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Old 25-09-2019, 01:16 AM
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A long time ago in a galaxy far, far away....

Hi All,

Managed to put a tick in the little box on a project I've been waiting to tackle for about nine months.

Predictably yes, I saw another very small, very faint galaxy. This one's a bit special -- ESO 146-8 close-by to the Indus-Tucana border.

With a B magnitude of 16.76, yes, it is very, very faint even for a 63.5cm telescope -- the B magnitude corresponds to a true visual magnitude of about 15.8. It isn't a QSO or a BL Lacertae type super-luminous object with an active nucleus -- it's just a "normal" galaxy.

Not big either 1.1 x 0.3 arc minutes in extent. There are literally tens of thousands of galaxies of this sort visible in very large amateur telescopes, so, why this one?

The answer lies in its red-shift: (z)1.76884 that yields a recessional velocity of 48,400 km/sec ... or about 16% of c.

Plug a Hubble constant of 71.5km/sec/Mpc into that and assume a flat geometry for the Universe, it implies a whopping distance (more accurately look-back time) (ie for how long have these photons been travelling) of 2.206 billion light years.

This is the most distant "normal" galaxy I've personally ever observed. It broke my previous distance record by about 900 million ly.

Happily, there is a distinctive, compact bunch of magnitude 13-15 stars immediately to its south that made pinpointing the exact spot quite easy. At x347, it was intermittently visible, glimpsed occasionally every several seconds as the seeing came and went, about 10" diameter but no visible structure.

I've attached a DSS image -- north is up and east to the left. Yes that's it right in the centre -- the tiny, apparently face-on barred spiral that also seems to be interacting with another yet fainter galaxy immediately north.

Happy observer retires to bed!

Best,

L.
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Last edited by ngcles; 25-09-2019 at 01:31 AM.
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Old 25-09-2019, 06:18 AM
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Atmos (Colin)
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That is a dim tiny little sucker! When you have the aperture, chase them down
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Old 25-09-2019, 08:20 AM
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Impressive. Far far away in time indeed.
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Old 25-09-2019, 08:28 PM
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Good Catch Les.
I will attempt it in the 16"
Cheers
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Old 26-09-2019, 12:22 AM
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Second prize?

Hi Ron & All,

Quote:
Originally Posted by astroron View Post
Good Catch Les.
I will attempt it in the 16"
Cheers
If you don't succeed, there is a nice consolation prize only one low-powered power field away (52 arc mins SSW) -- ESO 146-5.

In this case, it is a supergiant "CD" type elliptical near or at the centre of AGC 3827. It is about a magnitude brighter than ESO 146-8 and I have seen it previously with 46cm. It has a R/V of +29980 and therefore lies nearly 1.4 billion light-years distant.

A 10' x 10' of ESO 146-5 is attached N is up and E is left.

Best,

L,
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Old 26-09-2019, 08:47 AM
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Quote:
Originally Posted by ngcles View Post
Hi Ron & All,



If you don't succeed, there is a nice consolation prize only one low-powered power field away (52 arc mins SSW) -- ESO 146-5.

In this case, it is a supergiant "CD" type elliptical near or at the centre of AGC 3827. It is about a magnitude brighter than ESO 146-8 and I have seen it previously with 46cm. It has a R/V of +29980 and therefore lies nearly 1.4 billion light-years distant.

A 10' x 10' of ESO 146-5 is attached N is up and E is left.

Best,

L,
Thanks Les,will add that to my observing list.
One of my favourite observing targets is the ESO 137-6 and the group round it.
It is also situated on the Norma, Triangulem Australe border.
If you haven't observed it it would be a good target for your scope.
Cheers
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Old 26-09-2019, 10:09 AM
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Quote:
Originally Posted by ngcles View Post
Hi Ron & All,



If you don't succeed, there is a nice consolation prize only one low-powered power field away (52 arc mins SSW) -- ESO 146-5.

In this case, it is a supergiant "CD" type elliptical near or at the centre of AGC 3827. It is about a magnitude brighter than ESO 146-8 and I have seen it previously with 46cm. It has a R/V of +29980 and therefore lies nearly 1.4 billion light-years distant.

A 10' x 10' of ESO 146-5 is attached N is up and E is left.

Best,

L,
Found this article https://www.cbsnews.com/news/record-...alaxy-sighted/
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Old 27-09-2019, 08:56 PM
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Zubenel (Wes)
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Thx Les. We do have our work cut out !Along with Gomez's Hamburger before it sets, Ron
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Old 29-09-2019, 06:36 PM
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20" success

Hi All,

Had an observing weekend down at a friend's place near Crookwell (I took the 46cm f/4.9") and last night, tried for ESO 146-8 with that 'scope and failed. However it was visible in a friends 50cm f/5 -- bare detection. Occasionally visible at x277 several times a minute as a tiny, almost stellar diffuse spot.

It is important to use the nearby star-pattern to locate the precise location -- it will not be visible with a casual glance.

Nearby ESO 146-5 was faint but you can almost hold it steadily using averted vision with 46cm and a simple, very small moderately faint spot in 50cm.

Best,

L.

Last edited by ngcles; 29-09-2019 at 08:10 PM.
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Old 04-10-2019, 02:38 AM
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Ngc 1262

Hi All,

If you are interested in seeing these ultra distant objects, here's another one that is apparently visible in a 10" 'scope (I'm told) -- NGC 1262 in Eridanus.

SIMBAD provides an R/V of 34674km/sec from a red-shift of z(~) 0.123198 that gives a look-back time of about 1.58 Gly. It is apparently the most distant object in the NGC that was discovered visually. (Francis Leavenworth)

Here is a note I made with my 46cm f/4.9 at x247 in 2011 at Mudgee under a dark sky with an SQM-L reading of 21.77:

This galaxy appears to the NNW of a loose bunch of stars magnitudes 11.5 - 13. Small, nondescript and quite faint. Round, only about 20-30" diameter brightening slightly to centre without core or nucleus. Pretty LSB.

"Quite faint" isn't too bad in my books. Very faint and extremely faint are worse than that so I'd suggest that apertures around the 10-12" might just be a chance of snaring it in excellent conditions.

Best,

L.

Last edited by ngcles; 07-10-2019 at 01:01 PM.
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Old 06-10-2019, 09:56 PM
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That's quite an achievement, Les. Bigger scope aswell, do post reports of your future adventures, 25 inches in your hands is a formidable force! And yes, few things rival the satisfaction of going to bed after a good session!
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Old 07-10-2019, 01:00 PM
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Agc 3627 & eso 137-6

Hi Ron & All,

Quote:
Originally Posted by astroron View Post
One of my favourite observing targets is the ESO 137-6 and the group round it.
It is also situated on the Norma, Triangulem Australe border.
If you haven't observed it it would be a good target for your scope.
Cheers
Ah yes the Abell cluster (AGC 3627) near the purported centre for the "great attractor".

Have tilled that ground a few times myself in my old 30cm and the 46cm. I think it is quite a challenging cluster to (visually) observe due to the blizzard of faint foreground stars. Makes tracking-down, finding and seeing the little 'uns a pain in the neck.

Perhaps a little tangential to the thread topic, here are my notes of AGC 3627 made from Mudgee about 2am, 18th April 2010 with the 46cm f/4.9 at x120 and x247. The SQM-L reading was 21.62 and seeing was 6/10:

PGC 57532 (ESO 137-1) Gx Triangulum Australe
46cm x247: ESO 137-8 is the brightest of a large number of galaxies in AGC 3627 that includes ESO 137-1 (PGC 57532) 20’ NW, ESO 137-2 (PGC 57537) 16’ WNW, ESO 137-3 (PGC 57546) 16’ SW, ESO 137-6 (PGC 57612) 5’ WNW, ESO 137-7 (PGC 57637) 15’ N, ESO 137-10 (PGC 57652) 7’ NNE, ESO 137-11 (PGC 57656) 4’ NE and ESO 137-16 (PGC 57815) 26’ ESE. This is a challenging and frustrating galaxy cluster to observe because to the richness of the star-fields and the bright background due to the Milky Way. Makes identification difficult because star-patterns are very easy to confuse because there simply are so many stars. All these galaxies have low to very low surface brightnesses and it is nearly impossible to properly estimate sizes in the eyepiece because of the brightness of the background sky. From the trio of ESO 137-6, ESO 137-8 and ESO 137- 10 5, one field W is the 15' long line of ESO 137-1, ESO 137-2, ESO 137-4 & ESO 137-3 running N-S. ESO 137-4 is almost between ESO 137-2 & ESO 137-3 as a tiny 20" diameter round spot of gossamer hardly brighter than the background as is ESO 137-1 at the N end of this line.

PGC 57537 (ESO 137-2) Gx Triangulum Australe
46cm x247: From the trio of ESO 137-6, ESO 137-8 and ESO 137- 10 5, one field W is the 15' long line of ESO 137-1, ESO 137-2, ESO 137-4 & ESO 137-3 running N-S. Of this four, ESO 137-2 & ESO 137-3 are the brightest though ESO 137-3 has lower SB and is a little bigger. ESO 137-3 is about 1' x 40" and brightens weakly to centre and has very LSB. ESO 137-2 is smaller, about 40" diameter, round but has better SB brightening slightly to centre.

PGC 57546 (ESO 137-3) Gx Triangulum Australe
46cm x247: From the trio of ESO 137-6, ESO 137-8 and ESO 137- 10 5, one field W is the 15' long line of ESO 137-1, ESO 137-2, ESO 137-4 & ESO 137-3 running N-S. Of this four, ESO 137-2 & ESO 137-3 are the brightest though ESO 137-3 has lower SB and is a little bigger. ESO 137-3 is about 1' x 40" and brightens weakly to centre and has very LSB. ESO 137-2 is smaller, about 40" diameter, round but has better SB brightening slightly to centre.

PGC 557554 (ESO 137-4) Gx Triangulum Australe
46cm x247: From the trio of ESO 137-6, ESO 137-8 and ESO 137- 10 5, one field W is the 15' long line of ESO 137-1, ESO 137-2, ESO 137-4 & ESO 137-3 running N-S. ESO 137-4 is almost between ESO 137-2 & ESO 137-3 as a tiny 20" diameter round spot of gossamer hardly brighter than the background as is ESO 137-1 at the N end of this line.

PGC 57612 (ESO 137-6) Triangulum Australe
46cm x247: ESO 137-6, ESO 137-8 & ESO 137-10 in a triangle with ESO 137-10 at the northern tip. This triangle is about 6 arc-mins a side. ESO 137-10 is seen to be slightly elongated in PA 0 and is the brightest of all. It has a short line of three magnitude 12-13 stars not far to the W. 1.5' x 40" in PA 0 and has a small slightly brighter core. ESO 137-06 & ESO 137-08 are E-W of each other and are simple, approximately 1' diameter spots of LSB haze brightening slightly to centre. Between ESO 137-10 & ESO 137-8 is ESO 137-11 which is somewhat to much fainter -- a spot of mist perhaps 30" diameter with a weak central brightening.

PGC 57637 (ESO 137-7) Gx Triangulum Australe
46cm x247: A line extended from ESO 137-8 through ESO 137-10 and extended N about 10’ sees ESO 137-7 that is similar to ESO 137-11 though it has slightly higher SB.

PGC 57649 (ESO 137-8) Gx Triangulum Australe
46cm x247: The major three galaxies here are ESO 137-6, ESO 137-8 & ESO 137-10 in a triangle with ESO 137-10 at the northern tip. This triangle is about 6 arc-mins a side. ESO 137-10 is seen to be slightly elongated in PA 0 and is the brightest of all. It has a short line of three magnitude 12-13 stars not far to the W. 1.5' x 40" in PA 0 and has a small slightly brighter core. ESO 137-06 & ESO 137-08 are E-W of each other and are simple, approximately 1' diameter spots of LSB haze brightening slightly to centre.

PGC 57652 (ESO 137-10) Gx Triangulum Australe
46cm x247: ESO 137-6, ESO 137-8 & ESO 137-10 in a triangle with ESO 137-10 at the northern tip. This triangle is about 6 arc-mins a side. ESO 137-10 is seen to be slightly elongated in PA 0 and is the brightest of all. It has a short line of three magnitude 12-13 stars not far to the W. 1.5' x 40" in PA 0 and has a small slightly brighter core. ESO 137-06 & ESO 137-08 are E-W of each other and are simple, approximately 1' diameter spots of LSB haze brightening slightly to centre. Between ESO 137-10 & ESO 137-8 is ESO 137-11 which is somewhat to much fainter -- a spot of mist perhaps 30" diameter with a weak central brightening.

PGC 57656 (ESO 137-11) Gx Triangulum Australe
46cm x247: Between ESO 137-10 & ESO 137-8 is ESO 137-11 which is somewhat to much fainter -- a spot of mist perhaps 30" diameter with a weak central brightening.

PGC 57815 (ESO 137-16) Gx Triangulum Australe
46cm x247: Far off the E side of the cluster ESO 137-16 sits all by itself -- a small 30" diameter spot of very LSB mist with no detectable brightening to centre.


Best,

L.

Last edited by ngcles; 07-10-2019 at 01:40 PM.
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