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Your favorite double stars to observe

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#1 AjithSeattle

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Posted 29 June 2013 - 10:27 AM

Last night, after three patient days of waiting for a chance to get to my telescope, I found a few hours where part of the northeast and eastern night sky was clear enough to setup my scope.

While it was not technically a "first light" for my Orion XT8i, it was the first time I used the 2-star align. After my first alignment attempt with Vega as the first star and Deneb as the second star yielded a warp factor of +3.5, I tried again. Altair was still behind the trees and I live in an neighborhood with lot of street lights and one shining directly at me in close proximity in the direction of tree-obscured Altair.

For the second attempt, I chose Vega again for the first star alignment and Polaris for the second alignment and this worked out great. It yielded a warp factor of -0.3 on the object locator. After I had this setup, I looked closely at polaris for the first time. It is a double! I'm sure all of you know it was a double and a cepheid variable but I didn't last night and it pleasantly surprised me. First, I thought I was miscategorizing some other stellar entity for Polaris, so I went to a narrow FOV with 4mm Plossl and large magnification. The idea was that it would drift away from my observational view like Vega did if it is not Polaris. After 5-10 minutes of leaving the scope as it while I digged around the Stellarium for RA/Dec and Alt/Az for Polaris for my vantage point,the field didn't change, it was dead center in the field. I also have a Wixey mounted on my XT8i and it showed good alignment with altitude with the Stellarium program.

Now, I read yesterday night that Polaris is actually a triple and not a double - apparently while the faint companion seen in 8" scope is the first one discovered by Herschel in 1780, there is another fainter white dwarf that was spectroscopically identified in 1929 and visually confirmed in 2006 (see this excellent write up - http://simostronomy..../polaris.html).

I've been officially bitten by the double bug :jump:

Has anyone observed the third alpha UMi Ab?
If you had to pick top 5 double stars most interesting and exciting to observe, what would they be?

Cheers,
Ajith

#2 REC

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Posted 29 June 2013 - 10:49 AM

Good for you, ton's of double stars out there to investigate!

Time for you to track down the most famous of them all, Alberio in Cygnus and the double double in Cygnus!

Welcome to Cloudy Nights!

Bob

#3 obin robinson

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Posted 29 June 2013 - 11:15 AM

I am always mesmerized by Albireo.

http://apod.nasa.gov...d/ap050830.html

obin :jump:

#4 Kfrank

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Posted 29 June 2013 - 11:21 AM

Good for you, ton's of double stars out there to investigate!

Time for you to track down the most famous of them all, Alberio in Cygnus and the double double in Cygnus!

Welcome to Cloudy Nights!

Bob


Both excellent choices - but isn't the Double Double in Lyra?

Also check out Mizar in Ursa Major.

#5 desertlens

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Posted 29 June 2013 - 11:44 AM

You'll need to wait a bit but check out sigma Orionis, a quadruple. Nearby is a nice double, Struve 762. I was surprised at the appeal of doubles. Clear skies and good hunting.

#6 MikeBOKC

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Posted 29 June 2013 - 12:06 PM

Put Beta Monoceros on your winter list - the nicest triple star system in the sky.

#7 kfiscus

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Posted 29 June 2013 - 01:24 PM

52 Cygni. I guess it's a triple. The reason I call it "my favorite star" is that it marks the location of the Veil Nebula. I have to get a really good night to try to separate the members. If I remember correctly, the star(s) aren't related to the nebula.

#8 Kon Dealer

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Posted 29 June 2013 - 02:07 PM

Izar (E. Bootes) is my personal favourite.

#9 S.Boerner

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Posted 29 June 2013 - 02:29 PM

Give the Trapezium in Orion a shot.

#10 Kraus

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Posted 29 June 2013 - 04:36 PM


I'm partial to Izar and Alibero and sigma Orionis. I saw five stars quite easily in sigma Orionis. A sixth star tried to peek out at me.

#11 StarStuff1

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Posted 29 June 2013 - 04:58 PM

Next to Alberio the most beautiful double in the northern hemisphere is gamma andromadae. IMHO.

But one of the most unusual "multiple" star systems is H3780 in Lepus. This might just be a very sparse open cluster but it is very attractive in small scopes and often overlooked by better known targets. Well worth finding this coming Winter.

#12 JIMZ7

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Posted 29 June 2013 - 05:06 PM

I second that for Albireo & Gamma Andromeda as my favorite double stars.

Jim :dob:

#13 Bakes

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Posted 29 June 2013 - 09:15 PM

I'll also vote for Albireo, an old favorite. Alpha Herculis is a close split with nice color contrasts. Castor in the Winter. Mizar itself(not Alcor) splits nicely even in my first 50mm scope. Finally, for the fifth selection, Polaris. It's up all night all year for most of us.

#14 karstenkoch

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Posted 29 June 2013 - 09:21 PM

Scorpius is putting on a good show this time of year in the southern sky for us northern hemisphere observers. Check out Graffias (beta scorpii) for a nice easy bright uneven double. It's the brightest star in the "top" arm of the scorpion. 1 1/2 degrees away is Jabbah (nu scorpii), another relatively bright and pretty uneven double. There's plenty more in the area. If you can, I recommend that you get a decent star altas that shows doubles such as the Cambridge Double Star Atlas to plan your nighttime hunts during the day. Clear skies, Karsten

#15 Perigny270

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Posted 29 June 2013 - 09:26 PM

Many of my favourites have already been mentioned. But I must admit that I look for Antares every chance I get. Nice colour even if the split is difficult - it's a challenge well worth the effort.

#16 fred1871

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Posted 29 June 2013 - 09:58 PM

Nu Scorpii (mentioned above as a wide double) is worth looking at - an easy wide pair at low power, but it's also a "double-double" because each star is a close pair. The brighter star is quite close (~1.3") and somewhat uneven - for northern observers it'll be a matter of steady air to show it; the lesser star is an easier, somewhat wider pair (2.4").

In okay seeing all four will show with a 6-inch Newtonian, not as easy as the Epsilon Lyrae "double-double", but still very nice.

#17 Nucleophile

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Posted 29 June 2013 - 10:37 PM

Cor Caroli is one of my favorites.
But I'll always look at Izar, Albireo, Almach, Trapezium and Antares given a chance.

Rigel, also, is quite beautiful in a simple way.
The double star function of your XT8i is a great way to get introduced to doubles.

I remember being *very impressed* that I could split an even double of 0.9 arcseconds when I first got that instrument--and now I work with it down near the Dawes Limit! What a sturdy, portable, powerful and ergonomic telescope--I'll never part with mine.

#18 ziridava

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Posted 30 June 2013 - 07:47 AM

Why not add Porrima as a Spring favorite and 52 Ori as a Winter favorite.
Then,I'm in big trouble, there are so many beautiful double stars in the sky that I must admit I'm a polygamist in this matter.
All are beautiful in their own way ! I want them all!

Mircea

#19 gfeulner

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Posted 30 June 2013 - 09:13 AM

I know the title is "favorite doubles" but I love triples. Beta Monoceros, Zeta Cancri and Iota Cassiopia among my favorites. Gerry

#20 StarStuff1

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Posted 30 June 2013 - 10:21 AM

Wow, I can't believe no one has mentioned Algieba, gamma leonis. One of my favorite double star experiences was viewing it through holes in the clouds and a light rain falling. With an 80mm refractor it was simply stunning, yellow-green!

#21 AjithSeattle

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Posted 30 June 2013 - 11:23 PM

Albireo is impressive - the contrasting colors sure make this viewing experience memorable. I just saw it yesterday night, loved it! :)

#22 Astrodj

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Posted 01 July 2013 - 12:43 AM

One of my faves for this time of year is Rho Ophiuchus. It's about 3 degrees north of Antares in Scorpius. Check it out. ;)

#23 AjithSeattle

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Posted 01 July 2013 - 09:19 AM

Last night I observed the double-double in Lyra - With my 8" XT8i, I could split the closer double to reveal the individual stars only at large magnification (300x) XT8 has focal length of 1200mm and I used a 4mm Plossl EP to split it.

Then, it was Mizar, again I could spot the Mizar-Alcor but the close double on the Mizar itself, it couldn't be resolved further than a oblong point of light.

Izar (E.Bootes) - I couldn't split it with my scope, I'm sure I'm doing something wrong, it showed up as a orange-yellow point of light but didn't see the bluish companion. I'm doing to try again in the next opportunity I have.

So many more options to look at from all of you, thank you for that.

#24 Nucleophile

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Posted 01 July 2013 - 10:03 AM

Last night I observed the double-double in Lyra - With my 8" XT8i, I could split the closer double to reveal the individual stars only at large magnification (300x) XT8 has focal length of 1200mm and I used a 4mm Plossl EP to split it.

Then, it was Mizar, again I could spot the Mizar-Alcor but the close double on the Mizar itself, it couldn't be resolved further than a oblong point of light.

Izar (E.Bootes) - I couldn't split it with my scope, I'm sure I'm doing something wrong, it showed up as a orange-yellow point of light but didn't see the bluish companion. I'm doing to try again in the next opportunity I have.

So many more options to look at from all of you, thank you for that.


All of those should be easy splits---collimation errors is my guess ( and/or possibly tube currents + improper mirror cool down).

Of course, it could be the mirror also---these are mass produced in China. However, this is usually not the first place to look.

You may wish to spend some time in the reflector forum to learn more about this instrument ( and the fine art of collimation)----many of us have these 8 inch Orion reflectors and the archives are a treasure chest of helpful info. Above all, be patient and get to know the instrument each opportunity you can

#25 phily

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Posted 01 July 2013 - 02:20 PM

I agree with the choice of Albireo, which I think is one of the most beautiful objects in the sky, also Almach. For interest, however, how about Castor?
Phil






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