Posted 09 November 2012 - 12:56 PM
It was a nice clean split at 163x (12mm UO Ortho 1.6x Barlow), and better split and the "figure 8" diffraction rings at 320x (6mm TMB II) were quite pretty. Both splits showed a clear thin dark line.
Nice double, really. Reminds me much like a smaller Porrima - a couple of headlights way off in the distance. Both seemed pretty much white and close to the same magnitude. Looks to be a good test for 4-6" scopes in good seeing. Not sure of the actual separation, but it's getting close to that of a 6" scope. Maybe a sketch tomorrow.
Posted 09 November 2012 - 03:41 PM
Posted 09 November 2012 - 10:19 PM
Posted 10 November 2012 - 05:56 AM
Posted 10 November 2012 - 07:04 AM
I enjoy 52 Orionis... When Orion is visible, I start with Rigel, go to Zeta, then Nu and finally 52. I have read some comments that 52 Orionis might be a bit wider than than the 1.0 arc-seconds reported by WDS/Sky Tools...
Posted 10 November 2012 - 07:29 AM
Okay, gonna hit the others you mentioned tonight, too. I am new to double star observing, a lot of exploring ahead.
Posted 11 November 2012 - 01:35 PM
Posted 11 November 2012 - 06:38 PM
Great sketch, by the way!
Posted 15 November 2012 - 09:49 PM
Anyone know why it's called '52' Orionis'?
Posted 15 November 2012 - 11:53 PM
At anyrate it should be doable. Poor seeing where stars refuse to come to focus could make this problematic to impossible.
Posted 16 November 2012 - 02:43 AM
Posted 17 November 2012 - 08:14 PM
Nice double, really. Reminds me much like a smaller Porrima - a couple of headlights way off in the distance. Both seemed pretty much white and close to the same magnitude.
I tried this one last night along with some others and I had the same impression as you, a smaller Porrima. I have never observed this double, thanks for pointing it out.
The seeing was very good for a change, about 4/6 most of the time. My best view was at 300X with a 4mm ortho. Very pretty double! A clean split in the 10" dob with a thin black space separating the two equal components.
Posted 24 November 2012 - 01:57 PM
52 Ori is the top gem in a list of six double/ multiple stars in Orion ,described by Norman Lockyer in his book ,,Stargazing-Past and Present'' published at Macmillan and Co., London, 1878.
I first passed through this sequence with my 125mm F/7 Dobsonian in 2010,right before Christmas:freezing cold,deep snow ,ocasional wind gust, it took me three and half hours to complete the sequence.
I was successful at splitting the first five double/multiple stars but failed on 52 Ori.
Only at the third sequence attempt I was able to split 52 Ori.
Knowing what to expect and where to look,last week I passed through the Lockyer sequence with success in about ten minutes with the same telescope.This time,I splitted 52 Ori at 144x/6mm Radian eyepiece.
I found this Lockyer sequence inspirational and very entertaining:quaint old Kitchener,Admiral Smith and Sir John Herschel were claping my shoulders ,encouraging me to continue,to go till the end.Which I did:52 Ori is one of my Winter trophee,but not all the time!
And I knew from an authoritative source like Norman Lockyer itsef that my telescope ''is by no means to be despised''!
I have an article about the Lockyer Sequence on my blog:
Here is a link to download from ,,archive.org'' the whole book ''Stargazing-Past and Present'' by Norman Lockyer:
Quotes from ‘’STARGAZING: PAST AND PRESENT’’ by J.Norman Lockyer
London. MACMILLAN AND CO. 1878
Book II,CHAP. XII,page 164-166
‘’The convenient altitude at which Orion culminates in
these latitudes renders it particularly eligible for observation
; and during the first months of the year our
readers who would test their telescopes will do well not
to lose the opportunity of trying the progressively
difficult tests, both of illuminating and separating power,
afforded by its various double and multiple systems,
which are collected together in such a circumscribed
region of the heavens that no extensive movement of
their instruments an important point in extreme cases
will be necessary.
Beginning with DELTA, the upper of the three stars which
form the belt, the two components will be visible in
almost any instrument which may be used for seeing
them, being of the second and seventh magnitudes, and
The companion to BETA though of the same
magnitude as that to DELTA , is much more difficult to observe,
in consequence of its proximity to its bright primary,
a first-magnitude star. Quaint old Kitchener, in his
work on telescopes, mentions that the companion to
Rigel has been seen with an object-glass of 2 3/4-inch
aperture ; it should be seen, at all events, with a 3 -inch.
ZETA the bottom star in the belt, is a capital test both of
the dividing and space-penetrating power, as the two
bright stars of the second and sixth magnitudes, of
which the close double is composed, are exactly 2.5" apart,
while there is a companion to one of these components
of the twelfth magnitude about 3/4 seconds distant. The small star below, which the late Admiral Smyth, in his charming book," The Celestial Cycle," mentions as a test for his object-glass of 5*9 inches in diameter, is now plainly to be seen in a 3 3/4 inch. The colours of this pair have been variously stated ; Struve dubbing the sixth magnitude which, by the way, was missed altogether by Sir John Herschel "olivaceasubrubicunda."
That either our modern opticians contrive to admit
more light by means of a superior polish imparted to the
surfaces of the object-glass, or that the stars themselves
are becoming brighter, is again evidenced by the point of
light preceding one of the brightest stars in the system composing SIGMA . This little twinkler is now always to be seen in a 3 3/4-inch, while the same authority we have before quoted -Admiral Smyth -speaks of it as being of very difficult vision in his instrument of much larger dimensions. In this very beautiful compound system there are no less than seven principal stars ; and there are several other faint ones in the field.
The upper veryfaint companion of LAMBDA is a delicate test for a 3 3/4-inch,
which aperture, however, will readily divide the closer
double of the principal stars which are about 5" apart.
These objects, with the exception of ZETA, have been given
more to test the space-penetrating than the dividing
power ; the telescope's action on 52 Orionis will at once
decide this latter quality. This star, just visible to the
naked eye on a fine night, to the right of a line joining
ALPHA and DELTA, is a very close double. The components, of the
sixth magnitude, are separated by less than two seconds
of arc, and the glass which shows a good wide black
division between them, free from all stray light, the
spurious disk being perfectly round, and not too large,
is by no means to be despised.
Posted 24 November 2012 - 02:23 PM
Thanks for the link to that book. There's a fabulous picture of someone (Mayall?) sitting at the eyepiece end of a huge refractor -- no idea where that was taken, but you can almost hear the creaking of machinery and smell the cold air in the dome. It's page 11 using the page numbers of the .pdf format.
Posted 24 November 2012 - 04:00 PM
Posted 24 November 2012 - 09:31 PM
Because it's bright, as well as close, air steadiness appears to affect resolving it more than some. I've found I need different magnifications on the same telescope on different nights for this one, depending on the seeing. It's a fine pair when you get a steady view.
Posted 24 November 2012 - 10:08 PM
Posted 25 November 2012 - 12:34 AM
If you search for something, you're probably better off to use the search window instead of the Select Category window. Wordpress has made a change in the way those constellation selections come up which doesn't work as well as it used to.
Posted 25 November 2012 - 03:57 PM
I'm glad you are enjoing the book,this is the kind of stuff I like.
The trophee of today is the booklet ''Hints on Reflecting and Refracting Telescopes'' By Horne Thornthwaite,London,1880 ,downloaded from archive.org.
I agree with you.There were apparently quiet nights when not even 236x was able to split 52 Ori.It was the first time to split 52 Ori at 144x.
One thing I intend to do is to dig and find where Kitchener ,Admiral Smith and John Herschel made that statements.
It will be not easy,I had read the book on telescopes of ''old quaint'' Kitchener and don't remember the quote about Rigel.But there are so many informations packed in that small lovely book and being age 58 I noticed my memory is no more what used to be (or at least my wife say so)!
Clear sky to all of you,now I'm going under the stars to try my luck with Eta Ori and 32 Ori.
Posted 25 November 2012 - 04:38 PM
Scope used was 150mm f/8 refractor and aperture mask.
Posted 26 November 2012 - 02:09 PM
Posted 27 November 2012 - 02:21 PM
Did you ever use aperture masks to determine the aperture limit for splitting doubles?
My sketches of this pair from a couple of years ago.
Scope used was 150mm f/8 refractor and aperture mask.