PAL10

Palomar 10 is Sagitta's "other" globular cluster. It is about 19,000 light-years distant and about 21,000 light-years from the center of our galaxy. To see it, you have to look through some of the heavy dust in our galaxy. To come through as strong as it does (magnitude 13.2) it must be a much grander object than what little gets through to us. Because of all the dust, it is severely reddened. It was discovered by A. G. Wells in 1955 making it one of the earlier Palomar globulars found. It is one those with a 12" scope or larger should have little trouble finding though even in large Dobs of 30 inches only 3 to 5 stars are seen in it.

There is little on this globular. It is surprisingly metal-rich. The only paper on it I found is at:
http://adsabs.harvard.edu/full/1997PASP..109..920K The paper covers a similarly obscured but brighter globular NGC 6749 as well as Pal 10. I've added that one to my ever growing to-do list. That has since been imaged and is or will soon be added to the NGC section of my webpage.

NED lists not one galaxy in my field. Not surprising as this is one of the most heavily obscured areas of the sky.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for PAL10

PAL11

Palomar 11 (Pal 11) is located in Aquila about 47,000 light-years from us and 27,000 light-years from the center of the galaxy. It was discovered by George Abell in 1955 on the Palomar Observatory Sky Survey plates. It is rather bright with a magnitude of 9.8. Reports show it being seen in an 80mm refractor though another note says it was seen with direct vision only occasionally in a 6" scope. One paper puts its age at 10.4 +/-0.5 billion years.

I suspect some of the more colorful stars across the globular are really foreground stars and not cluster members as the starfield is quite rich being in the edge of the Milky Way. Does make it look a bit more like a dense open cluster than a globular cluster.

There are a few galaxies in the image. Only one has redshift data. It is 2MFGC 15113 at 590 million light-years. It is on the left edge near the bottom. 2MFGC means it is in the 2 Micron Flat Galaxy Catalog so look for an edge on needle galaxy half off the image though the core is just on the edge. For some reason, I thought the flat galaxy was to the north so moved the globular down to catch it. Not sure how I managed to get my directions so messed up.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for PAL11

PAL13

Palomar 13, found in Pegasus, is located about 85 thousand light-years away and about 88 million light-years from the center of the galaxy. While SIMBAD and a note at NED says it is an intergalactic cluster this is likely incorrect. SEDS has this to say about it: "Palomar 13 was discovered by A.G. Wilson (1955) and named by him the Pegasus Globular Cluster, together with globular clusters Palomar 3, Palomar 4 and Palomar 5, and two new Local Group galaxies. That naming was certainly not essentially a happy choice, as Pegasus also contains the prominent globular M15. G.O. Abell (1955) cataloged them with their Palomar numbers."

Note that it has an unusual number of very blue stars. These are likely high mass stars that are the result of the union of smaller, dying red stars. The merger has given them twice the mass causing them to turn into hot blue stars -- for a short time at least. It's orbit about our galaxy, according to the paper below, shows it dives in rather close to the galaxy's core then out into the halo again where we see it is today. This will tend to strip it of its less massive stars leaving mostly the more massive stars, many of which are blue stragglers. Their calculations indicate that it is now so depleted of stars and thus its next nose dive into the core will be its last as there's not enough left to resist the tidal forces of our galaxy's core.
http://xxx.lanl.gov/pdf/astro-ph/0011220v1.pdf

An image of it taken at the Las Campanas Observatory in the Atacama Desert of Chile is at APOD. http://apod.nasa.gov/apod/ap001130.html They don't say which scope took it. It is rotated so west as at the top rather than north in my image. It appears to be a somewhat false-color image.

Interestingly, three of the 4 entries in NED call it a galaxy. I assume they saw it as a nearby dwarf galaxy. Apparently, if you look for galaxies you find them even when they are something else.

There are a couple of asteroids in my image. (287071) 2002 RZ28 at an estimated magnitude of 19.3 is east of Pal 13 while (170485) 2003 UC277 at an estimated magnitude of 18.4 is toward the upper right corner.

For reasons now lost to my memory and not in my notes, I went back the next night and retook my normal 2 frames in each color. While the first night wasn't quite as transparent of a night as the second I did use all four of each in composing the image.

I've not prepared an annotated image. Most of my data for such images come from the Sloan database at NED. That starts at 13 degrees which is the very top of my image so except for the top minute of arc, the image is out of their data at NED.

14" LX200R @ f/10, LRGB=4x10', STL-11000XM, Paramount ME

Related Designations for PAL13

PAL14

Palomar 14 (Pal 14) is probably the least well known globular cluster in Hercules. It is just over the border from Serpens Caput, in fact, the right 40% of the image is in Serpens Caput. The cluster is one of the most distant known in our galaxy being some 250,000 light-years away from us and 230 thousand light-years from the galaxy's center (I found other estimates that were slightly different). It was discovered by Sidney van den Bergh while searching the Palomar survey plates and confirmed by Halton Arp with the 200" scope. This is why it is also known as AvdB.
http://adsabs.harvard.edu/abs/1960PASP...72...48A

The cluster may have two one degree long tidal tails. At least this is what one paper claims. This leads to the possibility it might have belonged to a small galaxy the Milky Way digested many billions of years ago. The cluster is considered to be about 3 billion years younger than most in our galaxy. The two may be related.
http://arxiv.org/abs/1010.6303

There are reports of it being seen in a 20" dob as a soft round glow at magnitude 14.7 which seems rather bright to me. It certainly isn't much to look at in my image. It is very sparse containing a mass of only about 6000 solar masses. More the size of a rich open cluster than globular. The estimates are likely low as it is hard to determine at its vast distance. Consider these a lower limit.

It is also known as Arp 1. In fact, if you use SIMBAD and enter Arp 1 you will get this globular rather than the galaxy Arp 1. Enter Arp 01 and you get the galaxy. This has confused more than one amateur trying to hunt down the galaxy or globular. NED, on the other hand, returns the galaxy and doesn't even know the globular exists. Not surprising as it is mostly an extragalactic database.

A few galaxies and galaxy clusters that are in my field have redshift data so I did prepare a rather sparse annotated image.

14" LX200R @ f/10, L=4x10 RGB=2x10, STL-11000XM, Paramount ME

Related Designations for PAL14

PAL15

Palomar 15 was cataloged by many as a galaxy. The Karachentseva Isolated Galaxy Catalogue says of it; "Resolved dwarf system. ...bright nucleus and diffuse halo." It is also listed by the UGC, PGC, MCG and CGCG catalogs as a galaxy. UGC also calls it a dwarf system. But it is a globular cluster in Ophiuchus where many of our galaxy's globular clusters reside. It is about 145,000 light-years distant on the far side of our galaxy, 125,000 light-years from the center. So it suffers quite a bit of extinction making it even dimmer than it already is. While listed at 14.2 magnitude it is extremely difficult in an 18" scope and hardly better in larger ones. Sources vary as to the discoverer. It was discovered in 1959. Some sources credit George Abell, others Fred Zwicky. It has the largest diameter core of any known globular but is of such low density it obviously has never been near the galaxy's core or it would have been completely ripped apart in one pass. You can read more about it at: http://articles.adsabs.harvard.edu/full/1990AJ.....99..229S

Only a handful of the galaxies in the image are listed at NED and none with redshift data so I've not prepared an annotated image. There's an asteroid in the image, Renaldowebb, near the west edge (right). It is at an estimated 18.3 magnitude. The naming citation reads: "(21674) Renaldowebb = 1999 RG18 Renaldo Michael Webb (b. 1988) was awarded second place in the 2006 Intel International Science and Engineering Fair for his physics project. He attends the Louisiana School for Mathematics, Science, and the Arts, Natchitoches, Louisiana, U.S.A."

14" LX200R@ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for PAL15

PAL2

The 15 Palomar globular clusters were found by scrounging the POSS 1 plates back in the 1950's. This was done by astronomers looking for other objects so many contributed to the list. Since no one name could be put on the list it was named for the observatory. Those finding one or more include Harlton Arp while looking for his famous peculiar galaxies and George Abell looking for planetaries and galaxy clusters. Other contributors you might have heard of are Edwin Hubble, Walter Baade and Fritz Zwicky.

The Palomar globular list is small so I decided to add it to my project list. Pal 1 is too far north in my Polaris trees (since cut down due to rot) forcing me to start the project with Pal 2 in Auriga which was discovered by A. G. Wilson in 1955. It is thought to be about 90,000 light-years from us and 115,000 light-years from the galaxy's center so this one is far out in the outskirts of the galactic halo. It's brightest stars are about magnitude 18.8 and are surprisingly red. In fact, the entire cluster is very red. This is because it is heavily obscured. The dust gives it a rather odd color somewhat orange instead of golden that you'd expect.

I found this in the abstract of a 1998 paper by W.E. Harris et al of McMaster University. "Palomar 2 is a distant and heavily obscured globular cluster which, unlike the vast majority of such clusters, is located near the galactic anticentre direction. Though it is possibly one of the rare outer-halo clusters that are important tracers of the mass distribution and formation history of the halo, virtually nothing has been known about till now." It continues: "It's integrated luminosity Mvt~=7.9 makes it brighter and more massive than all but one or two other clusters in the outer halo. Very rough arguments based on its half-mass radius and radial velocity suggest that Palomar 2 is now moving in toward perigalacticon on a highly elliptical orbit (e>= 0.7)." Perigalacticon is a fancy word for its closest approach to the galactic center.

Due to the obscuring cloud, external galaxies are mostly missing from this image. NED lists about a dozen in my field. Only their cores survive the obscuring cloud so they look just like very faint stars. No distance data is available for them. All are from the 2MASS IR survey. I didn't try to annotate them.

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM Paramount ME

Related Designations for PAL2

PAL3

About 6 days ago I posted my image of Palomar 4, the most distant Palomar globular and second most distant one known. Palomar 3 is the third most distant globular known. It is about 302,000 light years from earth and 313,000 light years from the center of our galaxy. It is located in the constellation of Sextans. I won't be imaging the most distant known as it is always below my horizon.

Palomar 3 was discovered by A.G. Wilson in 1955, he called it the Sextans Globular Cluster. George Abell then cataloged it as Palomar 3 along with Palomar 4, 5 and 13 the same year. But others, unaware of its true nature thought it a nearby dwarf elliptical or spherical galaxy probably in the local group. That resulted in it being named Sextans C (Sextans A and B are real dwarf galaxies still on my to-do list). It doesn't help that it is only 4 degrees from the Sextans Dwarf Spheroidal which is a satellite of our galaxy discovered long before in 1900 even though it is so faint I can't see it on the Palomar plates so haven't tried imaging it. The two are only about 30,000 light-years apart. The Sextans Dwarf Spheroidal is so close it covers more than my field of view. While close to each other they have very different radial velocities indicating they are not related. According to NED Palomar 3 is still listed as a galaxy in the CGCG, MGC, UZC and a couple other catalogs. The UGC lists it as a galaxy, UGC 5439, and as a globular, UGC 5439 ID according to NED.

The annotated image contains quite a few very faint and distant galaxies. There are several galaxy clusters shown in NED but only the anchoring big cluster galaxy of each is seen in my image in most cases. I've indicated the galaxy count as shown by NED even though most don't seem to show in my image. If the distance to the cluster and related galaxy are different the cluster's distance is shown first. As usual, all distances are in billions of light years which results in a lot of zeros for nearby Palomar 3. A "p" after the distance indicates it is a photometric determination of distance. Labels for Galaxies, Quasars, Galaxy Clusters and Ultraviolet Excess Sources are placed just to the right of the object when possible. Otherwise, a line will point from the label to the object. Nearby galaxies are listed by catalog name, those cataloged only by location are simply labeled as to the type of object. A question mark labels one galaxy I happened to notice that wasn't in NED at all. They miss some, usually blue ones though not in this case. Some distant galaxies are so faint you may need to enlarge the image several times to even see them. All that NED had redshift data for are listed using NED's 5 year WMAP light travel time distance calculator.

Light travel time distance is the distance the light traveled to reach us. The object was closer when the light was emitted but during the billions of years it took to get here the universe's expansion forced the light to travel a greater distance. "Now" the object is even further away. In cases of those objects over about 9 or 10 billion light-years distant by light travel time they are likely so distant they are moving away "now" faster than the speed of light so light they emit today will never reach us. Though since they are quasars they are likely dormant by now so no longer visible in any case.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for PAL3

PAL4

Palomar 4 is the most distant of the Palomar globulars. It is located in Ursa Major some 356,000 light-years from earth. It was originally discovered by Edwin Hubble in 1949 but before that was published A.G. Wilson also found it in 1950. Wilson named it the Ursa Major Globular Cluster and published it along with Palomar 3, 5 and 13 as well as two galaxies. Wilson's classification as a globular was considered unsure and it was cataloged in the UGCA Catalog as a dwarf galaxy in our local group. The UGCA is an appendix of 400 galaxies added to the UGC catalog limited to late-type spirals, irregulars and dwarf systems -- and an occasional globular cluster it would seem. It was even given the common name "The Ursa Major Dwarf."

I could find only one globular that is more distant than Palomar 4. That is AM 1 but at declination -49.6 degrees it is always below my horizon. Its distance is listed as just under 400 thousand light-years. It is also the most distant from the core of our galaxy at just over 400 thousand light-years. Palomar 4 is the second most distant both from the sun (354,400 light-years) and from the galaxy's center (362,500 light-years). I'm a bit confused about the orange stars seen against the cluster. Most sources say the brightest star in the cluster is 18th magnitude but 7 brightest orange stars are 16th to 17th magnitude by my measurement. Some or all may not be cluster members. I just don't know.

While I was able to resolve quite a few stars in the globular seeing was quite poor running about 3.7" FWHM. Under better seeing, I'd likely pull in a lot more stars in the cluster. It's on the reshoot list but it is in a part of the sky with several hundred objects I've never imaged. I might get to it if I live to be 100 so don't hold your breath.

Normally globulars are seen looking toward the core of our galaxy but this one is almost opposite the galaxy's core which means it is in a very unobscured part of the sky. For a change, there are a lot of galaxies in this globular image. They seem more common than foreground stars. While NED lists a couple thousand galaxies in the field only a few have redshift data. I annotated all of those. Nearly all have catalog names that are just their position in the sky. I list those only by type of object all of which are galaxies in this image. There was one galaxy, a flat galaxy from the 2MASS survey, that is listed by name and one galaxy group. It consists of 4 members, all of which are easily seen in my image A line points to the center of the group as defined by NED. Distances are noted in billions of light-years which makes for a lot of leading zeros in the case of Palomar 4!

14" LX200R @ f/10, L=10x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for PAL4

PAL5

Palomar 5 is located about 61,000 light-years from earth and 75,000 light-years from the center of our galaxy. We see it in the constellation of Serpens Caput. Palomar 5 was discovered twice. First in 1950 by Walter Baade then in 1955 by A.G. Wilson. Wilson gave it the rather useless name of the Serpens Globular Cluster as if it was the only such cluster in the constellation, the others are all larger, brighter and with more stars including M5 only 2 degrees to the north. Maybe Serpens Least Globular Cluster would be a better name. Still, it was named Serpens Dwarf by some who thought it a dwarf galaxy rather than a globular cluster. The UGC says "Resolved dwarf -- Very uncertain diameter values". The CGCG and MCG also list it as a galaxy.

It has been discovered that our galaxy is shredding the globular creating a long tidal stream on either side of the cluster that contains far more stars than are left in the cluster. This explains its weak structure. You can read about this at: https://arxiv.org/pdf/astro-ph/0209555v1.pdf

Color data is a bit weak as I was only able to get one round before clouds moved in. Located on the celestial equator I needed a better than average night to get more which never happened then I forgot about it until I processed the image.

Thanks to the excellent seeing (for my location) this night I was able to go rather deep even under the somewhat hazy conditions. The annotated image shows some really faint on odd objects. One, on the east side of Palomar 5 has two listings in NED. One as a quasar and another as AbLS which stands for Absorption Line System. The Red Shift of the quasar is z=3.749290 while the AbLS has a z of 3.030000 putting it some 480 million light-years closer. My interpretation of this is that there is an object, dust and gas cloud for instance) that lies between us and the quasar adding its absorption lines to the spectrum of the quasar. The combined light is green in the Sloan survey image due to it mapping blue to green and Uv -- likely lost to the dust cloud -- mapped to blue but with none, the object turned green in the SDSS pseudo color image.

One quasar at 7.91 billion light-years had its redshift determined from a single spectral line. This only works if you are absolutely certain what that one line is.

There are quite a few galaxies in the upper part of the image a bit left of center at about 1.5 billion light-years. They are likely member of Abell 2050, a galaxy cluster about 18 minutes across (nearly the height of my image) centered a couple minutes of arc above my image and a bit left of center.

I found 20 quasars or likely quasars (UvES) in this small field. The most of any field I have imaged as best I can recall. A dozen more are just beyond the borders of the image. Arp made a big deal about quasars being ejected from nearby galaxies but none of his examples had more than a half dozen quasars in a similar area. Apparently nearly washed up globulars eject far more or else his theory is seriously flawed. I vote for the latter. One of those quasars lies at a measured z value of over 3 though NED notes this is uncertain. How uncertain they don't say.

14" LX200R @ f/10, L=4x10' RGB=1x10', STL-11000XM, Paramount ME

Related Designations for PAL5

PAL7

PAL7/IC 1276 is a type XII globular cluster in Serpens Cauda. It's about 17,600 light-years from us and about 12,100 light years from the center of the galaxy. That makes it one of the closest Palomar globulars and one of the brightest. It is the only one with an IC number though Pal 9 has an NGC number. Unfortunately at -22 degrees Pal 9 is to low for me unless the night is exceptional which hasn't happened as yet. While listed as an IC object Pal 7 was first discovered as a globular by Lewis Swift on April 19, 1889 but is considered to be "discovered" as a Palomar globular by George Abell in 1955 after study of the Palomar Observatory Sky Survey plates. It's hard to tell what the original IC catalog thought it was. The description doesn't include that information. It reads eeF, vL, v diffic, D* close p. Translation "Most Extremely faint, very large, very difficult, a double star close to the west." I assume the double star referred to is the pair of bright stars on the right side of the cluster in my image. I see nothing else. Since most open clusters and globulars are far larger than this and it was considered large it appears they saw no stars in it at the time so didn't consider it to be a star cluster of any type. Back then there were just star clusters and starless nebulae. While some of its brightest stars are at magnitude 15 apparently they weren't resolved against the glow of the cluster itself.

Seeing wasn't all that good for this one.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for PAL7