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Helping out the pros again

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lunator

lunator

Posted
Posted

I have continued my investigation into some of the nelected doubles in the WDS.

One of the easier pairs I found was HL 30AB. A bright wide triple in the Pleaides.

The Cartes Du Ceil had several bright pairs in this area and as it is a star cluster I thought this could be plausible.

I spent quite a bit of time searching the area and could only find one triple that was a fit for the measurements.

I measured them using the Microguide.

To verify my search I took an afocal image of the area using the fuji camera as this will get stars down to Mag 11 and again I could only see one pair that matched the WDS data. I also downladed an image from Aladin which confirmed one triple not 2.

I have attached the images below.

I sent Dr Brian Mason & Bob Argyle the following email

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Hi Brian & Bob,

I hope you had a good Christmas & New Year break. I wanted to highlight a query I have on the neglected double HL 30AB.

I had this on my list of targets last night and found a pair that closely matched the description of PA 16 Sep 66.2". My measurements were PA 14.5 and separation of 66.3".

The primary component for this pair is the secondary of the STTA 40 pair.

On my Cartes du Ceil software that contains the 2004 WDS there was another star very close too the HL 30AB co-ordinates and of a similar PA, separation and magnitude. This pair is noted as STU 2BC.

I Also noticed that the HL 30AC and STU 2BD were very similar. The information from the 2006.5 WDS is set out below.

03493+2424HL 30AB 1886 1886 1 16 16 66.2 66.2 7.53 10. +23 560 N 034916.8 +242346.

03494+2423STU 2BC 1986 1986 1 13 13 66.5 66.5 7.53 10.6 +019-044 034916.8 +242345.

03493+2424HL 30AC 1886 2000 4 240 242 83.4 81.1 7.53 10. D 034916.8 +242346.

03494+2423STU 2BD 1986 1986 1 240 240 80.3 80.3 7.53 10.7 034917.9 +242450.

To try and record what I observed I took an Afocal image using my digital camera and had annotated the image using the data within CduC. I have attached the bitmap image. I have also included the 1 degree field from CduC as a comparison and an inverted image of STTA 40 from Simbad/Aladin.

I have come to the conclusion that HL 30AB and STU 2BC are the same pair, and HL 30 AB and STU 2BD are also the same pair.

I was unable to find LDS6116.

Regards & Happy New Year

Ian

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

I got a reply today :p

Ian,

Excellent analysis!

Brian

--------------------------------------------------------------------------------------------------------------------------------------------

One more case solved by the DSD (double Star Detective :D)

A more formal write up will be in the DSSC15 from the Webb Society.

Cheers

Ian

These are the images.

<img src=http://iseestars.net/image/7144/large/image.jpg alt=ISEE STARS Image>

<img src=http://iseestars.net/image/7140/large/image.jpg alt=ISEE STARS Image>

<img src=http://iseestars.net/image/7143/large/image.jpg alt=ISEE STARS Image>

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Ant

Ant

Posted
Posted

Please excuse my ignorance Ian.

Whilst I don;t really understand what your message implies.

Does this mean that there are two doubles that should actually have been only one? and from your observations they are going to change the official records?

If I've got it completely wrong you still seem to be doing rather well - just someone needs to tell me on what :D

Cheers

Ant

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lunator

lunator

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Posted

Please excuse my ignorance Ian.

Whilst I don;t really understand what your message implies.

Does this mean that there are two doubles that should actually have been only one? and from your observations they are going to change the official records?

If I've got it completely wrong you still seem to be doing rather well - just someone needs to tell me on what :D

Cheers

Ant

Ant yes you have understood it perfectly :p

Looking at the notes on the WDS data.

This pair was first observed by A Hall in 1886.

The same pair was observed by K Sturdy in 1986 but due to proper motion and precession the co-ordinates had changed slightly so it was added as a separate pair.

There are examples were you can have 2 pairs almost identical and very close to each other. An example is STI2471 & STI9001. They are within 144 arc seconds of each other and are almost identical but they are most definately separate pairs.

The only way to check is to look :p

Cheers

Ian

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lunator

lunator

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Phil

A knight of the Realm? do they still sell armour? not sure I can afford a horse it would seriuosly dent my (small) astro budget.

I found out last night as I was reading Patrick Moores book on Mars that Asaph Hall was the discoverer of Phobos & Deimos in 1877.

He was a well known observer using the 26 inch refractor in Washington.

Cheers

Ian

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Kaptain Klevtsov

Kaptain Klevtsov

Posted
Posted

I found out last night as I was reading Patrick Moores book on Mars that Asaph Hall was the discoverer of Phobos & Deimos in 1877.

He was a well known observer using the 26 inch refractor in Washington.

Ian, that's really impressive and I'm really impressed. You have changed real, proper, official, tablets of stone stuff there mate. How good is that?

Now I need to get my own 26 inch APO and we're away. And why would you need a 26" Frac. in 1877? Light pollution or what? Surely he would have had a dark sky everywhere? Stick the DSLR on and voila. I suppose he never thought to try that.

Captain Chaos

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lunator

lunator

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Posted

I nailed another one last night.

J 252. A neglected pair in Taurus.

It was last observed in 1955 & the observer an amateur called Jonckheere who found it originally used a 33cm refractor!

It was listed as magnitude 9 but I found it to be abit fainter.

I used Aladin to confirm my observation and have mailed Dr Mason. & this is the reply.

-------------------------------------------------------------------------------------------------------------------------------------------------------

Ian,

Congratulations! Jonckheere neglected pairs are typically quite difficult. As an observer, I have found them considerably fainter than the quoted magnitude.

Brian

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On Fri, 2007-01-26 at 11:32 +0000, Ian Coster wrote:

>

> Hi Brian

>

> I have been investigating this neglect double over the past week. Here

> in the UK we have several clear nights in a row, which is a bit of a novelty.

>

> I initially could not find a double to match the WDS data.

>

> 05585+2723 J252 1910 1955 3 318 319 4.9 4.9 9

> 9.8

> 055825.58+272201.4

>

> There was a brief period last night when the sky transparency had

> improved enough to show a star close to the WDS co-ordinates was a

> double. It was too faint to measure using my Microguide but I sketched

> the field and would seek toconfirm the observation using Aladin.

>

> >From my analysis of Aladin I believe that J252 is a visual double

> >with the

> primary being TYC 01871 01656 1.

>

> My measurements using the Aladin plate POSSII NDSS are PA 319.6,

> Separation 4.8".

> Epoch 1998.872

>

> I have included a screenshot from Cartes du Ciel, 3 Aladin plates and

> the

> TYC2 data from Vizier.

>

> Plate one show the general field (12'9x12'9) centred on the closest

> object to the WDS co-ordinates I could fine in Aladin.

>

> Plate 2&3 are closer views of the pair.

>

> I have annotated them for clarity.

>

> As an extra note there appears to be a close visual double 50" to the

> North West of J 252. I have measured them as PA 43 Separation 2.3"

>

>

> Regards

>

> Ian

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lunator

lunator

Posted
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A further update :)

Thew Webb Society new circular is about to be published.

It will be available as a free pdf download fro the Webb Society website

http://www.webbsociety.freeserve.co.uk/

I have finally cracked another neglected double SHR 1. Measured by Schiller at the Strasbourg Observatory in 1910.

It took some working out as Schiller measured one pair and put the co-ordinates in for a different but close by pair.

The main issue was I observed 2 pairs one at the right co-ordinates and one with the correct structure.

I now have a new 'law'. If the stars are not in the right place it is due too human erro not stellar error :)

As a point of interest these measurements were taken when Strasbourg was part of Germany.

Below is the mail from Brian Mason.

Cheers

ian

-------------------------------------------------------------------------------------------------

That looks like the right conclusion to me.

Brian

On Thu, 2007-03-15 at 21:19 +0000, Ian Coster wrote:

> Hi Brian

>

> I have been investigating this neglected pair and would like to share

> what I have found.

>

> Bob has been helping me with this investigation and I have written a

> piece for the DSSC15.

>

> Whilst finding this pair I found 2 pairs that could be SHR 1.

> One pair is a good fit with PA/Sep & magnitudes.

> The other pair is at the correct co-ordinates (taking precession into

> account).

>

>

> Both pairs show slight proper motion but not enough to explain the

> difference in co-ordinates.

>

> As I said in the mail below to Bob I am coming to the conclusion that

> Schiller measured the 1st pair but put the co-ordinates down for the

> 2nd pair.

>

> I would like to hear what you think.

>

> Many Thanks

>

> Ian

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