21 replies to this topic

[Cotts]

According to Sky Safari, 11.75 magnitude and a diameter of 8.0'...  Should be a relatively easy target for my 20-inch.....  Well placed near the meridian in Western Serpens.... Skies are predicted to be very clear and dry...  seeing is forecast to be "bad", 1/5 on CSC...

 

But shoulda, coulda, woulda sometimes are the enemies of success...

 

I've a hankering to bag the Palomars and the Terzans with the 20..... 

 

Anyone else seen it/them?

 

Dave

 

 

[BrentKnight]

I have not, Dave.  I'll add it to my observing list for my EAA rig though...  Sounds like a really interesting target given that it's surrounded by faint galaxies.

[Akarsh Simha]

You need very dark and transparent skies as the object is very low surface brightness. Ideally Bortle 2 or better, but perhaps you can get away with Bortle 3.

 

After many years of thinking that I had hit all the Palomar globs in my 18", I looked through my notes and realized I was missing Palomar 5. So I put it on the list earlier this year and managed to observe it in April, from the outskirts of Kanab, Utah under ~Bortle 2.5 conditions. My notes read "An extremely feeble roundish glow only detected by knowing the exact position. The glow was definitely observed in a 20mm Pentax XW."

 

I was rather exhausted, so perhaps I could've done better if I had more energy.

(20mm eyepiece on my scope gives 103x, exit pupil of 4.4mm)

[Keith Rivich]

I saw this for the first time in 2005 at TSP in 25".

 

20mm Nagler: Very faint. Easy to locate, bracketed by 3 brightish stars in a triangular shape. Once seen I could hold it with direct vision. Some stars resolved in the 9mm Nagler. 

 

Several CGCG galaxies in the area. All nearly stellar. 

[Akarsh Simha]

Regarding your larger project, I've managed to see all the Palomars in my 18", so I imagine they shouldn't be tough for you with a 20" and access to dark skies in Canada. Most of the following observations were made with from Bortle 2 or Bortle 1 (where marked as "TSP" for Texas Star Party) skies from Texas. All of them were made with my 18", most of them with a very bad coating on the mirror, so your results might actually be better.

Palomar 1 (Jan 2015): Somewhat elaborate star-hop. Seen with averted vision in a 10mm Delos (2.2mm EP, 207x). Rocking the focus enhanced the view. Observation confirmed by cross-checking precise observed position against DSS image. View best in 10mm Delos followed by 14mm Pentax (3.1mm EP, 148x). At the edge of visibility, but confirmed repeatedly. Easier than Fornax Hodge GC 1 [which I had observed earlier that night], though factor in the altitude difference.

 

Palomar 2 (Nov 2013): Surprisingly easy. Brought the asterism to the north east of the object into view, scanned the field with averted vision, and it was right there. Best view was in 10mm Delos. Only very inconspicuous hints of resolution. Much harder in a 7mm Nagler (1.5mm EP, 295x). After having seen it in the 10mm eyepiece, I was also able to see it in a 31mm Nagler (6.8mm EP, 67x).
 

Palomar 3 (Jan 2015): Very indistinct glow to one side of a star. Sensed it repeatedly at 20mm (4.4mm EP, 103x), 14mm. Asymmetric to one side of the star. Very very faint, more difficult than Holmberg I [which I had observed previously]. I consistently see the brightness more to the south than the DSS image indicates.

Palomar 4 (Apr 2012, TSP): Very faint. Could hold ~25% of the time with averted vision.

[Palomar 5 already posted above]

Palomar 6 (Apr 2012, TSP): Beautiful! Rather easy. Was viewed @ 31mm Nagler + 2x Barlow. Huge!

Palomar 7 = IC 1276 (Mar 2014): Easy for a Palomar, tough for an IC object!
 

Palomar 8 (Aug 2013): Very easy Palomar. Visible as an unresolvable patch in 31mm Nagler. Another asterism / open cluster lies South, but that is more resolved although fainter. Initially thought it to be a nebula. Somewhat better resolved in the 10mm Delos. Resists complete resolution even in 7mm Nagler. Better in 4.5mm Delos (1mm EP, 459x) under improved seeing.

Palomar 9 = NGC 6717 (Aug 2013): Very close to orangish-yellow star. Easy, bright but small. 31mm Nagler. (I have also seen this in an 8" telescope for what it's worth, but can't find the log). This is perhaps the easiest amongst Palomar globulars.

Palomar 10 (Apr 2012, TSP): "Very faint, circular glow"

Palomar 11 (Aug 2013): Easy star-hop from Kappa Aquilae. Rather faint, but "resolved" even in 31mm Nagler. After precise star-hopping, it was easily located in the field and confirmed against neighboring stars. 10mm Delos insinuates that the feeling of resolution might only be because of foreground stars. Somewhat large, faint glow with a few bright stars (presumably foreground stars) on it. DSS image seems to indicate otherwise, that the feeling of resolution is actually real and there are no real foreground stars. This is confirmed again by averted vision.

 

Palomar 12 (Aug 2013): Star-hopped from M 30 in 31mm Nagler. Was just about detectable in the 31mm Nagler. Triangular asterism conveniently "points" to the globular. 10mm Delos shows the cluster nicely, and notes that the cluster is a tad west of where the "arrow" points, which was later confirmed against DSS image. The "chain" of more prominent stars was noted in the eyepiece and checked against DSS. More sensation of resolution at 7mm, but the fainter stars are rendered invisible.

 

Palomar 13 (Oct 2013): Barely detected. Had to know exactly where to look. Held the core brightening for multiple instants in a 10mm Delos. Could not hold continuously. This is a confirmed observation, but must ideally repeat as I had to stare very hard and look for it in the exact location to see it. Tried multiple eyepieces: 10mm Delos worked best, followed by 13mm Baader Hyperion (2.9mm EP, 159x).

Palomar 14 (Jul 2014): "On a night of poor transparency, the stars in the field sported halos; however, there was a fainter star which had a more concentrated halo, comparable to the brighter stars in the field or perhaps even larger. This is the glow of Palomar 14, as confirmed later." Earlier (May 2014, TSP) from the darker skies of Texas Star Party: "20mm Pentax was useful to detect the object by condensing the core. 10mm Delos was thereafter useful. Not terribly difficult. Looks like a halo around a faint star."

Palomar 15 (May 2014, TSP): I spent ~1 hour observing this object in my 18" Obsession, a friend's 12" dob and my 6" dob. The object was visible only in the 18".  A slight brightening of the background was observed near a faint star pattern. The exact position was then confirmed against POSSII image. The object was repeatedly detected in the 18", made easier by tapping the scope, in the 20mm Pentax XW eyepiece.

Edited by Akarsh Simha, 04 June 2022 - 05:47 PM.

[Akarsh Simha]

Steve Gottlieb wrote an article in Sky & Telescope in the October 2021 issue on some of the objects from the Sagittarius Dwarf Spheroidal galaxy that was torn apart and "consumed" by the Milky Way. In that he lists several obscure and less-obscure globular clusters, including Palomar 12, which is part of one of the tidal streams of SagDEG. This article also inspired me to look at Terzan 7 which is the only Terzan I've attempted.

Terzan 7 (Oct 2021 from Okie-Tex Star Party): Not too difficult. Large, oval-shaped glow to the north of two stars. It resolves well although individual stars can't be discerned as they're too faint, i.e. it looks grainy.

There are lots of observations of Palomar, Terzan and also more obscure stuff like UKS globulars on Adventures in Deep Space:
https://www.astronom...ace/obscure.htm
https://www.astronom...ce/obscure2.htm
https://astronomy-ma...ace/palglob.htm

 

[Redbetter]

According to Sky Safari, 11.75 magnitude and a diameter of 8.0'...  Should be a relatively easy target for my 20-inch.....  Well placed near the meridian in Western Serpens.... Skies are predicted to be very clear and dry...  seeing is forecast to be "bad", 1/5 on CSC...

 

But shoulda, coulda, woulda sometimes are the enemies of success...

 

I've a hankering to bag the Palomars and the Terzans with the 20..... 

 

Anyone else seen it/them?

 

Dave

It is a good target for a 20" in dark sky.  As with most Palomars it possesses very low surface brightness.  11.75 V mag over an 8 arc minute diameter equates to an average surface brightness of 24.9 mpsas.   The central 4 arc minutes is only slightly brighter than this.  The saving grace for being certain of Palomar 5 is that it has some resolvable stars.  

 

I observed Palomar 5 early in my resumption of DSO observing back in 2016.  My notes were short and only moderately helpful:  "very sparse, very faint, ~8 stars resolved".  This was most likely at 278x.  If I revisit it, I expect to resolve more stars.  

 

A problem you will face with the Terzans is their southern declination.  Terzan 7 and 8 are not difficult in dark sky here, but at ~34 S they can pose more of a challenge.  Still, the other night I could see Terzan 7 with the 10" and it revealed a few stars as resolved in the 20".  Terzan 7 works out to 21 mpsas mean surface brightness.  (Keep in mind I am over 7 degrees south of you.)  It becomes much more difficult to resolve stars in faint globulars at such low elevations unless the seeing is excellent (and it was anything but that.)  Terzan 8 is in some ways similar, having a few resolvable stars, but of larger diameter resulting in lower mean surface brightness, 23.8 mpsas per my calcs.   

[sgottlieb]

There have been a few threads on Palomar 5 here in the past.  This one is from 2006.  Most reports are with larger scopes under good conditions and generally report just a dim glow with perhaps just a few stars resolved.  I've observed it three times with an 18" scope.  This one is from 2007 at the Bumpass Hell lot in Lassen National Park (elevation 8187 ft).

 

The best view of this low surface brightness globular was at 225x.  Pal 5 appeared as a very faint, round glow, ~3' diameter with a mag 13.5 star involved on the west of center.  I could just hold it continuously with averted vision as the surface brightness is very low and uniform with no central condensation.  A resolved 15th mag member was easily seen 1' due east of the mag 13.5 star.

 

Even in a quick look through a 48", it appeared more like a low surface brightness (resolved) Berkeley open cluster, rather than a globular.

 

Pal 5 is a large, ill-defined glow, extending ~5'-6' and situated just northwest of mag 9.0 HD 135660. A mag 13 star is superimposed off-center and ~15 mag 15-17.5 stars were resolved (depends on the limit of the halo) over a very low surface brightness hazy glow .  The outer edge of the halo wasn't clearly defined.

 

In any case, as others have indicated the integrated magnitude of V ≈ 11.8 is very misleading due to the size, concentration class (I believe XII) and overall low surface brightness.

Edited by sgottlieb, 05 June 2022 - 08:36 PM.

[Alan D. Whitman]

When I was observing Palomar globulars, mostly in the year 2000, I got twelve of them. Most were with my 16-inch f/4.5 equatorial from my backyard observatory at latitude 49.4 North in semi-arid southern interior British Columbia. I failed on Pal 14 and 15, and only suspected Pal 3.

 

Also in 2000 I used a 24-inch Cassegrain (a professional scope, a Boller and Chivens, so a delight to use) at Pine Mountain Observatory in Oregon for Pal 13 and Pal 1 after failing on both with my 16-inch (both were suspected with the 16-inch).

 

Pal 6 I got with a 17.5-inch Dob at Chaco in darkest northern New Mexico in 2002. I got Pal 4 with Chaco Observatory's 25-inch in 2003.

 

I haven't looked for any since, except for a mere suspected Pal 3 with my 16-inch in 2005.

 

Pal 5 was actually the first one that I tried, but it doesn't sound like it was a good one to start with. From my logbook for May 7, 2000: "Ser GC Pal 5  (starhopping from M5) at 261x (not seen at 174x). This is mag 11.8 and 3.2' in diameter (a third of the 7mm ortho's field). Had to put 9.0 mag star to SE just out of field, and use a hood and motion. The eastern margin of the GC gives the strongest contrast boundary. Starhopped with MSA [Millennium Star Atlas]. If I had used a detailed chart from Guide 7, I don't think that I could have confidently said that I'd seen it -- a slight amount of uncertainty in position is necessary with such an amorphous, large object to avoid the power of suggestion. My sketch of the core's position verified the next morning when checked with Guide 7.0."

 

This was a night of exceptional seeing because right after Pal 5 "I noticed that Antares at culmination (only 14.5 degrees) was twinkling far less than usual so I took a look at 174x and saw its companion as a stationary spark amongst all of the moving sparks! My estimated PA verified nicely when checked. The companion was even green for a moment."

Edited by Alan D. Whitman, 05 June 2022 - 03:38 AM.

[Akarsh Simha]

There have been a few threads on Palomar 5 here in the past.  This one is from 2006.  Most reports are with larger scopes under good conditions and generally report just a dim glow with perhaps just a few stars resolved.  I've observed it three times with an 18" scope.  This one is from 2007 at the Bumpass Hell lot in Lassen National Park (elevation 8187 ft).

 

The best view of this low surface brightness globular was at 225x.  Pal 5 appeared as a very faint, round glow, ~3' diameter with a mag 13.5 star involved on the west of center.  I could just hold it continuously with averted vision as the surface brightness is very low and uniform with no central condensation.  A resolved 15th mag member was easily seen 1' due east of the mag 13.5 star.

 

Even in a quick look through a 48", it appeared more like a low surface brightness (resolved) Berkeley open cluster, rather than a globular.

 

Pal 15 is a large, ill-defined glow, extending ~5'-6' and situated just northwest of mag 9.0 HD 135660. A mag 13 star is superimposed off-center and ~15 mag 15-17.5 stars were resolved (depends on the limit of the halo) over a very low surface brightness hazy glow .  The outer edge of the halo wasn't clearly defined.

 

In any case, as others have indicated the integrated magnitude of V ≈ 11.8 is very misleading due to the size, concentration class (I believe XII) and overall low surface brightness.

Steve, did you mean Pal 15 for the second one, or Pal 5?

[uwe_glahn]

Tough on, every time I visited it. Not as hard as Pal 14 and/or Pal 15, but still difficult.

 

See my notes at the:

 

Palomar Globular Observing Project

[Cotts]

No luck for me...  Crescent moon...(forgot about that....) 

 

Will try again..

 

Dave

[SNH]

Steve, did you mean Pal 15 for the second one, or Pal 5?

I caught that, too. He meant Pal 5 for both observations because he mentioned the same 13th-magnitude star. Normally I wouldn't point that out to him, but since he has very meticulous notes, he does like to know that sort of thing.

 

Scott

[Alan D. Whitman]

Tough on, every time I visited it. Not as hard as Pal 14 and/or Pal 15, but still difficult.

 

See my notes at the:

 

Palomar Globular Observing Project

Thanks, Uwe. Your notes with several apertures are excellent (as we expect from you).

 

Alan

[sgottlieb]

I caught that, too. He meant Pal 5 for both observations because he mentioned the same 13th-magnitude star. Normally I wouldn't point that out to him, but since he has very meticulous notes, he does like to know that sort of thing.

 

Scott

Yep, Pal 5 was intended.

[Ivan Maly]

I had a pretty good view of it in my old 16-inch a long time ago, but every time I have tried for it since, it was worse. At times I could not even see the cluster in what seemed to be respectable conditions. There are several starlike objects near the center that I saw and thought to be if not actual member stars then at least stellarings in the cluster, but checking Wikisky now, it is clear that while these objects are stars (Vm 14-17), they are no more densely grouped there than in the surrounding field.

[cloudbuster]

Very tough target. With a 16" I tried this one several times. No luck in the french Alps under good conditions, no luck in La Palma under very good conditions and finally confirmed in Namibia under an excellent sky (but with great effort).

 

Martijn

[SNH]

Very tough target. With a 16" I tried this one several times. No luck in the french Alps under good conditions, no luck in La Palma under very good conditions and finally confirmed in Namibia under an excellent sky (but with great effort).

 

Martijn

Yeah, it's not an easy one for sure. It was one of the first objects I looked at when I got my 16-inch this spring. It was actually not very hard with my 20mm/100* eyepiece yielding 105x. In fact, by knowing what it looked like in that telescope, I was able to walk over and JUST detect it in my 10-inch. Getting a really wide true field of view is important, but so is getting a decent amount of magnification. I'd suggest that it is best seen between 80x and 140x.

 

Scott

[Redbetter]

I had a pretty good view of it in my old 16-inch a long time ago, but every time I have tried for it since, it was worse. At times I could not even see the cluster in what seemed to be respectable conditions. There are several starlike objects near the center that I saw and thought to be if not actual member stars then at least stellarings in the cluster, but checking Wikisky now, it is clear that while these objects are stars (Vm 14-17), they are no more densely grouped there than in the surrounding field.

The Kuzma paper from 2015 lists coordinates for some of the member stars in the main condensation, twenty total (it then lists tidal stars.)  From checking the positions, those within the cluster correspond primarily to 15 to 18 mag stars in Wikisky.  So while there is considerable field contamination in this area, a fraction of the ones seen in images of the position are members.  Most would be a stretch for a 16" at high power, although a few should be seen. 

 

Uwe's sketch with a 16" at low magnification shows the brightest two non-member's, the 14 mag star NW of center and the 14 on the N edge.  It is the standard "forest vs trees" trade off trying to see larger low surface brightness globulars:  low power for the faint haze if the sky is dark enough, or high power to try to resolve some stars?   Each has its merits and application, getting both is tough. 

 

There is a 16.5 V mag galaxy (2MASX J15160607-0009492) in the SSE section near one of the 16.5 member stars (with another 16.5 non-member between).  The galaxy is at roughly 1.5 billion light years.  I have not tried for that one or the ~1.75 billion light year galaxy, PGC 184937 to the NNE of the cluster, roughly 15.6 V mag.  A 16.2 V mag galaxy, CGCG 21-059, is NW of the cluster beyond the 10.6 mag star.  There are others, although most are beyond 17 V mag.  One that is to the ENE of the cluster some distance, and about 16 V mag, is PGC 165662.   

[BrentKnight]

I took a first stab at this one last evening.  SQM-L: 19.50 with my C8.  I can normally hit 17m, but this particular session I think was closer to 15m or so.  I got no hint of a hazy glow and only some of the brighter stars (field and a few members?).  This capture was only 26 minutes, so I'll try for at least double that the next time.

 

 

 

Aladin shows more than 10 small, faint galaxies in the field.  Like Redbetter says though, they are all below about 15.5m.

[Redbetter]

Last night, 6/24/22 I had only fair transparency (a bit of smoke haze at ground level), 21.4 mpsas, and poor to average seeing.  I got around to Palomar 5 rather late, which didn't help as it was drifting lower toward a brighter part of the sky.  At 156x the globular was a large but very weak haze filling much of the space between a 9 and 10+ mag star.  A few 14 and 15/16 mag stars were seen within.

 

278x to 357x was used to resolve stars within down to around 17 mag.  Seeing wouldn't allow me to go deeper.  Several of these are known actual members of the cluster (I had a few marked with asterisks, but not all of the ones seen), others are field stars.  I targeted one galaxy within the bounds of the cluster, but at 16.5+ V mag it was only marginally seen.  2MASX J1516067-0009492 was on a line just NW of two 16+ mag stars (one a cluster member).  I couldn't hold the galaxy and the stars simultaneously, but I could see indications of something beyond the stars frequently.  Unfortunately, I couldn't hold the galaxy by itself, even though something was consistently though intermittently detected there.

 

More readily seen was CGCG 21-59 which was between 15.4 and 14.6 mag stars NW of the 10+ mag star that bracketed Palomar 5.  Its photometry suggests it is only 16.2+ mag.  PGC 165662 was marginally detected, slightly better than the 2MASX galaxy.  I started too late on PGC 184937 to detect it.  

[gnowellsct]

According to Sky Safari, 11.75 magnitude and a diameter of 8.0'...  Should be a relatively easy target for my 20-inch.....  Well placed near the meridian in Western Serpens.... Skies are predicted to be very clear and dry...  seeing is forecast to be "bad", 1/5 on CSC...

 

But shoulda, coulda, woulda sometimes are the enemies of success...

 

I've a hankering to bag the Palomars and the Terzans with the 20..... 

 

Anyone else seen it/them?

 

Dave

try Pal 14