Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Distant Galaxies and Clusters

dob dso observing sketching
  • Please log in to reply
220 replies to this topic

#176 Redbetter

Redbetter

    Cosmos

  • *****
  • Posts: 9,130
  • Joined: 16 Feb 2016
  • Loc: Central Valley, CA

Posted 09 September 2019 - 05:20 AM

I have not observed that many near 3 billion light years.  I covered the main ones that I recall in the thread about it and they are all massive galaxies.   I go past 2 at times when I start targeting some of the dimmer Abell clusters or if they happen to be in the field, but I really haven't kept track of them as a class. There was one recently at a little under 1.75 billion light years, PGC 200336. tucked between another pair with another gx forming the group VV129 in Hercules.  The PGC runs somewhere in the 17+ g mag range. 


Edited by Redbetter, 09 September 2019 - 05:21 AM.


#177 quazy4quasars

quazy4quasars

    Ranger 4

  • *****
  • Posts: 373
  • Joined: 12 Jul 2014
  • Loc: Northern Sierra Foothills, CA.

Posted 09 September 2019 - 12:13 PM

I have not observed that many near 3 billion light years.  I covered the main ones that I recall in the thread about it and they are all massive galaxies.   I go past 2 at times when I start targeting some of the dimmer Abell clusters or if they happen to be in the field, but I really haven't kept track of them as a class. There was one recently at a little under 1.75 billion light years, PGC 200336. tucked between another pair with another gx forming the group VV129 in Hercules.  The PGC runs somewhere in the 17+ g mag range. 

Yeah, these suckers are darn faint.  I keep wanting to try for a little further, but I find I need ideal conditions to have even a hope of a (mostly direct) view of anything around or beyond z~.2... maximum contrast and high-power seeing both required.  Next up for me is  SDSS J215541.97+123128.5  (Ogle 0023) BCG of Abell 2396- at z~.193 - when I get back "up the hill", along with a (barely) direct sighting of A2261, hopefully...   meantime, I'm revisiting deep QSOs (easier) and soaking up Summer Milky Way splendors (easier and prettier!), anyway, thanks Red.  Sure hoping the smoke holds off. 

   

We'll see...


Edited by quazy4quasars, 09 September 2019 - 04:06 PM.


#178 Knasal

Knasal

    Surveyor 1

  • *****
  • Posts: 1,555
  • Joined: 15 Sep 2014
  • Loc: Wisconsin, USA

Posted 09 September 2019 - 10:25 PM

I use Naglers, typically 9T6 or 7T1 and if the seeing is good enough and the target small enough, a 5T6 or 3-6 TV zoom for the most distant targets at 2 to 3 billion light years.  I could probably use an 8mm...there are times when going from the 9 to the 7 is a little beyond what conditions really support. 

Can you tell us the magnification you get with the 9T6 and 7T1 in your 20”, and whether you use a TV Paracor with them?

 

What would Mag be with the above EPs if that’s the case?

 

Thanks, just trying to compare with my setup.

 

Kev



#179 Redbetter

Redbetter

    Cosmos

  • *****
  • Posts: 9,130
  • Joined: 16 Feb 2016
  • Loc: Central Valley, CA

Posted 10 September 2019 - 12:32 AM

With my scope the mags are: 9mm = 278x, 7mm = 357x, 5mm = 500x.  6mm (in zoom) = 417x. 

 

I don't have a Paracorr. 

 

I use 278x most of the time for galaxies since my dark sites will typically support that.  When they don't I will use the 11 for 227x, or even a 13 for 192x if it is particularly bad (the latter is usually limited to winter observing in the Valley.)

 

For the most distant galaxies and smallest cluster members I will go as high as seeing permits but 357x is a typical limit on a decent night, perhaps 500 or more during the most stable time of the year at my more stable site. 

 

When I say "when the seeing supports it" I am referring to the level of blurring/flaring/rapid focus movement that renders the smallest/dimmest galaxies nearly indistinguishable from 16, 17, or 17+ mag stars...or pairs or trios of the same.  If the seeing is several arc seconds further magnification only increases the moving blur and it is hard to distinguish a bloated dim star from a the semi-stellar core of a galaxy that is itself is perhaps 10 arc seconds across. 



#180 quazy4quasars

quazy4quasars

    Ranger 4

  • *****
  • Posts: 373
  • Joined: 12 Jul 2014
  • Loc: Northern Sierra Foothills, CA.

Posted 10 September 2019 - 11:49 AM

  I'd add that (less than ideal) seeing and LP sky glow (less than ideal transparency) both place effective limits on the usable magnification for these most distant and reddened BCGs: When faint stars become "Fuzzy Li'l Nuthins", the already really dim and very small real  FLNs (the barely visible BCG cores) begin to become mere INs -"Invisble Nuthins"; -they're never very far from that threshold. Even in a very dark sky, in great seeing, they are (those featuring AGNs excepted) close to the practical limit of visible scotopic SB contrast - For me they are, anyway- cool.gif    


Edited by quazy4quasars, 10 September 2019 - 01:23 PM.


#181 NGC7702

NGC7702

    Lift Off

  • -----
  • Posts: 7
  • Joined: 01 Feb 2017

Posted 02 October 2019 - 08:37 PM

Hi All,

In terms of "normal" galaxies (ie not QSOs) a possible target for southern hemisphere observers with very large telescopes is ESO 146-8 near the Indus/Tucana border. I haven't had a crack at it as yet but will do so in the next couple of months with my 25" f/5. It has a nice set of nearby marker stars that should make identification of the precise location pretty easy. My observing site in central NSW, Australia typically has SQM-L readings near zenith of about 21.7 - 21.8 this time of year on moonless nights. Even so, I think it would be pushing the edge of the envelope.

ESO 146-8 has a B mag of +16.7  coupled with V(km/s) +48400 [~] / z(~) 0.176884 [~] implying a look-back time in the order of 2.2 Gyr (assuming a Hubble constant of 71.5 kms/sec/Mpc).

http://simbad.u-stra...ubmit=submit id

It is found only a couple of high-power fields away from the somewhat brighter but still very distant ESO 146-5 (I have seen ESO 146-5 in my 18" f/4.9) that has a B mag of 15.75, V(km/s) +28711 [99] / z(~) 0.10083 [0.00033] and therefore resides probably about the 1.3 Gyr look-back time.

http://simbad.u-stra...ubmit=submit id

 

 

Best,

L.

Hi All,

 

I can add that I was successful in observing ESO 146-8  on 25th September 2019 with my 63.5cm f/5 at x260 and x347. The observing note follows:

x347: Very to extremely faint and tiny -- probably no more than 15" diameter if that spot of V/LSB ephemeral mist with no visible internal brightening. No structure visible. Can be glimpsed with A/V every several seconds. Must pinpoint location exactly. Not visible at x196, detectable but less certain at x260.

 

I might also add that following on upon that successful sighting, several days later using a friend's 50cm f/5 at x277 (different, but similar quality observing site) we were able to detect it at x277 at least several times per minute.

I had previously observed ESO 146-5 (which is one of the, if not the most massive galaxy in the "local" Universe) with my own 46cm f/4.9 at x185. I observed it again and the note follows:

x185: Very small to tiny and very faint spot of mist about 15" diameter 1.5' SE of a magnitude 12.5 star than can be just held continuously using A/V. Consistent S.B halo, no other visible structure.

 

ESO 146-5 weighs in about 30 trillion solar masses and is the dominant galaxy in AGC 3827.

Best,

L.


  • quazy4quasars and Luca Brasi like this

#182 quazy4quasars

quazy4quasars

    Ranger 4

  • *****
  • Posts: 373
  • Joined: 12 Jul 2014
  • Loc: Northern Sierra Foothills, CA.

Posted 02 October 2019 - 10:51 PM

Hi All,

 

I can add that I was successful in observing ESO 146-8  on 25th September 2019 with my 63.5cm f/5 at x260 and x347. The observing note follows:

x347: Very to extremely faint and tiny -- probably no more than 15" diameter if that spot of V/LSB ephemeral mist with no visible internal brightening. No structure visible. Can be glimpsed with A/V every several seconds. Must pinpoint location exactly. Not visible at x196, detectable but less certain at x260.

 

I might also add that following on upon that successful sighting, several days later using a friend's 50cm f/5 at x277 (different, but similar quality observing site) we were able to detect it at x277 at least several times per minute.

I had previously observed ESO 146-5 (which is one of the, if not the most massive galaxy in the "local" Universe) with my own 46cm f/4.9 at x185. I observed it again and the note follows:

x185: Very small to tiny and very faint spot of mist about 15" diameter 1.5' SE of a magnitude 12.5 star than can be just held continuously using A/V. Consistent S.B halo, no other visible structure.

 

ESO 146-5 weighs in about 30 trillion solar masses and is the dominant galaxy in AGC 3827.

Best,

L.

I wish, that for just even one night per month, the Earth really were flat. Then we all could see those behemoths.

 

I'd give my eye teeth to see them in my big scopes!  But- the eye teeth market is saturated.  A3827, A2744 etc; and some great QSOs, not to mention all the glories of the Southernmost reaches of the Milky Way and the 3 best Globulars in the whole sky!  Darn Spherical Earth!   At least we have the internet for the pics. But you're there, mate. Lucky Dog!  How I envy you.


Edited by quazy4quasars, 02 October 2019 - 10:52 PM.

  • NGC7702 likes this

#183 sgottlieb

sgottlieb

    Apollo

  • *****
  • Posts: 1,459
  • Joined: 22 Jul 2007
  • Loc: SF Bay area

Posted 03 October 2019 - 06:35 PM

  There were a number of quite distant Galaxies (Super Spirals and BCGs) that I didn't manage to attempt this Spring due to weather and my dark sites being snowed in;  All are low surface brightness and generally they need to be attempted near their culmination, under decently dark skies: Now many are falling into the West; and the Summer -the inner- Milky Way is rising to its late Summer prominence. 

   

  For those who are smitten with the Deep Galaxy bug and want to get a jump on the ones on the other side of the Milky Way, through the Southern Window, I offer this small selection: Some of these are 10-12" and up, others are more like 18-20" class, but dark sky is the main limiter of course:  These are among the most likely visually detectable at such distance; complied from multiple catalogs. You can check CDS, NED, HyperLeda for details:  

 

PGC 188874

PGC 97447
PGC 1480586
PGC 1013135
PGC 71834
PGC 1008418
PGC 97456

 

Fall is coming...Happy hunting!

I thought I would follow up on a few of your suggestions at last week's central California star party (CalStar) at Lake San Antonio.  Both transparency (SQM 21.4-21.5) and seeing were off from previous years, though dark enough to easily surpass the 1 billion l.y. threshold with my 24" Starstructure.

 

PGC 97456 in Aquarius and PGC 71834 in Pisces have similar redshifts (z = .083 and .084) and light-travel times of 1.1 billion years.  PGC 97456 is the BCG (brightest cluster galaxy) in the Abell cluster 2448 and PGC 71834 is the BCG in the SDSS cluster [GMB2011] 1462.  Although their listed magnitudes are similar (about V = 14.5), I found PGC 97456 more prominent (visible continuously), despite being nearly 10° further south.  But I logged PGC 71834 as larger (~0.3' diameter) than 97456 (~0.2' diameter).

 

LEDA 188874 is also in Aquarius and well placed this time of year.  This one is over a magnitude fainter (B mag close to 17) and quite small.  At z = .137, the light-travel time is ~1.8 billion years.  It only popped intermittently for me, though the galaxy is partially "masked" by a mag 15.7 star only 20" NE.  The position was pinpointed using a nearby galaxy (CGCG 375-048) 8' E and 9th magnitude HD 204738, a similar distance NE.  LEDA 188874 forms the southwest vertex of an equilateral triangle with these two objects.

 

As far as distant galaxies, I also took a look at IC 1757 = LEDA 174458 in Cetus, which was discovered visually by Barnard, probably with the 36-inch refractor at Lick.  Its redshift is similar to the first two, so tops the 1 billion year threshold.  This galaxy is just 1.5' east of IC 1756 = UGC 1429, a faint (but brighter) edge-on that lies in the foreground.  The SDSS image of the pair is here.  HyperLEDA and SIMBAD don't recognize the IC designation, but NED does.


  • lambdaw098, quazy4quasars and NGC7702 like this

#184 Luca Brasi

Luca Brasi

    Ranger 4

  • *****
  • topic starter
  • Posts: 333
  • Joined: 20 Jul 2017

Posted 25 January 2020 - 01:40 PM

So I'm gearing up for my yearly trip to Utah and Bortle 1 skies!  I've been thinking about purchasing a TV 11mm Plossl for the faintest of the fuzzys.  I use 100 degree eyepieces and a Coma Corrector, and Ive only used cheap plossls. 

 

Do you think a premium Plossl without a Coma Corrector would noticablely improve light transmission over my current setup?



#185 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 46,327
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 25 January 2020 - 02:07 PM

So I'm gearing up for my yearly trip to Utah and Bortle 1 skies!  I've been thinking about purchasing a TV 11mm Plossl for the faintest of the fuzzys.  I use 100 degree eyepieces and a Coma Corrector, and Ive only used cheap plossls. 

 

Do you think a premium Plossl without a Coma Corrector would noticablely improve light transmission over my current setup?

No.  You might go from 94% to 98%, about a 0.03 magnitude improvement.

That is likely less than the difference in the sky from moment to moment.

My last time out I was looking at a galaxy somewhere in the middle 15th magnitude range with an Ethos eyepiece

and I popped in a Delite (which has really insanely good contrast) to see if I could see it better.

Nope.  And the extra need for constant nudging drove me nuts, so I went back to the Ethos.

And your scope has an even longer focal length than mine.

The gain in light grasp with a simpler eyepiece, which is what is needed, isn't sufficient enough to help at all.

A sky with high transparency is what matters.  A large aperture scope is what matters.  Eyes very sensitive to light are what matter.

Concentrate on maintaining the best night vision you can to see deeper.

 

--don't use any lighting of any kind.  Cover all red led lights with tape.

--don't look at the night sky with your observing eye.

--block all peripheral light at the eyepiece, with hands, hood, lightshield, whatever.  Since you own the 9mm 120°, you're already used to doing this.

--look at a black cloth on the ground until you can see wrinkles in it, then move to the eyepiece immediately

--be at least 15 minutes after looking at the sky or using a light of any kind.

--if you use DSCs, turn off the screen

--use the eyepiece with the rubber flipped up

By doing all that, you can gain a half magnitude.  That's like having an eyepiece with only a 63% transmission versus a 100% transmission, a situation that doesn't exist.


Edited by Starman1, 25 January 2020 - 02:07 PM.

  • Mark SW, starzonesteve, RazvanUnderStars and 2 others like this

#186 Luca Brasi

Luca Brasi

    Ranger 4

  • *****
  • topic starter
  • Posts: 333
  • Joined: 20 Jul 2017

Posted 26 January 2020 - 03:36 PM

Thats some great info.  I will need to try the black sheet method next time.

 

I've been a bit bothered by the glass sandwich which is my 9mm 120 degree.  It's an amazing eyepiece for the Veil and Orion Nebulas, and galaxy clusters.  But I was a bit dismayed by it's performance on Bodes Galaxy.  I could barely see it's arms with the 9mm 100, but no arms were visible in the 120.

 

I ended up selling the 100 degree and keeping the 120 (which has become my most used eyepiece)!  Part of me wonders if it is the lack of field stop or the extra glass that made the difference??? 

 

I decided to get the 11mm TV Plossl.  Mainly because I'm a gear head and would like to look through one of these legendary eyepieces!  



#187 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 46,327
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 26 January 2020 - 06:35 PM

Thats some great info.  I will need to try the black sheet method next time.

 

I've been a bit bothered by the glass sandwich which is my 9mm 120 degree.  It's an amazing eyepiece for the Veil and Orion Nebulas, and galaxy clusters.  But I was a bit dismayed by it's performance on Bodes Galaxy.  I could barely see it's arms with the 9mm 100, but no arms were visible in the 120.

 

I ended up selling the 100 degree and keeping the 120 (which has become my most used eyepiece)!  Part of me wonders if it is the lack of field stop or the extra glass that made the difference??? 

 

I decided to get the 11mm TV Plossl.  Mainly because I'm a gear head and would like to look through one of these legendary eyepieces!  

I've not measured the transmission of the 9mm 120°, but I see the same thing you do--transmission seems to be lower than other hyper-wide eyepieces.

I suspect it's the 12 lenses in 8 groups (16 air-to-glass surfaces), coupled with average multi-coatings and a few percent loss simply due to the number of inches of glass passed through.


  • Luca Brasi likes this

#188 Pcbessa

Pcbessa

    Ranger 4

  • -----
  • Posts: 386
  • Joined: 26 Jan 2019
  • Loc: Forres, NE Scotland, UK

Posted 28 January 2020 - 04:15 AM

I am now back into galaxy season.

I haven´t seen that many galaxies during autumn months as I was delighted testing my new 10" Dob across the summer skies.

 

Yesterday I remembered to had a new look into the Andromeda Parachute quasar, at 11 Billion light years!

And I am please to say that I confirmed indeed my observations from last year, using my 10" Dob.

 

The quasar is still very faint and only seen with averted vision at times, and only after adapted night vision (after 10min or so).

300x makes the observation possible. At 600x it wasnt visible as the quality of image degraded seriously. Less than 300x, and the quasar becomes very difficult to observe.

 

The quasar is quite tightly close to the magnitude 12 star (seems to be around 10-20") which makes the observation hard due to its glare. I could also see other 3 faint stars (mag 14.5-15) near this magnitude 12 star. For this quasar its absolutely impossible to resolve anything more than a very faint stellar point with my 10". Already spotting it is hard and the proximity to the bright star adds to the challenge.

 

The night had acceptable transparency but far from perfect. I was in my rural Bortle 4 place, so it must be easier from the Bortle 2 skies I have half an hour from here. I also started exploring Abel 426 in Perseu again. I saw more galaxies there, but overall its difficult to see more than 10 or 15. Galaxies fainter than magnitude 14 were quite hard to spot.

 

Next plan is to explore the cluster in Cancer.


Edited by Pcbessa, 28 January 2020 - 04:16 AM.


#189 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 46,327
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 28 January 2020 - 11:24 AM

I am now back into galaxy season.

I haven´t seen that many galaxies during autumn months as I was delighted testing my new 10" Dob across the summer skies.

 

Yesterday I remembered to had a new look into the Andromeda Parachute quasar, at 11 Billion light years!

And I am please to say that I confirmed indeed my observations from last year, using my 10" Dob.

 

The quasar is still very faint and only seen with averted vision at times, and only after adapted night vision (after 10min or so).

300x makes the observation possible. At 600x it wasnt visible as the quality of image degraded seriously. Less than 300x, and the quasar becomes very difficult to observe.

 

The quasar is quite tightly close to the magnitude 12 star (seems to be around 10-20") which makes the observation hard due to its glare. I could also see other 3 faint stars (mag 14.5-15) near this magnitude 12 star. For this quasar its absolutely impossible to resolve anything more than a very faint stellar point with my 10". Already spotting it is hard and the proximity to the bright star adds to the challenge.

 

The night had acceptable transparency but far from perfect. I was in my rural Bortle 4 place, so it must be easier from the Bortle 2 skies I have half an hour from here. I also started exploring Abel 426 in Perseus again. I saw more galaxies there, but overall its difficult to see more than 10 or 15. Galaxies fainter than magnitude 14 were quite hard to spot.

 

Next plan is to explore the cluster in Cancer.

Finder charts:

http://www.faintfuzz...a Parachute.pdf

The combined brightness with the lensed galaxy is about red mag.14.4.  Green magnitude 14.63, V magnitude 14.5-14.8 (estimates)

Here is a thread with data:   

https://www.cloudyni...eep-sky-hounds/

Much info in that thread.

If you weren't seeing galaxies fainter than 14, it's very lucky you could see the lensed quasar.  It's due to its "stellar" size.

Years of observing show me that if a galaxy has any size at all, it'll have to be 1-2 magnitudes brighter than a star to be visible.  My stellar limit is close to 2 magnitudes fainter than my galaxy limit.

Quasars are a different beast, however.  They are much easier to see at cosmological distances.


Edited by Starman1, 28 January 2020 - 11:26 AM.


#190 Pcbessa

Pcbessa

    Ranger 4

  • -----
  • Posts: 386
  • Joined: 26 Jan 2019
  • Loc: Forres, NE Scotland, UK

Posted 28 January 2020 - 02:31 PM

Yes, to me, galaxies seem comparable to stars that are 1-1.5 magnitudes fainter

 

With my 10":

Galaxies:
Mag12.5 slightly faint, seen easily and most times with averted vision
Mag13 faint, still easy, seen most times with averted vision
Mag13.5 quite faint, popping up on and off with averted vision. Examples include some of the brighter members of Perseu A cluster.
Mag14 very faint, seen only occasionally with averted vision
Mag14.5 mostly invisible, seen rarely with averted vision. IC1101 is an example (but under Bortle 2 skies, I have seen this galaxy popping on and off, about half of the times with indirect vision)
Mag15.0-15.4 faintest galaxies I ever saw. Like the brightest 3 in Abell 2065 Corona cluster. Very hard, seen only under excellent Bortle 2 skies and well adapted night vision

 

Stars
Mag12.5 easily visible, somehow bright
Mag13 easily visible, not that bright
Mag13.5 slightly faint, and seen better with averted vision than directly
Mag14 faint, seen always and easily with averted vision
Mag14.5 quite faint, popping on and off with averted vision
Mag15 very faint, seen only sometimes with averted vision (but I had occasions where I hold constantly in sight mag15 stars, in Bortle 2)
Mag16 mostly invisible, seen rarely with averted vision.
Mag16.0-16.3 faintest stars I ever saw. In NGC206 star cloud in M31 (but these are casual observations, I haven´t try to activity push this my limit)

 

As Andromeda parachute quasar is seen as a 14.4 stellar point, it is within the limits of a 10" under good dark skies.

The challenge is the need to employ high power (300x) in order to darker the sky and increase the separation from the mag12 star.

Because of the proximity to the star, it looks about 0.5 magnitude fainter than it actually is, behaving like a mag15 star.


Edited by Pcbessa, 28 January 2020 - 03:50 PM.

  • Astrojedi and Luca Brasi like this

#191 Astrojedi

Astrojedi

    Aurora

  • *****
  • Posts: 4,506
  • Joined: 27 May 2015
  • Loc: SoCal

Posted 28 January 2020 - 02:39 PM

With my 10":

Galaxies:
Mag12.5 slightly faint, easy, seen mostly with averted vision
Mag13 faint, still easy, seen most times with averted vision
Mag13.5 quite faint, popping up on and off with averted vision
Mag14 very faint, seen only occasionally with averted vision
Mag14.5 mostly invisible, seen rarely with averted vision
Mag15 faintest galaxies I ever saw. Like some in Abell 2065. Very hard, seen only under excellent skies and adapted night vision

Stars
Mag12.5 easily visible, somehow bright
Mag13 easily visible, not that bright
Mag13.5 slightly faint, and seen better with averted vision than directly
Mag14 faint, seen always and easily with averted vision
Mag14.5 quite faint, seen always with averted vision
Mag15 very faint, popping on/off sometimes with averted vision
Mag16 mostly invisible, seen rarely with averted vision
Mag16.3 faintest stars I ever saw

A very good summary. Pretty much mirrors (no pun intended) my experience with my 10" Dob from my SQM 21.6 club dark site.



#192 Pcbessa

Pcbessa

    Ranger 4

  • -----
  • Posts: 386
  • Joined: 26 Jan 2019
  • Loc: Forres, NE Scotland, UK

Posted 28 January 2020 - 03:49 PM

Quazy4quasars, with a 10", any other ideas for other interesting distant quasar targets?

 

I thought of trying B1422+231 in Bootes but I do not have a star chart for it.

How about Einstein Cross or the Double Quasar, can these be spotted as a single unresolved stellar point at the threshold of visibility with a 10" aperture? If they are magnitude 16 or 16.5, they are theoretically visible, especially if I drive to a Bortle 1 spot, but anything fainter than that, and they would be out of question for my Dob. My sense is that they are far beyond the reach of my scope.

 

Last spring, Abell 2065 in Corona (4 galaxies seen), PGC46931 in Ursa Major (Abell 1738), PGC37477 in Leo (Abell 1413) and PGC23645 in Lynx (Abell 655), were my furthest and faintest galaxies seen, at 1.5 or 1.8 billion light years.

 

But I also enjoy staying within 500 million light years, as galaxies are much brighter. 

Currently I have been exploring Perseu A (counting now 19 galaxies seen)

Last year I have seen also: Leo A (28 galaxies seen), Abell 262 (3 galaxies) and Abell 347 (2 galaxies) in Andromeda, Abell 779 (1 galaxy seen) in Lynx, Coma cluster Abell 1656 (20 galaxies seen), Abell 2197  (5 galaxies), Abell 2067 and Abell 2162 (2 galaxies) in Corona Borealis, Abell 2151 (5 galaxies) and Abell 2199 (2 galaxies) in Hercules

 

Wishlist: Abell 671 (600M ly) and Abell 690 (1 B ly) in Cancer, Abell 1689 Virgo (2 B ly), Abell 2061 in Corona Borealis, Abell 2152 in Hercules, Abell 2147 in Serpens.

Similar threads:

https://www.cloudyni...y-with-12-inch/

https://www.cloudyni...sible-in/page-2

https://www.cloudyni...xy#entry9902190

https://www.cloudyni...xy#entry9685868

https://www.cloudyni...tars-what-else/

http://www.faintfuzz...Clusters v1.pdf


Edited by Pcbessa, 28 January 2020 - 04:36 PM.

  • Luca Brasi likes this

#193 Pcbessa

Pcbessa

    Ranger 4

  • -----
  • Posts: 386
  • Joined: 26 Jan 2019
  • Loc: Forres, NE Scotland, UK

Posted 30 January 2020 - 12:23 PM

I was napping the main galaxy clusters within 1-2 billion light years, and came with a few questions:

Some of the nearest clusters, within 200 M ly, and ordered by distance, are: the Virgo cluster (where we are located and in which M87 is centre), Fornax (invisible from the UK but apparently with many galaxies), Eridanus (a few bright galaxies around mag 10-11 but i haven't explored it), A1060 Hydra (supposedly bright, but I haven't seen this one as it lies quite far south), and the Norma cluster A3627, to where our Virgo cluster is moving towards (named the Great attractor). Anyone has seen any member from this last one? It is invisible from where I live. But being near the galactic plane.makes it probably much fainter.

At 300 M ly, the nearest big filament of clusters is the Great Wall formed by Leo A1367, the Coma cluster, and the Hercules clusters. All can be seen as clusters on my 10", though the Hercules ones seem a bit further away and fainter at almost 500M ly.. What links the Leo-Coma to the Hercules clusters surprises me as I am not aware of any clusters ir galaxies in between. Any idea?

Another nearer supercluster is Perseu-Pisces and includes the bright Perseu cluster and the nearby A262 and A347 (all visible in a 10"). But does this supercluster really extends into Pisces?

Peganus also has a multitude of clusters within 100 M Ly, but there seems to be little information about to which supercluster that they belong, or their distance.

Leo supercluster, at 500 M ly, comprises several clysters located actually in Ursa Major, like A1228, A1314, and A1185, which are relatively bright members, at mag 13. Plenty of information on these ones.

Finally Ophiucus supercluster at 500 Ly. Having been discovered recently I doubt it would be seen by any small telescope. The Milky way probably obscures the view, just like for the Norma cluster. Anyone knows anything about this one?

Stepping towards the 1 Billion light years barrier, there is the Corona supercluster (well known and brightest galaxies in A2065 making into magnitude 14.5), the Ursa Major supercluster ( I haven't tried these but the best target is A1318 near NGC3737), and the Sextans supercluster and the Pegasus-Cetus supercluster. Anyone observed any of these clusters other than the Corona Borealis cluster (which is week documented). There is a shortage of location information or the magnitude, for these clusters. All are excellent candidates for observing other "bright" magnitude 14 galaxies, similar to IC1101.

At 2billion light years, , we find only a few known superclusters. Othe than the obscure clusters already mentioned here, like A655 in Lynx or A1413 in Ursa Major (of which the brightest member shines at mag 15), the only promising clyster I found were the Draco and the Capricorn superclusters.. But I haven't found any information on individual galaxies, magnitude, or location charts, for these.
  • sgottlieb likes this

#194 quazy4quasars

quazy4quasars

    Ranger 4

  • *****
  • Posts: 373
  • Joined: 12 Jul 2014
  • Loc: Northern Sierra Foothills, CA.

Posted 30 January 2020 - 12:49 PM

Regarding the post about QSOs:

 

imgcutCAPWPZL8.jpg https://www.cloudyni...us#entry9623947

 

I generate field images using Wilisky and then email them to my ipad for use in the field.  Above is an SDSS image of the field of B1422+231

 

It is worth mentioning that while a few elusive QSO targets benefit from associated and nearby brighter asterisms that aid in targeting.  Using a 10", you are more limited in having generally fewer clear reference points for determining the exact QSO position, than a scope of say ~16" and up... A good example of this problem is B1422+231, which is found within a large, loose web of eight or nine variously faint (<15) stellar sources, only a couple of which are a bit less inconspicuous in 10" than B1422+231 itself.  Whether these so few barely visible stars would provide a clear indication of the position of the lensed QSO- as opposed to the other AV inklings in the area, is doubtful, but, there's no harm in trying.  At least with "the Parachute", there is no doubt about exactly where the QSO is, as you have that 12 mag star nearly on top of it...  


Edited by quazy4quasars, 30 January 2020 - 09:07 PM.

  • Ptarmigan likes this

#195 sgottlieb

sgottlieb

    Apollo

  • *****
  • Posts: 1,459
  • Joined: 22 Jul 2007
  • Loc: SF Bay area

Posted 30 January 2020 - 05:02 PM

Stepping towards the 1 Billion light years barrier, there is the Corona supercluster (well known and brightest galaxies in A2065 making into magnitude 14.5), the Ursa Major supercluster ( I haven't tried these but the best target is A1318 near NGC3737), and the Sextans supercluster and the Pegasus-Cetus supercluster. Anyone observed any of these clusters other than the Corona Borealis cluster (which is week documented). There is a shortage of location information or the magnitude, for these clusters. All are excellent candidates for observing other "bright" magnitude 14 galaxies, similar to IC1101.

The Ursa Major Supercluster includes at least 10 Abell clusters with some, such as as A1377, "only" 700 million l.y (z = .051).   Unfortunately, a 5th magnitude star (HD 102328) is parked 6' south of this cluster's center!  I took a look at it 10 years back in my 18" and logged a half-dozen members.  The brightest two were MCG +09-19-190 (PGC 36805) and MCG +09-19-182 (PGC 36774), both V ≈ 14.7.  Of course, it's key to keep the bright star off the edge of the field.

 

Abell 1318, which you mentioned, is slightly more distant at z = .058, but it’s a tricky field.  A foreground galaxy group, including NGC 3737 (which you mentioned), NGC 3759, MCG +09-19-126 and others, are mixed in the field.   NGC 3737, for example, is at z = .019, only ⅓ the distance of the Abell cluster.  Coincidentally, a 5.6-magnitude star (HD 100615) is just off the southwest side of this cluster!

 

Another UMa Supercluster member is A1452 (z = .063 or about 850 million l.y.).  It's located 1.6° southeast of NGC 3953 or 1° northeast of NGC 4026.  This cluster contains HCG 60, which may be the core of the cluster.  The brightest member HCG 60A = MCG +09-20-071, is also about V = 14.8.  The other Hickson members are at least a magnitude fainter, but another good cluster target is MCG +09-20-074 = PGC 38092 (seemed similar to me as HCG 60A).

 

Unfortunately, none of the clusters I mentioned has a superluminous cD member that really outshines the other galaxies, as in the case of IC 1101 and others. 


Edited by sgottlieb, 30 January 2020 - 05:52 PM.

  • Ptarmigan, timokarhula, KidOrion and 1 other like this

#196 Pcbessa

Pcbessa

    Ranger 4

  • -----
  • Posts: 386
  • Joined: 26 Jan 2019
  • Loc: Forres, NE Scotland, UK

Posted 31 January 2020 - 06:09 PM

Yesterday I observed Abell 539 well located just west of Bellatrix. Who would say the treasures that Orion hides?

It's a distant clyster, supposedly at 300 million light years but it looks a lot like A2065, rich in a small area of 10- 20 arcminutes. Galaxies are very faint and tiny, at mag 14.5 upwards. Managed with extreme difficulty to log 5 members. But some galaxies only popped occasionally into view. UGC3274 and Mac 0516+0626A were the easiest to spot

Anyone has seen this cluster?
  • Ptarmigan likes this

#197 sgottlieb

sgottlieb

    Apollo

  • *****
  • Posts: 1,459
  • Joined: 22 Jul 2007
  • Loc: SF Bay area

Posted 01 February 2020 - 06:45 PM

I'm surprised Abell 539 isn't better known, just 2° degrees west of Bellatrix.  You're certainly pushing the boundaries for a 10-inch scope!

 

I first observed this cluster back in 1989 and again in 2006 with my 18".  I logged 9 members in the central region including splitting the UGC 3274 chain into two galaxies.  My last observation (5 years back) was through Jimi Lowrey's 48" and the chain (UGC 3274 = VV 161) resolved into 5 tiny galaxies crammed into 1'!   A total of 13 galaxies were visible in a 5' circle.


  • Ptarmigan likes this

#198 Pcbessa

Pcbessa

    Ranger 4

  • -----
  • Posts: 386
  • Joined: 26 Jan 2019
  • Loc: Forres, NE Scotland, UK

Posted 02 February 2020 - 09:41 AM

It´s a fantastic cluster, isn´t it?

 

I had the feeling that Abell 539 in Orion, just west of Bellatrix, might be much further out than the indicated 300 million years. My sense is that this cluster is more like 600-1 billion light years away, because the cluster looks rather faint, galaxies are tiny, and clustered in a very small area.

 

Another ignored Abell cluster is Abell 779 in Lynx, which I explored yesterday. This one is a great target for a 8 or 10 inch Dob. And I was also surprised for it not being better known. It seems similarly easy to the Leo and Perseu clusters, perhaps a bit fainter. It is also located at around 300 million light years away.  t has several "bright" NGC galaxies (all between mag 12 and 14). I quickly spotted the 11 galaxies listed in the chart I printed, and a couple suspected fainter ones, sadly I did not listed the PGC galaxies on it, and by then it was 2am and I was tired. But Lynx was high up, sky was very dark, as the moon had set by then. Galaxy season is just starting!

 

 

I'm surprised Abell 539 isn't better known, just 2° degrees west of Bellatrix.  You're certainly pushing the boundaries for a 10-inch scope!

 

I first observed this cluster back in 1989 and again in 2006 with my 18".  I logged 9 members in the central region including splitting the UGC 3274 chain into two galaxies.  My last observation (5 years back) was through Jimi Lowrey's 48" and the chain (UGC 3274 = VV 161) resolved into 5 tiny galaxies crammed into 1'!   A total of 13 galaxies were visible in a 5' circle.



#199 Ptarmigan

Ptarmigan

    Lagopus lagopus

  • *****
  • Posts: 4,839
  • Joined: 23 Sep 2004
  • Loc: Arctic

Posted 02 February 2020 - 03:27 PM

Yesterday I observed Abell 539 well located just west of Bellatrix. Who would say the treasures that Orion hides?

It's a distant clyster, supposedly at 300 million light years but it looks a lot like A2065, rich in a small area of 10- 20 arcminutes. Galaxies are very faint and tiny, at mag 14.5 upwards. Managed with extreme difficulty to log 5 members. But some galaxies only popped occasionally into view. UGC3274 and Mac 0516+0626A were the easiest to spot

Anyone has seen this cluster?

I saw Abell 539 and also saw VV161. A two for one! cool.gif lol.gif

 

Abell 539

http://www.wro.org/s...by_Abell539.pdf



#200 Ptarmigan

Ptarmigan

    Lagopus lagopus

  • *****
  • Posts: 4,839
  • Joined: 23 Sep 2004
  • Loc: Arctic

Posted 02 February 2020 - 03:32 PM

How about this?

 

List of the most distant astronomical objects

https://en.wikipedia...nomical_objects


  • Dave Mitsky likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: dob, dso, observing, sketching



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics