Have any of you logged Haute Province 1 (Oph) and/or Tonantzinlia 2 (Sco)? I searched IIS and CN and didn't find any reports. I'm writing an article about them and would like to know whether anyone else has seen them & how they appeared. You can locate them in Uranometria II p. 376. HP 1 is RA 17 31 05, Dec –29 58 54. Ton 2 aka ESO 333-SC16 is RA 17 32 44, Dec -38 31 20. Thanks, =Dana in S Africa
HP 1 is the "easier" of the two and we have observed it from a dark sky site some
four hours west of Sydney in a 20". It's only a little more than 2 arc minutes across and
not easy to spot in the glow and myriad of field stars in Ophiuchus.
Your Ton 2 position from UA is one that is commonly in error.
On Argo Navis we have it at 17:36:10.5 -38:33:12 J2000.0
Your position is over 40 arc minutes away.
It is about 3.4 arc minutes across and again challenging against the Milky Way
in Scorpius with some brighter field stars in front of t. A brighter star nearby does
not help.
*Blush* on the coordintes, *Cheers* on the sighting
06/05/2013:
Thanks, Gary. I should've double-checked on WikiSky re the coordinates. I don't have ArgoNavis, my equip't is very limited. I've confirmed both objects on five separate nights in the recent dark-moon cycle, and HP1 once last year. The seeing/transparency minimum criterion I use for validating an HP 1 sighting is whether I can resolve 15-20 stars at the limit of seeing in nearby NGC 6256 Sco using a 180mm Mak. The 15 to 20 don't appear all in one glimpse but rather shimmer individually in and out of the dim glow, perhaps 8 to 10 at any one moment.
If the air passes that test, HP 1's whitish core glow is easily detected 1/2 the time on my 150 Mak 'finder', about 75% of the time in a 180mm, and 80% of the time using the 200mm. It's a very seeing-dependent object, located using a small circlet of 13 - 14 mag stars in a prolate circle reminiscent of the Pisces circlet. The cluster requires magnification, 225x to 300x. HP 1 has an exceptionally concentrated core, luminosity half-light radius at 1.5 arcmins with total photometrically verified diameter 8.1 arcmins dia. This is an odd core concentration for a post-core-collapse cluster. It points to recombinant binary formation from very close encounters in the core during the full-collapse phase.
HP 1 has received a bit of recent attention in the professional papers due to its location as the nearest GC to the bulge center and number of stars in the blue horizontal branch pointing to a 2nd generation origin. Hence it is unusually metals-rich >12 Gyr old cluster, [Fe/H] -1.61 and high Mg - Al ratios. A number of its 2nd gen stars evolved using the Na-Mg-Al process subsequent to the C-N-O cycle; the higher metals content ends in very thin stellar envelopes with 20,000 K surface temps on the far left end of the HB blue branch. Astronomer's can’t quite figure out why this happened. It appears to be an Na-rich, Mg-poor cluster, hence the recent interest. HP 1 also is unusual in acquiring bulge stars through tidal truncation on its front end as it plows through the bulge medium ~64 kms faster than the mean bulge rotational velocity at that radius, while losing trailing stars back into the bulge at about the same rate. IOW, it remains at ≈ constant mass while accreting and evaporating at the same time. Only a few stars every 10,000 years, but has GC specialists examining other resident bulge GCs to see if the behaviour is common. At that velocity is must acquire and lose stars through the LaGrange L1 and L2 points, much like the Jupiter Trojans. If you're into all thus stuff, ask and I can send you the links to the papers.
Ton 2 is also a bulge GC, and relatively nearby HP 1. Visually in my equip't it is the most difficult log I've ever entered as confirmed. Never more than a vague whitish glow with 3 or 4 foreground stars at my 200mm's seeing limit of vm14.5 to 15.3. The test I use is whether nearby NGC 6380 can be seen in the 150mm scope as a cometary glow despite the distraction of a 10.4 mag foreground star. If the 200mm scope can detect hints of granularity in 6380, then the air is good enough to tackle Ton 2. 'Tackle' is a relative word here. There's a whitish quickening at about 2 arcmins dia about 20% of the time. Luckily, the cluster is placed near the vertex of an easily tracked isosceles triangle of 12.75 - 13.25 mag field stars, so keeping the eye directly on it for long periods is easy.
I've devised a last-resort method to confirm objects like this using star counts in four adjacent fields applied to a mathematical formula based on the RMS function used in optical wavefront testing. IYI, The method takes an hour or more of star counting and number crunching, but it is more quantitative than the term 'hesitant glow'. If you are interested in trying the method, look the Wiki article on RMS, and adapt the first long root-square formula. Substitute 'log2.51x, + log2.51y . . . log2.51n’ etc, for the RMS ‘x, y . . . n’ terms. If you calculate the left side of the equation using log2.51 you get a numerically exact solution. I find that to be unsupportable when adjacent field counts number only three or four stars of similar magnitude to the cluster's brightest star. So I do not multiply the left side by the log2.51, which then becomes a probability function. For me that is more reliable.
In the literature, Ton 2 has received about as much attention as it has in enthusiast circles like our own. Next to nil, in other words. Too bad. It's like the long-lost cousin you finally located on Google, wrote, and received a 'deceased' notice in reply.
Cheers and thanks for the data . . .
=Dana in S Africa
Great to hear you have observed them and take heart that I spent a good part
of a year of my life hunting down historical co-ordinate errors such as the one for Ton 2.
Even the NGC was riddled with them.
Thanks for the detailed background on what is happening in the case of HP 1
and the puzzle it provides. By all means, please forward the links.
Great to hear you are bringing statistical techniques to bear as part of visual
observation! That's dedication. We Electrical Engineers love using Root
Mean Square metrics and Argo Navis reports its pointing performance in
terms of Root Mean Square (RMS) and Population Standard Deviation (PSD)
values.
I just had a look on Google maps where the village of Nieu Bethes was in the Karoo
and I can imagine you must have exceptional skies there.
One globular that I haven't seen is UKS 1. I've observed for a few hours one night
with Barbara Wilson in Texas. I know she has seen it in a 36" Dob that I
also got to look through that belongs to Larry Mitchell. I don't believe Australian
friend Andrew Murrell has ever seen it either, but I will ask.
Thanks again for the detailed response and that fascinating background.
Hi Dana & Gary will give them a go tomorrow night, weather permitting.
Will report my findings
I remember observing Ton 2 many years ago with a friend he using a 20"scope me using my 16" and we both confirmed the observations in each others scope,unfortunately I can't find my observation report.
I have never attempted HP1 so it should be an interesting exercise.
Cheers
TON2 - Les Dalrymple presented some observational information in the July 2002 issue of Sky & Telescope (Australia or US I am not sure) " 6' N-WEST OF 4.3 MAG STAR;10 INCH NO HINT RESOLUTION OR CENTRAL CONDENSATION"
It is also listed in the revised Hartungs as object 823.
HP1 - is listed in the revised Hartungs as object 817 - "SMALL FAINT GLOBULAR NO SIGN RESOLUTION;LARGE APERTURE HELPS"
I may have seen TON2 visually with my old Galaxy Optics 14.5inch in the early 2000s from a very dark Leyburn sky but I cant find any notes to be sure.
Hope this helps.
Hi everyone. I've attached some helpful HP 1 finder & observation charts.
HP 1 is difficult in part because its surf brightness is <14.5. The listed magnitude of 11.6 is very misleading as it is spread out over the listed tidal radius of 8.1 arcmin. (Tidal radius is the boundary between the cluster's gravitational well and the Galactic well, in this case the Galactic well is the bulge surrounding HP 1; the Galactic arms and bar have little effect on the cluster compared with the bulge.) For me, a better measure of observability in any globular is the half-light radius, the diameter where half the light is concentrated. In HP 1's case that is 3.1 arcmin. That, too, is misleading due to the remarkably concentrated cluster. HP 1's core radius of 0.03 arcmin (1.18 arcsecs) due to binary clustering in a minute core. The attached images make this clearer.
If you are using a go-to, the coordinates are RA 17 31 05 Dec -29 58 54. I am limited to star-hopping with a laser finder, so find objects by triangulating from the crossing points of 3 imaginary lines from nearby reference stars. I use Michael Vlavsov's Deep Sky Atlas printed on A-3 format paper plus downloaded DSS 20 and 5 arcmin field images that reach to ~mag 16.
Use the attached image 01 DSS 20' field to locate HP 1 in the field. Near the bottom of the image is an arc of six mag 12-13 stars 9 to 10 arcmins S; these show up much better in the eyepiece as a vivid 4-star chain with outliers. Above the cluster is a tent-shaped alignment of six 12-13 mag stars 5 to 7 arcmins N. Very close to the cluster core is a shallow triangle of three 13th mag stars 2 arcmins out. These are the stars to use pinning down the faint core. It is made easier by imagining the three stars as forming a Draco head with the cluster core as the nose. In my scope the core shows as only slightly fainter than the shallow triangle, ~13.5 to 14. The unresolved glow around the core reaches halfway to the triangle, roughly 1.5 arcmin, and is very fleeting. Even when the field is near-zenith about midnight here, it still requires a lot of patience and steady gazing. Once you do glimpse it, it will fade in and out of the seeing variations much more readily.
The rest of the images show the core concentration more accurately and will give you a better idea what to search for. Attached image 02 is 1.7 arcmins square. The 'ears' and 'neck' of the 3-star 'Draco' asterism is out of the field to the N in this image. You can see how tight the core really is. The numbers & letters on this image are from a study of nearby bulge-vs-cluster stars. The small lettered stars are blue horizontal branch stars, the cap letter stars are field red giants, and the numbered stars are cluster red giants. This is an IR image, which makes the red giants seem brighter than they appear in the eyepiece.
Image 03 shows the cluster in a B&W 2MASS field and the reversed field is from a VLT 8-metre IR study.
Glen, I will get back to you with the paper citations and references. You can start with a search for HP 1 on arXiv, IOS, and ADS. You can narrow the search with the date range 1997-2013 and use the names, Bica, Dotter, Minniti, Ortolani, Dotter, Barbuy, Bica, Davidge, Carollo, and Freeman.
I can't help much with spotting UKS1, Gary. For some reason it isn't showing up in my 80mm refractor.
There seems to be no end in sight for the bulge globular list. A couple of years ago yet another tiny smudge comprising, say, 50,000 or so stars, VVV Cl001, was found only 8 arcmin from UKS1 and is thought to be bound with UKS1. If you’re tempted, it is visual band mag 16.5 and surface brightness <m25 and was not detected on the Palomar plates. The paper, with image, is here.
As for HP 1, attached are some more interesting images showing its relevance in the larger Galactic Bulge framework. Image # 7 is really interesting because it shows what happens to a globular plowing through the bulge density medium, gaining stars in front and losing them behind, at the stately pace of 64 kms/sec. The Bica 1997 paper states that it may gain and lose between 7000 and 9000 stars per billion years. There's a cosmic metaphor for something in all this, but I can't think of it right now.
And some papers:
Ortolani 2011 (source of image 03 in my last post). Also Ortolani's 1997 paper, which shows just how far we've come when telescopes jump from 3 meters dia to 8 meters.
More broadly on recent developments in understanding globulars come from your own Ozzies Sarah Martell (especially papers 3, 5, 9 & 10 on the list); Daniela Carollo; Tim Beers, and Kenneth Freeman, whose resume (303 papers!) reads like an heir-apparent to Sidney van den Bergh.
PS, Gary. We astro nerds refer to PDS as Gaussian functions. They have curves much like PDS. Sorta like blondes and brunettes for the differential-equation set.
i had a look last night to see if they were visable with my 16"lightbridge..
the moon was up still and a little bright spending time on both with setting circles very confident i was in the right area but not visable to the eye....
the night before i was in dome with my 14" sct and using video astronomy and a fov of around 12 arc mins was able to see both very easily...
I've been itching for some good transparency to chase these down and managed to get HP 1 in my sights last Friday night. I was in the right spot for Ton 2 but couldn't be confident that I saw it.
Here are my notes for HP 1
Haute Provence 1 (HP1) GC in Ophiuchus
175x Very faint circular glow just visible, perhaps 1.5-2’ dia, but hard to pick the edges
You 'Globular fanatics' are an impressive and erudite bunch!
( I am always very impressed by knowledgable 'astro dudes'.)
It is possible to find a mega summary of the current state of Star Cluster research in IAU Symposium 266, "Star Clusters : Basic Galactic building blocks throughout time and space".
I know that Dana loves to really get deep into the intricate details of this sort of stuff!
It is not necessary to pay a King's Ransom for the paper version of this symposium write-up. The papers can be freely accessed at: http://journals.cambridge.org/IAU
The proceedings of IAU meetings are one of the best ways to find out the latest information about most every aspect of scientific astronomy, and their access policy for online papers is remarkably liberal.
Robert is right about free access to some of the IAU proceedings. Not all are free downloads, though, and some are truncated data. IAU is playing it nice, while some other publishers are a bit less forthcoming. Luckily, we can access almost all the pricey professional papers by copying down the lead (or other) author names and the key words of the article title, then searching them as key words on arXiv.org, IOP, ADS (Astronomical Data Service), or the yandex.com search engine. There are scads of other resources, but the above four seem to come up with the best & the most.
If you are interested in the original historical papers which are the founding documents of astronomy as we know it, a search on the UK Google Scholar or USA equivalent Google Scholar comes up with papers by the likes of Edwin Hubble, Fritz Zwicky, Harlow Shapley, the Burbidge-Fowler-Hoyle collaboration, etc. You'll also find how windy and proceduralized papers have become since the flood of aspiring Ph.Ds came onto the market looking for jobs starting in the early 2000s. There are now roughly 20,000 professional astronomers (i.e., getting paid) in the world. A r-e-a-l-l-y big plus-mark for this profession is that nearly half of all the professionals are women, and a perusal of author names on the papers shows just how many of them can write as well as they can crunch data.
. You'll also find how windy and proceduralized papers have become since the flood of aspiring Ph.Ds came onto the market looking for jobs starting in the early 2000s. There are now roughly 20,000 professional astronomers (i.e., getting paid) in the world. A
In my opinion, the average PhD thesis in astronomy is not very impressive. After all, what is the point of adding 0.00001 percent to the existing knowledge of an astronomical subject?
I have read a lot of PhD theses in extragalactic astronomy, and I think that you or I could have just about written some of them ourselves, despite our more 'humble' status of doing astronomy just for fun and enjoyment.
Added in edit:
I note that Carollo got her PhD in 2011 at ANU, but she has published rather a lot of papers since 2002
This sounds like a person who already proved that they could do research, even had they not submitted to the ordeal of doing a PhD.
Just getting a PhD does not prove that a person can do research; indeed there were plenty of astronomy PhDs who were unable to go on and do the work of a researcher.
However, I am sure that Carollo would be employable even without her PhD, as she is obviously able to do the work.
As you remarked, there seem to be an awful lot of Australian PhD theses coming off the production line. Another institution which is producing them is Swinburne University.
Last edited by madbadgalaxyman; 12-07-2013 at 10:07 PM.
Daniela Carollo is one of my favorite authors, very clear and readable. I also like her colleague Sarah Martell, who is aces on clusters and stellar populations. Add Ken Freeman and you folks have a lot of good researchers who also know how to combine writing well with solid analysis. They don't strump up the technical terms to cover up unclear thinking. I learn a lot from these three.
