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Old 28-06-2018, 09:28 AM
Tropo-Bob (Bob)
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SCORPIUS - The Grand Tour

Below are the subjects in Scorpio that I wish to view:-

The Main Stars:

Alpha Scorpii (SCO) - Antares. A red super-giant, and a famed double star for observers. I have previously split this double only with a SCT, or with a green filter or when the Moon has occutled Antares.
https://en.wikipedia.org/wiki/Antares

Beta Sco - Acrab. A fine binary and an extraordinary multiple-star system.
https://en.wikipedia.org/wiki/Beta_Scorpii

G Sco - Fuyue. There is no Gamma Sco, as this star was once Gamma Telescopium and has been redesignated to Scorpio. I can not quite follow the narrative as to why it is only called G, and not Gamma.
https://en.wikipedia.org/wiki/G_Scorpii

Delta Sco - Dschubba. This star has varied in brightness over the years.
https://en.wikipedia.org/wiki/Delta_Scorpii
http://www.skyandtelescope.com/astro...ter-than-ever/

Epsilon Sco - Larawag. An orange giant.
https://en.wikipedia.org/wiki/Epsilon_Scorpii



Objects of interest.

Xi Sco - Triple star. Normally seen a Mag 4 & 7 stars with a separation of 7.6 arc seconds. However, the brighter star is a binary with roughly equally bright components. They have a period of 46 years and are now approaching the widest part of their orbit. (Burnham's Handbook has a good diagram of the orbit).
http://stars.astro.illinois.edu/sow/xisco.html

NGC 6153 Planetary Nebula
https://www.spacetelescope.org/images/potw1525a/

NGC 6139 Globular.
http://www.sci-news.com/astronomy/hu...139-06131.html

NGC 6388 Globular
https://www.spacetelescope.org/images/heic1221a/

U Sco - Recurrent Nova; due to recur again anytime between now and another 4 years.
https://en.wikipedia.org/wiki/Scorpius


Messier objects in Scorpio. M4, M6,M7 & M80
Caldwell Objects in Scorpio. 69, 75 & 76.
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Old 28-06-2018, 10:59 PM
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ngcles
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Hi Bob & All,

I'd suggest you take a look at the southern double-double Mu Scorpii which is undoubtedly the showpiece multiple star in Scorpius.

Here are my notes from 1998 using 25cm when I found all four were easy to resolve at just x138:

"The beautiful ** ** The A pair is mags 4.0 & 5.5 sep by approx 1.3" in PA 10, The B pair are considerably easier mag 6.5 7.5 3' sep in PA 60 found in PA 330 from the A pair. All seem white."

It is a good object with which to test the seeing before embarking on planetary observing. The closer pair are only 1.3" sep and if cleanly split at moderate magnification, the seeing is at least good.

As for why g Scorpii is designated in this way, see:

https://en.wikipedia.org/wiki/Bayer_designation

Best,

L.
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Old 05-07-2018, 09:51 AM
Tropo-Bob (Bob)
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My observations

My criteria of only looking at the 5 mains stars in a constellation do not really do justice to Scorpius, which has so many bright stars. Nevertheless, it captures a good sample of stars that are of significant interest.

I used my Meade 127mm ED (F 9), on an eq mount and 32mm, 15mm, 10mm, 7mm & 5mm EPs. By local standards, the seeing last night was normal. However, clouds almost forced me to give up for the evening.


Objects of interest.

Xi Sco - Triple star. Normally seen a Mag 4 & 7 stars with a separation of 7.6 arc seconds. However, the brighter star is a binary with roughly equally bright components. They have a period of 46 years and are now approaching the widest part of their orbit.

I was thrilled to resolve the AB pair using 228x. In fleeting moments, I thought I saw a clean split but these moments were neither long or frequent enough to firmly establish this. Nevertheless, I could see two distinct centers contained within the framework of a figure 8. Both stars were yellow and near equal in magnitude.

The C star was a relatively wide star away from the AB pairing. The C companion appeared about 3 magnitudes fainter (actually it is only 2.4 according to Haas) and to have a deep-orange hue. Other observers have described it as blue, so I am interested to hear other opinions regarding the colour.

NGC 6153 Planetary Nebula
This Planetary was faint and very round with just a hint of being aqua in colour. It took magnification well. It was distinct at 76x, best at 114x, but was surprisingly well defined and large at 163x.

Interestingly, I thought the pale-aqua hue was because it was so faint, but the Hubble photo of this planetary also shows it to be rather pale in hue compared to those planetaries that normally show the aqua colouring.

NGC 6139 Globular.
This showed as a faint, small patch, which I may have missed with the 32mm (36x) if I had not been looking for it. With the 15mm (76x), no condensation of the center was seen. Using 163x, I found it difficult to even view this globular.

If star hoping to this or the above mentioned, nearby planetary, the large, bright open cluster NGC 6124 is a good starting point.

NGC 6388 Globular
Bright, small and highly condensed. No individual stars were seen, but it did look granny at 163x.

U Sco - Recurrent Nova; due to recur again anytime between now and another 4 years.
No outburst was seen. I star hoped to the correct area. Stars in the region were below mag 10, but in the wrong position to be U Sco. I probably need a better chart if I was to continue observing this for outbursts.


The Main Stars:

Alpha Scorpii (SCO) - Antares. A red super-giant, and a famed double star for observers. I have previously split this double only with a SCT, or with a green filter or when the Moon has occutled Antares.

Well, same of old story. I could resolve this only with the aid of a dark-green filter, using 228x. Intriguingly though, this tends to support the notion that the companion is really green and that this is not a false illusion within the eye caused by colour contrasts.

Has anybody else ever used a green filter to see Antares B?


Beta Sco - Acrab. A fine binary and an extraordinary multiple-star system.
This is very easily resolved. Using 36x, the pair looked white and off-white and with a difference of about 2 magnitudes in brightness.
I remeber spliting this with a small Carton 60mm F7 achromat using only 14x, so this is a really easy double to view.

G Sco - Fuyue. There is no Gamma Sco, as this star was once Gamma Telescopium and has been redesignated to Scorpio.
This is said to be an orange K giant star, but I saw it as being deep-yellow in colour.

It's near impossible to look at this star without seeing the nearby globular NGC 6441. As a side project, I will look at this one evening and see how small a telescope I can use to see this fainter globular.


Delta Sco - Dschubba. This star has varied in brightness over the years.
This blue-white star still looks much brighter than when I first was thrilled with this constellation as a teenager in the late 1960s.

Epsilon Sco - Larawag. An orange giant.
What they call orange often looks deep yellow to me and well, it happened again.


Ngcles recommendation:

Mu Sco.
These two pairs looked like just 2 single stars in a wide double using 36x. The brighter star appeared white and the other appeared dull red. There was a difference of about 2.5 magnitudes in brightness.

The dull red star was resolved into a double at 76x. AT 163x, its components appeared as being about half a magnitude different in brightness.

Using 228x, the yellow star was not resolved clearly. The companion did show in the shape of a pimple or bulge on the outside of the main star.

I thought this was a tougher test than the double-double in Lyra.
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