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  #1  
Old 22-04-2018, 09:03 AM
Tropo-Bob (Bob)
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LIBRA - The Grand Tour

Libra is best known as the Scales of Justice, and the inverted, V- shape scales are very obvious to the casual observer. However, the constellation has had a bit of an identity crisis because of being associated with the Claws of the Scorpion. Indeed, it was not till 1930 that the southern end of the scales had it designation changed from Gamma Scorpio to Sigma Librae.

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

The Main Stars:

Alpha Librae. A very wide double. https://en.wikipedia.org/wiki/Alpha_Librae
Beta Librae.(old observations described it as Green in colour) https://en.wikipedia.org/wiki/Beta_Librae
Gamma Librae https://en.wikipedia.org/wiki/Gamma_Librae
Eplison Librae https://en.wikipedia.org/wiki/Epsilon_Librae
Sigma Librae https://en.wikipedia.org/wiki/Sigma_Librae (Orange or red in colour?)


Other objects of interest:

The Methuselah Star. This Star caused a lot of interest only a few years back when its age was estimated to be older than the age of the Universe. This ancient star is only 190 light years from us. It is part of an ancient halo of stars around our Milky way and just happen to be currently speeding through our region.
https://en.wikipedia.org/wiki/HD_140283
https://www.nasa.gov/mission_pages/h.../hd140283.html


Delta Librae. A variable star, whose brightness varies by about a magnitude over a 2.3 day period. It is of the Algol type.
https://en.wikipedia.org/wiki/Delta_Librae


Mu Librae. A close double. https://en.wikipedia.org/wiki/Mu_Librae


ShJ 179 14h.25.5m -19.58 (Hartung handbook 641)
Wide double: mags 6.6 & 7.2. The secondary is a close double with a seperation of approximately 1 arc second.

NGC 5897. A globular cluster. https://en.wikipedia.org/wiki/NGC_5897
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  #2  
Old 23-04-2018, 07:55 AM
Tropo-Bob (Bob)
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My observations

Fortune smiled on me last night and I was able to view these with my 100mm, F7.4 Tak.


Objects of interest:

The Methuselah Star.
I felt quite insignificant when I viewed this ancient star, which was born when the universe was young. Comparing my age to the 14 billion of the star, I reflected on how my lifespan was fleeting and rather insignificant in the scheme of things. Humbling!

The star was located with only a little bit of star hoping. It is the middle and brightest star of three stars shaped into a gentle bow. It is said to be in it's later life and becoming a giant. Even so, I could not see any hint of colour. One end of the bow featured a faint (Mag 8/9?) pair of stars that was nicely separated (at 30x). I mention this only as a reference point for others to know that they are in the correct region, if they try to view this remarkable star.

Delta Librae. (Variable)
Delta was visible to the unaided eye with a little bit of effort. It appeared white and to be at full brightness at the moment. Using binoculars, I found 2 reference stars that I hope to use over the next few weeks to be able to monitor its dips in brightness.

Mu Librae. A close double.
Using a 5mm Delite (148x), I was able to see this as a figure 8. It was split cleanly using a 4mm Radian (185x). They appeared to be a slightly uneven pair, which were white in colour.

ShJ 179 14h.25.5m -19.58 (Hartung handbook 641)
I have read descriptions of doubles looking like a pair of eyes looking back at you, but this has never happened to me till now. It was rather strange and eerie. I notice Hass described it as " as a haunting sight'.

The stars appeared white and formed a wide double, which was very easily seen at 30x. The fainter of the pair is a close double, which I could not split with a 3.5mm Nagler.

NGC 5897. A globular cluster.
A loose globular that I could see before the 6 day-old Moon set, but it appeared much better afterwards. I could see granulation with hints of resolution of individual stars using an 11mm Nangler (67x).


The Main Stars.

Visually, only 4 stars in the Constellation jumped out at me without having to search for them nearer the limits of vision. The easiest 3 stars form the Scales (Beta, Alpha & Sigma), whilst the remaining star (Gamma) is still often referred to as being one of Scorpios claws.

Alpha Librae. The central star of the scales is a very wide double. The primary appeared white, the secondary appeared yellow.

Beta Librae.(old observations described it as Green in colour)
It appeared white to me.

Gamma Librae. It appeared yellow.

Eplison Librae. It appeared white.

Sigma Librae (Orange or red in colour?)
It appeared light orange to me.
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  #3  
Old 18-05-2018, 07:33 AM
Tropo-Bob (Bob)
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Jupiter is currently in Libra, so this constellation is rather prominent ATM.

I have being trying to observe the variable, Delta. However, I have not noticed any changes, even though it variation occurs in some 2.3 days and has about a variation of about a magnitude. Last night was a wash out, but I observed it on the previous 3 evening with binoculars and intermittently on occasions before that.

Quote:
Originally Posted by Tropo-Bob View Post

NGC 5897. A globular cluster.
A loose globular that I could see before the 6 day-old Moon set, but it appeared much better afterwards. I could see granulation with hints of resolution of individual stars using an 11mm Nangler (67x).
I observed this with my 8" SCT on May 14th. The haze of loose stars within the globular seemed appreciably better with a 24mm EP (85x) than with either 32mm or 16mm EPs.
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  #4  
Old 19-05-2018, 08:50 AM
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Tinderboxsky (Steve)
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It was a clear night here in Eden, so I decided to take your "Grand Tour" using my 6.5X32 wide field binoculars. The sky was quite dark but there were a few annoying lights nearby.
All of the main stars outlining the scales were clear naked eye, with Jupiter dominating the constellation.

Through the binoculars:
Alpha - white primary and wide pale yellow companion
Beta - white with hint of yellow
Sigma - orange
Gamma - whiteish yellow
Upsilon - orange red
Theta - orange.

I made the easy star hop to The Methuselah Star HD140283. It was too faint for me to see any colour. A star with an interesting story for sure.

Delta Librae showed white and appeared to be near it's brightest when trying to compare it's magnitude with nearby companions. I notice the full drop in brightness occurs over about six hours and then it takes about two days to get back to full brightness. I shall try to remember to revisit this star.

I "tripped over" Nu Librae which appeared very red - a red giant. Nu Librae and the nearby star HD133800 formed an almost mirror image to Alpha Librae and it's companion with Jupiter almost exactly in the middle. An interesting temporary asterism which will disappear as Jupiter moves on.

I noticed the area is rich in red giants showing their colours clearly:
Kappa - red
42 Librae - orange

I looked for the globular NGC 5897. I could locate it's position without difficulty, but could not see it through the 6.5X32 bins. I could just make a faint smudge with 7X50 bins.

All in all a very enjoyable and instructive tour. Thank you Bob. May there be more.
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  #5  
Old 20-05-2018, 08:12 AM
Tropo-Bob (Bob)
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Quote:
Originally Posted by Tinderboxsky View Post
...I made the easy star hop to The Methuselah Star HD140283. It was too faint for me to see any colour. A star with an interesting story for sure.

Delta Librae showed white and appeared to be near it's brightest when trying to compare it's magnitude with nearby companions. I notice the full drop in brightness occurs over about six hours and then it takes about two days to get back to full brightness. I shall try to remember to revisit this star.

I "tripped over" Nu Librae which appeared very red - a red giant. Nu Librae and the nearby star HD133800 formed an almost mirror image to Alpha Librae and it's companion with Jupiter almost exactly in the middle. An interesting temporary asterism which will disappear as Jupiter moves on.

I noticed the area is rich in red giants showing their colours clearly:
Kappa - red
42 Librae - orange ...
Thanks for your remarks and observations Steve.

Now U have motivated me to revisit and view Nu Librae. Indeed, also to sweep the constellation further with binoculars.

That was useful information re Delta. I will keep checking.

I am glad that U also viewed the ancient Methuselah Star HD140283. I doubt that more than a handful of people have deliberately seen this.

I am planning to continue the 'Grand Tour'; I have just been a little sidetracked by Jupiter.
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  #6  
Old 31-05-2018, 07:38 PM
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Quote:
Originally Posted by Tinderboxsky View Post

...Delta Librae showed white and appeared to be near it's brightest when trying to compare it's magnitude with nearby companions. I notice the full drop in brightness occurs over about six hours and then it takes about two days to get back to full brightness...
I checked Delta out with binoculars this evening (about 7.40pm) and am happy to say that I have finally caught this variable near its minimum. I compared it to several nearby stars and I could see that it was distinctly fainter than normal.
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  #7  
Old 31-05-2018, 08:16 PM
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Tinderboxsky (Steve)
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Excellent catch Bob.
I have just been outside to have a look with binoculars. The sky is clear but I am in the middle of Melbourne and everything is washed out. So, no sighting for me. I will have to try for another minimum.
I have been trying for a while to observe Algol at one of it's minimums. It is real challenge here as Algol is very low in the north and only above the horizon for a few hours each night.

Quote:
Originally Posted by Tropo-Bob View Post
I checked Delta out with binoculars this evening (about 7.40pm) and am happy to say that I have finally caught this variable near its minimum. I compared it to several nearby stars and I could see that it was distinctly fainter than normal.

Last edited by Tinderboxsky; 03-06-2018 at 10:15 AM. Reason: Correction
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  #8  
Old 03-06-2018, 08:09 AM
Tropo-Bob (Bob)
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Quote:
Originally Posted by Tropo-Bob View Post
Jupiter is currently in Libra, so this constellation is rather prominent ATM...

I observed this (Globular NGC 5897 with my 8" SCT on May 14th. The haze of loose stars within the globular seemed appreciably better with a 24mm EP (85x) than with either 32mm or 16mm EPs.
I went bush last night and spent a few hour observing near Mareeba with my Vixen 140mm. A dark sky effectively adds inches to the aperture; I was in seventh heaven looking at the stars, clusters, globulars and nebulae along the Milky Way and at galaxy clusters to the north.

So not surprising, when I viewed NGC 5897, I also thought this looked impressive. It is a very loose haze of stars for a globular. It looked better using the 140mm at this location than it did with the 8" SCT from my backyard. However, using a low magnification is a key factor. It was best with the 24mm Panoptic (33x) than using 44x or 72x.
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