Eugene(Bombardon) and myself(bigjoe) have come up with the idea of a Monthly Constellation Doubles observing report.
We'll tommorrow post the Doubles selected in the Constellation to be observed for that month...giving you plenty of time to observe and report due to weather.
We though we'd choose 6 of the many doubles in ORION to kick it off.
Suggestions for these Monthly Constellation doubles reports, selections etc are also welcome ..esp from Tinderboxsky(Steve) Mekon(John) , Steffen etc.
Though nothing too technical, such as stating position angles as mandatory...as this is for the uninitiated also.....So how to best go about it..PICK some say MAX of 6 Doubles per Constellation..and not always the obvious ones .
This will be for anyone interested in Starsplitting as part of their observing regime...Novice or Veteran.
Even if your not an avid doubles observer, we would like to hear of your observation .....even if you only get time to observe just one of those selected in your humble 60mm Tasco, let us know!
Resolution limits for your aperture, use either...
The DAWES LIMIT for YOUR scope ..116/Diameter in mm..barely will you see a hairline split.
RAYLEIGHS LIMIT 138/D mm a clear dark line will separate them in comparison.
These LIMITS ALL are based on components of equal magnitude; in practise most doubles are NOT Equal, and tougher.
Tell us about how HARD or EASY it was in your scope, at its RESOLUTION LIMIT e.g. Say 1.1 " in a 4 inch, in as good as seeing as you can..don't worry too much about transperancy..its really the seeing thats important... WHAT WHERE THE ...
Stars selected and observed..state their mags and separations when reporting.
Scope and Eyepiece(s) used .
Magnification(s) used.
Colour Contrasts seen .
SEEING ,Transperancy at the time.
LOCATION, Time, Altitude above horizon(can estimate).
Separation will be given, but is it as stated?.. this for the experienced ones.
PA... Is PA stated accurate..though this is NOT necessary, only for the expert .
Type of doubles observations....you'll need very good seeing at least for the first three.
1: Was it a figure eight..unsplit
2: Kissing and unsplit
3: A hairline split = split
4: Or best, a solid split .
Some doubles will be tough, some easy...the point is to have a go at some, and have fun testing your optics at the same time!
And remember no matter how inexpensive your scope, how cheap your Plossls, Kellners are ...we'd like to hear from you...NO Elitism or bagging scopes welcome .
Remember also SMALLER instruments produce LARGER AIRY DISKS at high magnifications, and can actually be BETTER in poorer seeing than LARGER instruments.. this Airy Disk size, or Diffraction Limit for aperture is inversely proportional to the increasing aperture.
Larger scopes...... some with central obstructions, and their resulting SMALLER Airy Disks, bright diffraction rings or spikes can obscure a faint secondary, long cooldowns, thermal currents crossing mirrors, heat plumes off baffles etc... these need more time to cool down.
Try to use 1 eps as a Standard eyepiece IF you want to judge separations..though this is NOT NECESSARY here, VIZ....
Know what say 10" arc looks like in your go to eyepieces for example as in Rigel.
Formula for this..... OCULAR FIELD STOP in mm X 57.3 / FOCAL LENGTH OF SCOPE IN mm.
EG: EP Has field stop* 3 mm, scope 1719 mm focal length
Then thats .. ( 3 x 57.3 )÷ 1719 = 1/10 degree true field of view or 6 mins of arc or 360" IN YOUR EP....So if a Double has a sep of 36" it will be one tenth of the field width of YOUR STANDARD EP, so you'll get an idea of separations and were the secondary will be in your scope!
You really only need a few EPS for this, a locator widefield , Zoom or some higher powers, and optionally a Standard EP for judging separations...all with a Flat Field.
PS: Remember also ...
MOST SCOPES ABOVE 4" ARE SEEING LIMITED AND NOT DIFFRACTION LIMITED most nights of the year...So be patient get a nice comfy chair, and wait for that moment of good seeing ...it will come...you have a month to report!
bigjoe.
Last edited by bigjoe; 23-02-2018 at 06:48 PM.
Reason: Add
Seriously though, that's a great idea, I hope you get some decent interest.
Math does my head in so I really liked what you said with hair split, figure 8 etc.
The Astronomy 2018 book has a section for double stars also, I think each month.
For the more experienced observer, here's a challenge, if I may throw one your way?
Sirrius in Canis Major is good viewing at the moment. Split its white dwarf companion. This is easier to do in the evening before the sky gets too dark as Sirrius won't appear so bright, overpowering the dim dwarf. I've been successful at getting it using 120x mag (10mm ep) with a 10" scope.
Seriously though, that's a great idea, I hope you get some decent interest.
Math does my head in so I really liked what you said with hair split, figure 8 etc.
The Astronomy 2018 book has a section for double stars also, I think each month.
For the more experienced observer, here's a challenge, if I may throw one your way?
Sirrius in Canis Major is good viewing at the moment. Split its white dwarf companion. This is easier to do in the evening before the sky gets too dark as Sirrius won't appear so bright, overpowering the dim dwarf. I've been successful at getting it using 120x mag (10mm ep) with a 10" scope.
Nice to hear from you Suzy...
Yes indeed Sirius; that should be the next one we do with Canis Major..then Gemini perhaps..
Sorry about the arithmetic Suzy... believe me theres much worse I could have included..
Hope you might have a shot at one we will include in tomorrows list ..everyone who wants gets a month to do so.
Cheers bigjoe.
Last edited by bigjoe; 23-02-2018 at 08:30 PM.
Reason: Add
Hi Big Joe
I doubt my scopes are useful but I would love to have a go...if possible.
I have a 80 mm which is maybe too small I guess, an eight inch newt and a 150 ed refractor ...I am not sure if I still have a 12 inch it may be gone.
Am I under equiped?
Also the though popped into my head and I suppose its been done but do you know if any one has taken photo over time and made a little movie like the recent one of our closest star which was over five years from memory.
Alex
Hi Big Joe
I doubt my scopes are useful but I would love to have a go...if possible.
I have a 80 mm which is maybe too small I guess, an eight inch newt and a 150 ed refractor ...I am not sure if I still have a 12 inch it may be gone.
Am I under equiped?
Also the though popped into my head and I suppose its been done but do you know if any one has taken photo over time and made a little movie like the recent one of our closest star which was over five years from memory.
Alex
Yes Alex . What a GREAT IDEA...some pics through your and others scopes would be great with these reports ..most of the doubles selected would actually be viewable in your 80mm at 1.7" diffraction limit...and high diffraction power...one or two would need your excellent 6" Refractor for sure..will be posting a list for Orion morrow..and my attempts at some..Respect always.
bigjoe.
Last edited by bigjoe; 23-02-2018 at 11:23 PM.
Reason: Adding
What was proposing was to take shots over a period of months or maybe years so strung together you may see a particulat double orbiting via an animation.
Alex
What was proposing was to take shots over a period of months or maybe years so strung together you may see a particulat double orbiting via an animation.
Alex
.
. Even better than just taking a shot...Yes why not I say...some have very slow orbits some quite rapid in only a few years..They use Keplers Laws from the PA and sep of stars over time to help calculate their Period, Masses, distance..etc .another great idea.
bigjoe.
Last edited by bigjoe; 24-02-2018 at 12:03 AM.
Reason: Adding
What Alex is getting at, is that for example, orbits like at the bottom of this web page http://stelledoppie.goaction.it/inde...iddoppia=60453
can be photographed or observed over time..thats how they calculate their Period,Masses ,distances between .... use the wonderful Stelledoppie website you'll see all info ,orbits etc
bigjoe.
Last edited by bigjoe; 24-02-2018 at 01:40 AM.
Reason: Adding
Well done Joe and Eugene for taking the initiative. I'll be a participant and contributor.
Looking forward to your first list. I like the way John has ordered his suggested list with each successive target getting more difficult.
Of course it is raining here!
I would suggest that U simply pick out a constellation or more each month n title it: Doubles in (Constellaton) and that way it would be more easly found than say: Doubles for February. Sorry to overstate it, if this was already the plan.
For Doubles in Orion, the doubles that immediately come to my mind are:
Rigel
Zeta
Eta
Lambda
Sigma.
Nevertheless, I will be interested in being informed of other fine double outside of my favourites.
Alex: I had the idea of tracking movement in Alpha Centauri, but only took one photo (yes, film) in the early 1990s, then gave up. Pity.
My computer is out ATM, this has been done on my mobile; so apologies in advance for any typos.
Well done Joe and Eugene for taking the initiative. I'll be a participant and contributor.
Looking forward to your first list. I like the way John has ordered his suggested list with each successive target getting more difficult.
Of course it is raining here!
Looking forward to that Steve..
Yes first month no STFs etc, really till people get the hang of it just easier ones to locate first up for the Novice who may want to try.
I would suggest that U simply pick out a constellation or more each month n title it: Doubles in (Constellaton) and that way it would be more easly found than say: Doubles for February. Sorry to overstate it, if this was already the plan.
For Doubles in Orion, the doubles that immediately come to my mind are:
Rigel
Zeta
Eta
Lambda
Sigma.
Nevertheless, I will be interested in being informed of other fine double outside of my favourites.
Alex: I had the idea of tracking movement in Alpha Centauri, but only took one photo (yes, film) in the early 1990s, then gave up. Pity.
My computer is out ATM, this has been done on my mobile; so apologies in advance for any typos.
Great selection Bob ..
Thats what well be doing ..posting a Constellation for that Month.
With ORION first up, then probably Gemini , as Castor, Propus , Wasat, 38 etc are great...with some other selections from you and Steve as well.
PS: A centauri..wow what an effort to try.
bigjoe.
Last edited by bigjoe; 24-02-2018 at 01:57 PM.
Reason: Add
Great idea Joe, if these Brisbane clouds ever clear, I'm in.
Looking forward to your report on some of those attempted Pat... how you go with them in your scopes and EPs..some will be tough some easy..its for all ..not many STFs etc will be included, to make them easier to find first up.
Hi Bob.
You would not believe I was thinking about such a project last nigh as my head was on the pillow.
Can you imagine what it would look like over time...I think it would be like an electron cloud, at least the way I imagine one.
I was thinking all about the various objects over time...
There may be globulars that have more movement than others that could be the object of such a project...but if I was younger and starting out I would be doing several...
Say you are twenty imagine the neat stuff you would have by my age...fifty years fifty projects...now theres a thread title if ever I saw one.
Alex
EIGHT Stars have been selected for this months Constellation......... ORION.
Try all, or any in your scope and EPs, and tell us what you see...ALL NOVICE AND VETERAN Astronomers welcome to have a shot.
Remember....
PA is just the position angle, no need to worry about that here.
Some Stf and Herschel stars, will be included in next months Constellation . Most selected will be readily seen, and found in the screen shots off SKYSAFARI PRO below.
This months List for ORION is....
RIGEL(Beta Orionis): Separation 9.5". Magnitude of pair AB : 0.28, 6.8.
PA 202°. What do you see?
RA 05h 15m 24s DEC -08°11' 02".
31 ORIONIS: Separation of pair is 12.8". PA 88°. Mags of pair AB: 4.7, 9.7 ...An absolute GEM...Colours seen?
RA 05h 30m 38s. DEC -01°04' 52".
RHO ORIONIS (p ): Separation 6.9". PA 62°
AB: MAGS 4.5, 8.5.. a pretty double.
RA 5h 13.1m. DEC +02° 51' 40".
SIGMA ORIONIS: (σ Orionis).... Superb.
AB Combined at Mag 3.7, is too close to separate for anyone, star C at magnitude 8.7 at a Separation of 11.6 " away from the AB pair isnt....
with two magnitude 6.6 stars, Called D and E, at separations 12.7" and 41.50" respectively from the AB pair ......so you'll actually see four coloured stars.......
What colours do you see? Lovely Struve 761 a triple also in FOV.
RA 05h 38m 45s . DEC -02° 36' 00".
ZETA ORIONIS (ALNITAK): Actually a triple! A, B, C. Near the Horsehead on the charts below, and PART OF ORIONS BELT.
PA 167°.
Magnitudes A: 1.77 , B: 3.7 , C: 9.6
Separation AB: 2.18″..... Sep to BC: 58.0"
RA 05h 41m 39s DEC -01° 56' 10"
SAIF AL JABBAH (ETA ORIONIS): PA 77°..SEPARATION 1.8"..Looks like an n on the SS charts below.
AB: Magnitudes 3.39, 4.89.
RA 04h 24m 09s DEC -02° 23' 50".
32 ORIONIS: PA 44°... Separation 1.3". Brightest star just inside Orion near Bellatrix. MAGS AB: 4.23, 5.75 .
RA 05h 30m 47s DEC +05°56' 53" .
Use DAWES LIMIT for your scope as equal enough..Sep given in Eaglecreek observatory and elsewhere is wrong..not 0 .7".
52 ORIONIS: SEPARATION 1.0" PA 220°.
Mags AB: 5.99, 6.03 ............Very, very, TOUGH, at or near 120mm aperture; needs very good seeing with aforementioned aperture...at least they are equal pairs, making it easier than otherwise using Dawes limit for your scope.
RA 05h 48m 58s DEC +06° 27' 27".
Remember were not twisting anyones arm here, were aware of many peoples Double Star Inertia....No obligation to try them all; a few sentances will do, on what you've seen, equipment used, EVEN high power Binos that some have , and magnification used will do, when you have the free time for this months Constellation, observe then post.
PS: As usual any amendments, or suggestions for next months Constellation welcome.
