Celestial Atlas
GCL 100 - 125 ←Non-GCL Milky Way Globular Clusters→ GCL 1 - 49
Click here for Introductory Material
Page last updated Aug 29, 2022
Moved entry for HP1 to GCL 67
Editing but essentially done with Terzan 2

QuickLinks:
2MASS, Arp-Madore (AM), BH, Djorg, Eridanus, ESO, FSR, IC,
Laevens, Liller, Lynga, Mercer, Palomar, Pyxis, Ruprecht, Terzan, UKS, VVV, Whiting

2MASS GC01
(= Hurt 1)

A magnitude 27.7 globular cluster (type ?) in
(RA 18 08 21.8, Dec -19 49 47)
Discovery: This cluster and 2MASS GC02 were accidentally found by Hurt et al while looking at 2MASS infrared images of the region.
Physical Information: 2MASS GC01 is completely invisible in visible light, due to roughly 21 magnitudes of extinction by dust lying between us and the cluster, which lies nearly in the plane of our galaxy. It and its "companion" (in terms of their discovery) undoubtedly formed billions of years ago, but (per Ivanov et al) are thought to have a relatively high "metal" content (that is, a small percentage of atoms other than hydrogen and helium) in comparison with other globulars. The cluster has a low-eccentricity orbit near the outer part of the galactic bulge, ranging from about 11 to 16 thousand light-years from the center of the galaxy, but its more or less constant gravitational interaction with the bulge causes its orbit to rotate about a third of the way around the center of the galaxy each time it goes around the center.
 Based on an estimated distance from the Sun of about 10 thousand light-years and an apparent size of about 3.3 arcmin, the cluster is about 10 light-years in diameter.
PanSTARRS image of region near globular cluster 2MASS GC01
Above, a 12 arcmin wide PanSTARRS image centered on 2MASS GC01 shows no sign of the cluster
Below, a 6.75 arcmin wide PanSTARRS image of the area shown in the box above
PanSTARRS image of region near globular cluster 2MASS GC01
Below, a 6.75 arcmin wide infrared image of the same region (Image Credit IPAC, 2MASS)
2MASS infrared mosaic of globular cluster 2MASS GC01

2MASS GC02
(= Hurt 2)

A magnitude 24.6 globular cluster (type ?) in
(RA 18 09 36.5, Dec -20 46 44)
Discovery: This cluster and 2MASS GC01 were accidentally found by Hurt et al while looking at 2MASS infrared images of the region.
Physical Information: 2MASS GC02 is not detectable in visible light, due to roughly 15 magnitudes of extinction by dust lying between us and the cluster, which lies nearly in the plane of our galaxy. It and its "companion" (in terms of their discovery) undoubtedly formed billions of years ago, but (per Ivanov et al) are thought to have a relatively high "metal" content (that is, a small percentage of atoms other than hydrogen and helium) in comparison with other globulars.
 Based on an estimated distance of about 14 thousand light-years and an apparent size of about 1.9 arcmin, the cluster is about 8 light-years in diameter. It has an eccentric orbit which keeps it in or near the nucleus of our galaxy, with distances ranging from as little as 12 to 13 hundred light-years from the nucleus to as much as 8500 hundred light-years. Because of its constant interaction with stars in the nucleus its orbit changes after each passage, and it has undoubtedly lost most of its mass and members over the aeons.
DSS image of region near globular cluster 2MASS GC02 shows dense absorption clouds that completely block its visible light
Above, an 18 arcmin wide DSS image centered on 2MASS GC02 shows dense absorption features
Below, a 6.5 arcmin wide DSS image of the region in the box above shows no sign of the cluster
DSS image of region near globular cluster 2MASS GC02
Below, a 6.5 arcmin wide infrared image centered on 2MASS GC02 (Image Credit 2MASS, S. Van Dyk (IPAC))
2MASS infrared image of region near globular cluster 2MASS GC02

2MASS GC03
(= FSR 1735)

A magnitude 14.0 globular cluster (type ?) in Ara (RA 16 52 10.6, Dec -47 03 29)
Discovery: Discovered by Froebrich, Scholz and Raftery (whence "FSR") using the 2MASS infrared telescope.
Physical Information: Like the other "2MASS" globular clusters. GC03 is virtually undetectable in visible light. though in this case the obscuration by dust is only about 4 1/2 magnitudes, so depending on the processing of DSS images it can appear that there is a faint glow (or not) at the cluster's location. The cluster has an eccentric orbit which carries it inward to just over 3000 light-years from the center of the galaxy, then out to more than 15 thousand light-years distance in each passage around the galaxy. Its interaction with stars within the central part of our galaxy causes the orbit to change its orientation at every passage, and has undoubtedly cost it most of its stars and mass during the hundred or two times that it has passed through the central part of the galaxy. The cluster's age is unknown, but it has a relatively high abundance of atoms other than hydrogen and helium, containing 10 to 15% as many such atoms per million as the Sun, whereas the oldest globulars have only a percent or so of the Solar abundance of such atoms. It is therefore thought to be on the "young" side for a globular cluster (though that can mean 10 or 11 billion years, and it is certainly much older than the Sun and most of its neighbors). The cluster is currently about 30 thousand light-years from the Sun. Given that and its apparent size of about 1 arcmin (hard to determine since it barely stands out from the "field"), it is about 8 to 10 light-years in diameter.
DSS image of region near globular cluster FSR 1735, also known as 2MASS GC03
Above, a 12 arcmin wide DSS image centered on the location of FSR 1735 (barely visible as a faint glow)
Below, the central 4.75 arcmin of the image above still shows only a hint of "something" at its center
DSS image of globular cluster FSR 1735, also known as 2MASS GC03
Below, a 4.75 arcmin wide infrared image of the cluster (Image Credit ESO, Henri Boffin (ESO))
ESO infrared image of globular cluster FSR 1735, also known as 2MASS GC03

Arp-Madore (AM) 1
(= E 1)


AM 4


BH 176

BH 261


Djorg 1

Djorg 2
(= ESO 456-038)



Eridanus


ESO 037-001
(= E 3)


ESO 280-006

ESO 452-011


FSR 1716

FSR 1758


IC 1257


Laevens 1
(= Crater Cluster)


Laevens 3

Laevens 5
(= Sgr 2)



Liller 1
(= PGC 4662809)

Discovered (1977) by William Liller
A magnitude 15.7 globular cluster in
Scorpius (RA 17 33 24.5, Dec -33 23 20)
Observational Note: Liller 1 lies behind so much interstellar dust that it is completely invisible at "visual" wavelengths, as seen in the first (DSS) image below. Only infrared images can reveal the cluster itself, although the foreground stars (which are shown as bluish in the HST image and white in the NOAO image) can be seen in the visible-light DSS image, because they are much closer to us and do not lie behind the dust that obscures the globular cluster.
Physical Information: Liller 1 lies in the galactic bulge, only about 2500 light-years from the center of our galaxy, and about 26 to 30 thousand light-years from the Sun. It is one of the most massive globular clusters in the galaxy, with an estimated mass of about 2.3 million Solar masses, and since most globular cluster stars are less massive than the Sun, undoubtedly contains more than 3 million stars. Usually all those stars would be 12 to 13 billion years old, but studies of the cluster indicate that it has two significant populations of stars with ages of 12 and 1-2 billion light-years, so it has either had far more "recent" star formation than other globulars, or has merged with much younger clusters. Like most globular clusters the average "metal" content (that is, anything other than hydrogen and helium) is less than that of the Sun, but at about half the Solar percentage of heavier atoms, it has far more "metal" atoms than most globular clusters, presumably as a result of its younger stellar content.
 The apparent size of such a cluster is difficult to determine, since it just sort of fades into the surrounding field, but based on the infrared images below it is at least an arcmin across, and given its estimated distance, that corresponds to about 8 light-years, which is about the same as its "half-mass" diameter, so its outermost stars probably fill a region 15 to 20 light-years in diameter.
DSS image of region near globular cluster Liller 1 shows no hint of its existence
Above, a 12 arcmin wide DSS image centered on Liller 1 (invisible because of dust in the plane of the Milky Way)
The rectangle shows the approximate field of view of the HST image)
Below, a 3.75 arcmin wide infrared image of the cluster (Image Credit DECaM Plane Survey / NOAO, Holger Baumbardt site; otherwise defunct)
NOAO image of region near globular cluster Liller 1
Below, a 1.38 by 2.0 arcmin wide composite of visible light (for the foreground stars) and infrared radiation (for the cluster)
(Image Credit ESA/Hubble & NASA, F. Ferraro)
Composite of visible and infrared HST image of globular cluster Liller 1

Lynga 7


Mercer 03

Mercer 05


Palomar 01

Palomar 02
HST image

Palomar 03

Palomar 11


Pyxis


Ruprecht 106
(= PGC 4662799 = C 1235-509)

Discovered (1961) by Jaroslav Ruprecht
A magnitude 11.0 globular cluster in
Centaurus (RA 12 38 40.2, Dec -51 09 01)
Physical Information: Ruprecht 106 is about 65 to 70 thousand light-years away. Given that and its apparent size of about 5 to 5.5 arcmin (from various references), it is about 100 light-years in diameter, but about half of its mass is in a region only about 35 to 40 light-years across (and less than a tenth of its volume). It has a very low mass (estimates range from about 35 to 70 thousand Solar masses), and is the only globular cluster known to consist only of very old (about 11.5 billion years), metal-poor stars (that is, containing almost nothing but hydrogen and helium). All other globular clusters have at least two "populations": A metal-poor population as old as the cluster, and a second generation of stars created a billion or so years later from metal-rich gases expelled by supernovae as the more massive stars in the first generation ended their lives. It is thought that it may have originally had such a low mass that there wasn't enough gas released by first-generation stars to enable newer stars to be formed, but there is no way to know how much mass it has lost over the aeons. It is considered a halo cluster necause it can be as much as 100 thousand lighy-years from the center of our galaxy, but it dips to within 6 or 7 thousand light-years of the center every half billion years or so, which means that it could have lost some of its outer stars about 25 times since it was formed.
DSS image of region near globular cluster Ruprecht 106
Below, a 12 arcmin wide DSS image centered on Ruprecht 106
Below, a 6 arcmin wide DSS image of the cluster
(The cluster is the numerous faint stars; all the bright ones are foreground stars)
DSS image of globular cluster Ruprecht 106
Below, a 3.25 arcmin wide image of the cluster (Image Credit ESA/Hubble & NASA, A. Dotter)HST image of globular cluster Ruprecht 106

Terzan 1 (= HP 2)


Terzan 2
(= HP 3 = PGC4662806 = ESO 454-SC029 = "GCL 64.1")

Discovered (1960's) by Agop Terzan
A magnitude 13.5(?) globular cluster (type ?) in
Scorpius (RA 17 27 33.1, Dec -30 48 08)
Physical Information: Terzan 2 is a fairly small globular cluster located within the central bulge of our galaxy. Its orbital motion is moderately eccentric and more or less confined to the central plane of the galaxy, and so small that it only takes about 9 million years to complete an orbit (which means that it has passed within 500 light-years of the center of the galaxy more than 1500 times since it was formed, at least 10 billion years ago). Its orbit gradually rotates around the galaxy, and although not specifically mentioned in any reference that I've seen, it is probably inside and rotating with the galaxy's central bar. Its mass is estimated at about 140 thousand Solar masses, but given its mass to light ratio, the majority of its stars must be considerably less massive than the Sun, so it probably contains at least 300 thousand individual or binary stars. X-ray "flashes" have been observed, which must result from some kind of stellar interaction, most likely involving some binary system or systems. It is currently about 20 to 25 thousand light-years from the Sun, and about 2200 to 2600 light-years from the center of the galaxy, near its apogalaxion (the furthest point from the center of the galaxy) but heading inward, and in 4 or 5 million years will be, as stated above, less than 500 light-years from the center of the galaxy, at its perigalaxion. Its apparent size is a little less an 0.6 arcmin (per Corwin and Baumgardt), which corresponds to a diameter of about 40 to 45 light-years.
DSS image of region near globular cluster Terzan 2
Above, a 12 arcmin wide DSS image centered on Terzan 2
Below, a PanSTARRS image of the same region has numerous missing areas but shows far more detail
PanSTARRS image of region near globular cluster Terzan 2
Below, a 3 arcmin wide image centered on the cluster (Image Credit DECaM Plane Survey / NOAO)
NOAO image of region near globular cluster Terzan 2
Below, a 2.4 arcmin wide image centered on the cluster (Image Credit ESA/Hubble & NASA, R. Cohen)
HST image of region near globular cluster Terzan 2
Below, a 1.0 arcmin wide image of the cluster (Image Credit as above)
HST image of of globular cluster Terzan 2

Terzan 3


Terzan 4
(= HP 4)



Terzan 5
(= Terzan 11)

Discovered (1968) by Agop Terzan


Terzan 6
(= HP 5)

Discovered (1968?) by Agop Terzan


Terzan 7
Discovered (1968) by Agop Terzan


Terzan 8


Terzan 9
(= PGC 4662817 = ESO 521-SC011 = "GCL 80.1")

Discovered (1960's) by Agop Terzan
A magnitude 13.5(?) globular cluster (type ?) in
Sagittarius (RA 18 01 38.8, Dec -26 50 23)
Physical Information: Terzan 9 is a roughly 11 billion year old globular cluster located within the central bulge of our galaxy. Orbital calculations suggest that it orbits the center of the galaxy about once every 30 or so million years, with a strongly elliptical orbit that co-rotates with the Milky Way's bar, and therefore very nearly in the central plane of the galaxy. Its closest approach to the center is usually between 1300 to 2100 light-years, and its furthest distance from the center lies between 7200 and 8500 light-years. At the moment it appears to be about 8000 light-years out, and headed inwards; but its actual distance could be anywhere between 7 and 9 thousand light-years from the center. Its distance from us is equally uncertain (and is the main reason for the uncertainty in its position relative to the galactic center), but is thought to be between 17500 and 20000 light-years. The cluster's mass is thought to be about 120 thousand times that of the Sun, but its stars are mostly considerably cooler and fainter than the Sun, so it probably has more than 200 thousand members, despite having passed through the central region of our galaxy at least 40 times since its formation. Estimates of the apparent size of the cluster range from about 2 to 3 arcmin, which corresponds to a physical size of about 10 to 15 light-years. Like many globulars, Terzan 9 contains stars with a very low "metal" content (that is, hardly anything other than hydrogen and helium), indicating that almost all of its stars were formed too early in the history of our galaxy to have formed from metal-rich gases expelled by the death of the most massive members of the cluster.
Note About Images: As can be seen in the PanSTARRS image, most of the region to the right of and below Terzan 9 looks darker and contains fewer stars than the region to the left and above. That is because there are dense clouds of interstellar dust blocking our view, or at least considerably reducing the amount of visible light that can reach us. The HST image only shows the cluster as well as it does because it combines visible light images with false-color infrared images that are not as badly affected by the dust.
 The original HST image, once aligned North-South, is a diamond-shaped region roughly 3 arcmin across (use the URL in the Image Credits to see it). I have cropped it to 2.25 arcmin so that the central region can be more easily compared with the PanSTARRS image, which shows the same pattern of brighter stars, albeit considerably reddened and with far less detail.
PanSTARRS image of region near globular cluster Terzan 9
Above, a 12 arcmin wide PanSTARRS image centered on Terzan 9 (interstellar dust dims and reddens it)
Below, a 2.25 arcmin wide image of Terzan 9 (Image Credit ESA/Hubble & NASA, R. Cohen)
HST image of globular cluster Terzan 9
Below, a 1.0 arcmin wide version of core of the cluster (Image Credit as above)
HST image of the core of globular cluster Terzan 9

Terzan 10


Terzan 11 (see
Terzan 5)


Terzan 12


UKS 1


VVV CL001


Whiting 1

Celestial Atlas
GCL 100 - 125 ←Non-GCL Milky Way Globular Clusters→ GCL 1 - 49