point in the past I committed to including the ability to select the pair to be displayed in the planner, so that will be a feature of SkyTools 4.
Clear skies,
Greg

SkyTools Developer
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#3
Hi,
Thank you for your prompt replay.

Quote:I am unsure which parts you have quoted and which parts you have written just now. 
Do not worry I just wanted to let you know that I have posted the question on on Yahoo, too.
All quotes are in Italic, but everything is needed is in this post.

Quote:Let is also remember that you are of course free to observe any pair in the system once you put it in the eyepiece. 
Yes I remember, but this is not my usage model.


Quote:That said, at some point in the past I committed to including the ability to select the pair to be displayed in the planner, so that will be a feature of SkyTools 4.
That is a great news - thank you.


Quote:I suspect that there is a fundamental problem, such as incorrect settings for the location or telescope, that is keeping SkyTools from correctly selecting the best pair.
And I suspect this is a problem with the algorithm.
I have done screen shots of the important settings (not attaching the eyepieces as I can attach only 5 files) so you can point out where my settings are wrong. Or you can use this info and try to reproduce the suspected issue on your side - it should just take less then 10 min.

I use the standard edition version 3.2k DL SE.
If you need more info from my side do not hesitate to ask.

Best Regards
Piotr


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#4
Isn't the west longitude suppose to be set for + and not -18 degrees?
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#5
(2018-06-28, 12:10 AM)Cometstalker Wrote: Isn't the west longitude suppose to be set for + and not -18 degrees?

Not for Poland. That would be negative because it is toward the east.
Clear skies,
Greg

SkyTools Developer
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#6
Quote:Isn't the west longitude suppose to be set for + and not -18 degrees?
Yes you are right (https://en.wikipedia.org/wiki/Gdańsk) - but this is a predefined location by SkyTools. This should be be fixed to.

I have changed the location to Warsaw (the coordinates are correct), but this does not change the original issue.


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#7
I am sorry but you are mistaken. Some people believe that East longitudes are standard, and indeed we often see longitudes written as positive toward the east (as measured from Greenwich). But in fact, longitudes can be measured in either direction, and the only real standard is that you must state which direction it is being measured in.

The Wiki page provides a longitude that is measured toward the East (see the "E" after the number). So it is positive in Europe.

SkyTools 3 asks for longitudes measured to the west, which means that they are positive in the western hemisphere and negative in Europe. So it is a negative number.
Clear skies,
Greg

SkyTools Developer
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#8
By the way I no longer believe this is a problem with the algorithm. I think it is a database issue related to the magnitude of the secondary component in the DE pair. It is a very big task to bring all of the different pairs into a single system (regardless of whether you understand the utility of doing so) for hundreds of thousands of stars. Very different magnitude data are often presented for the same star from different sources. I believe what is going on is that SkyTools is using a brighter magnitude for the E star than the one that is being displayed. This can happen because there are ultimately two separate databases that the data is stored in. Normally both databases would have the same magnitude, but in some rare circumstances they hold a different number, having to do with the way the database was built, and how terribly inaccurate the WDS catalog was at the time (and still is, really).

In fact, I suspect that that DE pair is a duplicate observation of AB pair, likely the result of an erroneous observation included in the WDS. My algorithm that built the database attempted to fit the data from the UCAC and other catalogs to the WDS and this is what it came up with.

There are two ways to look at double star catalog errors. You can get upset that the data isn't perfect and tell me I should fix it, or you can see it as an opportunity to do some exploring on your own to find out what is really there. I myself find the second approach to be much more interesting, so I would love to hear from someone who has observed this system to know what stars are really there.

It saddens me to know that this age of exploration that we live in now with respect to double stars is about to be over. The Gaia data is going to provide exact positions for these historical mysteries, and while that will make software like SkyTools much more reliable, it will also take a lot of the fun out of observing double stars.
Clear skies,
Greg

SkyTools Developer
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#9
Quote:SkyTools 3 asks for longitudes measured to the west, which means that they are positive in the western hemisphere and negative in Europe. So it is a negative number.
Thank you for the explanation - I got it now.



Quote:There are two ways to look at double star catalog errors. You can get upset that the data isn't perfect and tell me I should fix it, or you can see it as an opportunity to do some exploring on your own to find out what is really there. I myself find the second approach to be much more interesting, so I would love to hear from someone who has observed this system to know what stars are really there.
I will try to provide you some input, but unfortunately my scopes have small aperture. But during autumn time frame 31 Cyg will be high in the sky so maybe i will be able to make a nice sketch.
In October I will try to book the scope that is available in Gdansk (http://obserwatorium.gfo.pl/o-nas/wyposazenie/), maybe despite light pollution I will be able to see more.
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