#1  
Old 09-07-2018, 09:20 AM
Tropo-Bob (Bob)
Registered User

Tropo-Bob is offline
 
Join Date: Sep 2013
Location: Cairns
Posts: 879
OPHIUCHUS - The Grand Tour

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


The Main Stars:

Alpha Ophiuchi (Oph): Rasalhague. A binary with a period about 9 years. Alpha Oph A is almost flying apart because of it high rotational rate and has much higher gravity at its poles compared to its equator.
https://en.wikipedia.org/wiki/Alpha_Ophiuchi

Beta Oph: Cebalrai. Evolving into a giant.
https://en.wikipedia.org/wiki/Beta_Ophiuchi

Gamma Oph: Muliphen. It is radiating an excess emission of infrared, suggesting the presence of a circumstellar disk of dust at an orbital radius of 64 AU from the host star
https://en.wikipedia.org/wiki/Gamma_Ophiuchi

Delta Oph: Yed Prior. A large (59 times the solar radius), but not massive (1.5 Solar masses) red-giant star.
https://en.wikipedia.org/wiki/Delta_Ophiuchi

Epsilon Oph: Yed Posterior. Another red-giant. (10 times Solar raius, but 2 x Solar masses).
https://en.wikipedia.org/wiki/Epsilon_Ophiuchi


Objects of interest.

Rho Ophiuchi Cloud Complex. Hartung's suggests in his book, Astronomical Objects for Southern Telescopes that this nebula can be seen. I had previously thought it appeared only in photographs, so I will try to observe it.
https://en.wikipedia.org/wiki/Rho_Ophiuchi

NGC 6572 Planetary Nebula. Its bright at Mag 8.1, but is only 16x13 arc seconds in size.
https://en.wikipedia.org/wiki/NGC_6572

RS Oph - Recurrent Nova; there have been 8 recorded outbursts, the last being in 2006. It is bright enough to be seen at minimum (Mag 12) and reaches around Mag 5 during outbursts.
https://en.wikipedia.org/wiki/RS_Ophiuchi

NGC 6633. Open cluster. It apparently is large and bright.
https://www.space.com/22400-dazzling...633-photo.html

Barnard 72. The Snake Nebula. I have seen dark patches against the Milky Way, but have never previously tried to identify them.
https://en.wikipedia.org/wiki/Snake_Nebula

Messier objects in Ophiuchus: M9, M10, M12, M14, M19, M62, and M107.
Caldwell Objects in Ophiuchus: Nil.
Reply With Quote
  #2  
Old 09-07-2018, 10:18 PM
Tropo-Bob (Bob)
Registered User

Tropo-Bob is offline
 
Join Date: Sep 2013
Location: Cairns
Posts: 879
My observations

All 5 mains stars in Ophiuchus were easily visible to my eyes, with Beta & Gamma forming the lower set of hands to hold the Serphents tail and Delta & Epsilon being the upper hands holding the Serpens body, just below its head (Serphens Caput).

I mostly used my Vixen 115mm ED (FL 890mm), on an Eqz mount and 24mm, 15mm, & 7mm. For the Rho Ophiuchi Cloud complex, I used a 80mm (F6) Orion triplet. Then I started swapping scopes and used my Vixen 140mm.


Objects of interest.

Rho Ophiuchi Cloud Complex. Hartung's suggests in his book, Astronomical Objects for Southern Telescopes that this nebula can be seen. I had previously thought it appeared only in photographs...
Because of its large area, I used the 80mm triplet to observe the complex. The interesting double, Rho is certainly a great signpost that enabled me to know that I was looking at the correct area.
The 'complex' looked very large in the 80mm, even at 20x using a 24mm panoptic EP. Though it surrounded Rho, the larger and thicker part was to the East. It has a cold-grey tint and could be seen in its own right without needing to use a silhouette affect. That said, it was notable how fewer stars were seen in the area.

NGC 6572 Planetary Nebula. Its bright at Mag 8.1, but is only 16x13 arc seconds in size.
Using the 115mm at 37x (24mm EP), the aqua colour showed in the planetary even though it otherwise just looked like a star. The nebula took magnification well and looked best with a 7mm Delite, with which it appeared as small, bright and round.

RS Oph - Recurrent Nova; there have been 8 recorded outbursts, the last being in 2006. It is bright enough to be seen at minimum (Mag 12) and reaches around Mag 5 during outbursts.
This star was visible with the 115mm using only 37x. It, as expected, it is in its quite state awaiting its next outburst. There is a chart on P1245 of Burnham's Handbook that helps with identification.

NGC 6633. Open cluster. It apparently is large and bright.
A scattering of roughly 30 bright stars that crossed the diameter of field of a 15mm Delite EP (60x). Its shape is roughly rectangler rather than round. Nevertheless, it is somewhat difficult to establish if the fainter stars seen belonged to the cluster or if they belonged to the foreground or background

Barnard 72. The Snake Nebula. I have seen dark patches against the Milky Way, but have never previously tried to identify them.
I found this frustrating and resorted to using my 140mm to obtain a better view. I could see lanes in the correct area but could not follow the shape fully. It was best seen with at 53x (15mm Delite EP).


The Main Stars:

Alpha Ophiuchi (Oph): Rasalhague.
This is the brightest star in the constellation and it appears white.

Beta Oph:
This appeared orange, but the longer I viewed it, I also thought at times its colour sometimes appeared to be a deep-gold.

Gamma Oph: Muliphen.
This appeared blue-white.

Delta Oph: Yed Prior. A large (59 times the solar radius), but not massive (1.5 Solar masses) red-giant star.
I saw this as being medium-orange.

Epsilon Oph: Yed Posterior. Another red-giant. (10 times Solar raius, but 2 x Solar masses).
This appeared to be a light-orange.
Reply With Quote
  #3  
Old 10-07-2018, 08:44 AM
Tinderboxsky's Avatar
Tinderboxsky (Steve)
I can see clearly now ...

Tinderboxsky is offline
 
Join Date: Feb 2012
Location: Tinderbox TAS
Posts: 652
Interesting report Bob. You seem to be enjoying a string of clear observing nights. Is it the season up there for clear nights? Clear nights are few and far between down here at the moment. Then a clear night comes along and I cannot get out because of existing commitments.
Reply With Quote
  #4  
Old 10-07-2018, 01:05 PM
Tropo-Bob (Bob)
Registered User

Tropo-Bob is offline
 
Join Date: Sep 2013
Location: Cairns
Posts: 879
Thanks Steve,

June to December is the better time of the year for stargazing. I seem to have had more luck than normal this year, even though it was very wet here earlier.

I hope your weather improves soon, as I also enjoy reading your reports.
Reply With Quote
  #5  
Old 05-09-2018, 08:38 PM
Tinderboxsky's Avatar
Tinderboxsky (Steve)
I can see clearly now ...

Tinderboxsky is offline
 
Join Date: Feb 2012
Location: Tinderbox TAS
Posts: 652
I completed Bobís tour of Ophiuchus back on the 14th July, but had missed posting my observations. So, a belated catchup. The night was clear with seeing about 4.5/5 and transparency 6/7.

I toured the main stars at 36X.

Rasalhague: blazing white-yellow with scattered fine faint star field background.
Cebalrai: bright yellow-white.
Gamma: white
Yed Prior: bright orange and nicely framed in the same FOV with Yed Posteria: slightly fainter orange.

Then it was on to the objects of interest. All of these were observed at 62X:

Rho Cloud complex: faint misty haze, slightly brighter towards the centre. It was better and slightly more defined with averted vision.
NGC 6572 @ 160X: distinct very small whitish-blue round planetary.
NGC 6633: pretty open cluster of 20 plus stars against a scattered star field. Brighter field star near cluster.
RS Ophiuchus: faint white end star of eight stars of similar magnitude that form a distinct crescent.
Barnard 72 (The Snake Nebula): My notes do not have any reference to this nebula and I cannot remember it on the night. I suspect I missed it.
M14: broad diffuse glow, brighter towards the centre but not central bright spot.
M10: broad diffuse area, slightly brighter towards the centre. Stars appeared on the edge of resolution giving a mottled effect. A spray of outer stars added to the effect.
M12: fainter glow with resolved stars across the face with averted vision.
M107: faint glowing patch.
M9: faint glowing patch with a broad slightly brighter central area.
M19: faint road patch with slightly brighter central region.Some mottling across the face.
M62: brighter and more condensed with a very regular circular shape. Brighter central region.

Vixen NA140SS on TRex with LVW 22 (36X) & 13 (62X) eyepieces. Navigation using Sky Safari 6.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 08:50 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
NexDome Observatories
Advertisement
Bintel
Advertisement
Meade Australia
Advertisement
SkyWatcher Australia
Advertisement
OzScopes Authorised Dealer
Advertisement
Lunatico Astronomical
Advertisement
Celestron Australia
Advertisement
Astronomy and Electronics Centre
Advertisement