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Session plans for Equ

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#1 WRAK

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Posted 30 September 2013 - 08:26 AM

I hope for at least one or two clear nights in October to be able to do the following planned sessions in Equ:

Equ Route 1
01.01 Gam Equ (KNT5, HIP 104521) – 1"DS +4.70/8.69mag. 210mm pA. Separation 1.13" according to Bill? pA then 190mm.
01.02 STF2765 (HIP 104570) – 2.8"DS +8.47/8.50mag. 63mm pA.
01.03 BU1501 – 1.1"DS +10.96/11.27mag. 181mm pA.
01.04 Del Equ (STF2777, HIP 104858) – 74.3"DS +4.54/10.17mag. 34mm pA.
01.05 HJ3019 – 15.1"DS +10.05/11.73mag. 93mm pA.
01.06 HJ3020 – 25.8"DS +11.28/11.39mag. 82mm pA.
01.07 HJ3021 – 23.7"DS +11.38/11.89mag. 94mm pA.
01.08 STF2786 (HIP 105295) – 2.8"DS +7.49/8.2mag. 61mm pA.
01.09 STF2793 (HIP 105747) – 26.7"DS +7.44/8.98mag. 29mm pA.
01.10 HJ933 – 17"DS +10.16/11.91mag. 96mm pA.
01.11 BU163 (HIP 105200) – 0.9"DS +7.31/8.88mag. 156mm pA. Orbit.
01.12 A887 (HIP 105784) – 11.9"DS +8.29/11.70mag. 99mm pA.

Equ Route 2
02.00 Alpha Equ (HIP 104987) +3,94mag. Starting Point.
02.01 BU682 (HIP 104860) – 5.5"DS +7.69/12.2mag. 146mm pA.
02.02 J1721 – 3.8"DS +9.6/12.5mag. 149mm pA. UCAC4 shows only +11.065mag single star.
02.03 BU838 (HIP 105399) – 1.6"DS +7.92/10.02mag. 124mm pA.
02.04 STF2791 (HIP 105634) – 2.8"DS +8.92/9.28mag. 70mm pA.
02.05 J2341 – 7.3"DS + 9.5/9.9mag. 61mm pA. UCAC4 shows +11.859/11.859mag. pA then 104mm.
02.06 BU270 (HIP 104767) – 0.6"DS +7.42/9.4mag. 241mm pA. Orbit.
02.07 STT428 (HIP 104399) – 24.1"DS +8.41/9.93mag. 47mm pA.
02.08 BU269 (HIP 104028) – 1.1"DS +8.34/10.07mag. 155mm pA.
02.09 STF2742 (HIP 103813) – 2.9"DS +7.41/7.64mag. 58mm pA.
02.10 BUP224 (HIP 104101) – 30.7"DS +5.94/12.4mag. 99mm pA.
02.11 A615 – 3.4"DS +9/12mag. 140mm pA. UCAC4 shows +9.772/11.116mag. pA then 105mm.
02.12 AG268 – 12.3"DS +8.59/9.99mag. 54mm pA.
02.13 Eps Equ (STF2737 AB, HIP 103569) – 0.4"DS +5.96/6.31mag. 290mm pA. Orbit.
02.13-1 STF2737 AC (HIP 103571) – 10.6"DS +5.3/7.05mag. 15mm pA.
02.13-2 STF2737 AD – 78.6"DS +5.96/13.1mag. 124mm pA.
02.14 STF2749 (HIP 104047) – 3.2"DS +8.06/9.36mag. 67mm pA.

Both sessions have a sequence with less than 3° hops from one target to the next.
Several objects have questionable entries in the WDS catalog, UCAC4 magnitudes are given with the use of Tom's website.
"Orbit" indicates an entry in the 6th orbit catalog.
pA means proposed aperture according to my current RoT algorithm (with zero CO and some light pollution) and is given to check the validity of this algorithm.
May be these session plans are also of interest for other observers - any observation reports would be appreciated.
Wilfried

#2 fred1871

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Posted 01 October 2013 - 09:48 PM

Interestingly varied lists, Wilfried - the telescope diaphragm will get quite a workout.

One of your listed pairs will certainly, if the calculated orbit is accurate, be more difficult than expected. Epsilon Equ is a 101.5 year binary, at present closing, and the 6th Orbit Catalog ephemeris (interpolating)gives 0.32" for 2013.75, with 0.305" by 2014.0, and 0.248" by 2015.0, so it will be even harder next year.

#3 azure1961p

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Posted 01 October 2013 - 11:53 PM

Fred,
Sky Safari lists the magnitudes for Epsilon Equ as 5.4-7.3 with 0.3" . I don't have the info on exactly which cat they got it from but there you go. Based on my recent experiences with Delta Equ that had similar seperation but closer magnitudes Id really think something like a 10 or 11" aperture might be minimum to see an elongation - IF - my magnitudes are correct. I couldn't imagine a mag difference like that not making the job a lot harder.

Wil,

A discrepancy between Sky Safari and your source is SS doesn't recognize STF2777 at all and what is shown for your HIP 104858 is in fact Delta Equulei with the 0.3" seperation and mags 4.5-4.69. Now there IS a mag 10 star nearby : TYC 1109-2584-1 but its not listed as related in anyway.
I know what the WDS shows but they aren't always correct for example 325.95" sep listed for Delta EQ.


Just passing it along.



Pete

#4 fred1871

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Posted 02 October 2013 - 12:36 AM

Ummm... Sky Safari does it again - unhelpfully?

Epsilon Equ (STF 2737) has magnitudes of 5.96 and 6.31 listed in the current WDS. Same as Wilfried gave. The figure I quoted for separation was from the 6th Orbit Catalog. I prefer the standard sources. Yes, if the SS mags were true it'd be even harder to split; but I'd only go with SS ahead of WDS if I had a big enough scope to split this one and found by observation that the pair was nearly 2 mags unequal, instead of nearly equal. Or if there was some new photometry suggesting Tycho (basis here for WDS) got it wrong.

Concerning STF 2777 - here are the data lines from WDS:
21145+1000STT 535AB 1852 2013 523 15 18 0.4 0.3 5.19 5.52 F6V F6V +040-304 +09 4746 NOD 211428.81+100025.1
21145+1000STF2777AB,C 1781 2011 90 78 6 19.5 74.3 4.54 10.17 F6V F6V +040-304 NL 211428.81+100025.1

STF 2777 is the very wide pairing of mags 4.5 and 10.2; the very close binary is the 'A' star here, mag 4.5, which has the designation STT 535AB - mags 5.19 and 5.52 in the current WDS, with a 2013 measure of 0.3" at 18d PA. And, yes, it is Delta Equ. And the WDS notes identify the wide 10th mag component as "optical".

So SS doesn't recognise STF 2777 at all? - it might only mean it doesn't include super-wide pairs.

A point to note is that some multiple stars have more than one discoverer designation, specific in each case to who discovered which component.

#5 WRAK

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Posted 02 October 2013 - 02:19 AM

It seems impossible to make a list of doubles for any region without getting some questionable objects - one of the reasons why double star observing is this interesting.
Doubles with separations below 0.5" separation are included in my lists only as hops - I have no reason to expect resolution here with 140mm, not even elongations.
The wider pairs are also included mostly as hops but if the companion is fainter then also as check for the RoT TML module.
I am still waiting for a clear night and have meanwhile prepared star maps for manual navigation with horizontal flip and Alt/Az rotation for mid October with location central Europe but this maps may be of use also in other locations in the northern hemisphere. Hopefully a clear night will come before mid October as then the Moon is coming again.
But for the entry points I have to use DSC anyway as light pollution is with NEML +3.5mag or worse too heavy in my location to locate Gam Equ and Alpha Equ directly.
Wilfried

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#6 WRAK

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Posted 02 October 2013 - 02:20 AM

Maps for Equ Route 2. Wilfried

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#7 azure1961p

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Posted 02 October 2013 - 08:04 AM

Wil,

Yes discrepencies in information seem quite common and it certainly adds a discovery sense to things in ferreting out the truer nature at the scope. Edz had mentioned his interest in uncovering these when they'd rear their head in his observing.j

Fred, I try not to beat up on SS as it does so many things astonishingly well - and at a fair price . My feelings on SS not mentioning STF2777 is that the app may infact ignore optical doubles? It mainly states however that it is not in the app data base when I search for it. My wisdom at this point on doubles and SS is trust but verify. On the whole its effective but it needs confirming. Its an EXCELLENT star hopping tool at the scope with my dob. I suppose with my c6 I can just hop it with GOTO - it'd pack more doubles in for an evenings effort. Lol, I think I just myself into taking it out next doubles session!

Pete

#8 WRAK

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Posted 03 October 2013 - 05:04 AM

Unexpected clear sky at midnight, NRML ~3.5, SQM ~18, Pickering ~6. Equ already a bit low in altitude (below 40°) but I had to try fast forward Equ Route 1 with 140mm:
01.01 Gam Equ (KNT5, HIP 104521) – 1"DS +4.70/8.69mag. 210mm pA. Separation 1.13" according to Bill? pA then 190mm. Negative with 140mm
01.02 STF2765 (HIP 104570) – 2.8"DS +8.47/8.50mag. 63mm pA. x40 Rod at 1 o'clock. x75 split at 1:30. x200 limit aperture 60mm. Experiment with CO mask - see separate post
01.03 BU1501 – 1.1"DS +10.96/11.27mag. 181mm pA. x280 Rod at 6 o'clock? Should have been 7. Best case lucky hit, no resolution
01.04 Del Equ (STF2777, HIP 104858) – 74.3"DS +4.54/10.17mag. 34mm pA. x40 very faint at 11 o'clock
01.05 HJ3019 – 15.1"DS +10.05/11.73mag. 93mm pA. Skipped
01.06 HJ3020 – 25.8"DS +11.28/11.39mag. 82mm pA. Skipped
01.07 HJ3021 – 23.7"DS +11.38/11.89mag. 94mm pA. Skipped
01.08 STF2786 (HIP 105295) – 2.8"DS +7.49/8.2mag. 61mm pA. x40 elongation 5 o'clock. x75 split. x140 limit aperture 60mm. Experiment with CO mask - see separate post
01.09 STF2793 (HIP 105747) – 26.7"DS +7.44/8.98mag. 29mm pA. Skipped
01.10 HJ933 – 17"DS +10.16/11.91mag. 96mm pA. Skipped
01.11 BU163 (HIP 105200) – 0.9"DS +7.31/8.88mag. 156mm pA. Orbit. x200 elongation 7 o'clock? x280 no change. Correct position 7:30 – with current seeing and low altitude rather lucky hit, but with better seeing and higher altitude certainly to resolve with 140mm. Another experiment with CO mask - see separate post in thread "How good are reflectors for resolving binaries?"
01.12 A887 (HIP 105784) – 11.9"DS +8.29/11.70mag. 99mm pA. Skipped.

Wilfried






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