Wrong information in sky safari pro?

[Stu]

The position looks wrong to me. It looks like it is at 0.6" separation, not 14", so the measurement is right, position is wrong.

[Paul73]

Be fair chaps. We are talking a massive data set here! But, as you point out, they can’t make it right if they don’t know that it is wrong.

@cotterless45 - Nick - in your view, what is the most reliable source of double/multiple star data? 

Paul

PS. In SS 5 Pro Sigma Orionis is wrong too ?. 

[Analysis Paralysis]

40 minutes ago, Grogfish said:

Just a small point, and I don't think more proof is needed that something's wrong, but: 0.6" with the quoted 31.1AU seperation corresponds to 169 light years, roughly twice the currently accepted distance to  Mizar, which ain't right!

Did you calculate that yourself? If so, how did you do it, as I am interested. All versions show correct distance. Also, I opened version 4 on iPad and checked the position against version 5 on my android. I could clearly see a difference in the position numbers, but also very clearly the picture looked different. At this time i.e. "now", Mizar B would be nearly due 'west' of A according to version 4, but south-west according to version 5  and 6. Unfortunately I can't check this yet, because I have a scope but not a mount! Any chance you could visually check which position is correct at some point ? My money will be whatever version 4 is saying. But, to conclude, I think your theory is correct about the separation error being linked to incorrect positional data for the two stars.

Mark

[Analysis Paralysis]

1 hour ago, Stu said:

The position looks wrong to me. It looks like it is at 0.6" separation, not 14", so the measurement is right, position is wrong.

Yes, it looks like incorrect positions is behind the problem. 

[Analysis Paralysis]

1 hour ago, Paul73 said:

Be fair chaps. We are talking a massive data set here! But, as you point out, they can’t make it right if they don’t know that it is wrong.

@cotterless45 - Nick - in your view, what is the most reliable source of double/multiple star data? 

Paul

PS. In SS 5 Pro Sigma Orionis is wrong too ?. 

Hi Paul, you are right. And ultimately our intention is to help improve the app information, not to criticize the developers ?. If they don't know there is an issue they can't correct it. Interestingly, it has been pointed out by another poster that SS PRO 4 showed correct position and separation...

[chiltonstar]

I've found a few errors in SS, some of which were just old data - fairly inevitable with such a large dataset as is stated above.

Stelle Doppie/WDS seems to be regarded by many as the most reliable data source - I check all SS data against these  and CDSA which is generally pretty good,

Chris

[cotterless45]

I'll go along with that . It's quite interesting to look up older sources and see how not only how some separations have changed , but also RA and Dec. It's even more interesting to see how magnitudes are variously reported as well colours,

Nick.

[Analysis Paralysis]

1 hour ago, cotterless45 said:

I'll go along with that . It's quite interesting to look up older sources and see how not only how some separations have changed , but also RA and Dec. It's even more interesting to see how magnitudes are variously reported as well colours,

Nick.

Hi Nick, as the OP for this, would you recommend use of the Simbad portal. I found it showed 14.4" as Mizar A and B separation. This thread started because I posted a query asking if members agreed 0.6" was not correct, as stated in SS PRO 5 and 6, but apparently not in 4, which has 14.4". We have concluded that the source of the separation error is due to incorrect positions for these two stars that has somehow crept into the version 5 then carried into 6. Stu has contacted the support forum to ask them. 

Cheers

Mark

[Ouroboros]

Who produces the database I wonder? If this is the source of an error it may well go further back than SkySafari who presumably just 'buy in' the data base. 

[Analysis Paralysis]

11 minutes ago, Ouroboros said:

Who produces the database I wonder? If this is the source of an error it may well go further back than SkySafari who presumably just 'buy in' the data base. 

Yes.. hopefully ss can shed light on this

[Stu]

No answer as yet, I think they have their hands full 'snagging' the new version, will keep you posted.

One interesting thing I found out relates to the measurement tool. I thought the new way was quite cumbersome, but having made a measurement, you can then drag and drop to other objects and measure from the original object. Works very well.

[Stu]

Have had a response and they have acknowledged that there is a error there which wasn't in 4. They will look into it and resolve when they can/know how to.

[Analysis Paralysis]

53 minutes ago, Stu said:

Have had a response and they have acknowledged that there is a error there which wasn't in 4. They will look into it and resolve when they can/know how to.

Excellent! Thank you Stu!

Job well done. And also, most importantly, confirms I wasn't going mad (yet). I wonder if this can be cured with an update to SS6 or will we have to wait for SS7, which will be quite a wait, I suspect. 

Mark

[Scooot]

4 hours ago, Analysis Paralysis said:

Excellent! Thank you Stu!

Job well done. And also, most importantly, confirms I wasn't going mad (yet). I wonder if this can be cured with an update to SS6 or will we have to wait for SS7, which will be quite a wait, I suspect. 

Mark

I think they’ll update ss6 because it’s incorrect information and not everyone buys the new versions. I wonder if there are other errors caused by the same bug that haven’t been discovered yet. 

[Analysis Paralysis]

36 minutes ago, Scooot said:

I think they’ll update ss6 because it’s incorrect information and not everyone buys the new versions. I wonder if there are other errors caused by the same bug that haven’t been discovered yet. 

Yes, I'm not an expert in these matters, but I know I have many apps which are always updating without being a new version.