Globular Cluster 47 Tucanae

NGC 104, also known as 47 Tucanae, is a prominent globular cluster located in the constellation Tucana in the southern sky. It is one of the largest globular clusters and the second brightest in the Milky Way galaxy, making it easily visible to the naked eye from dark locations. First recorded in 1751 by Lacaille in his deep-sky catalogue, it was later identified as number "47" in Johann Elert Bode's catalogue who reorganized Lacaille's listed objects by constellation and Right Ascension, a number which is widely used still today. 47 Tucanae is distinguished by its compact and intensely bright core. With millions of stars concentrated in about 120 light-years of diameter, it is one of the most massive globular clusters in the galaxy. It is estimated to be about 11.5 billion years old, making it one of the oldest known globular clusters in the Milky Way. Despite its proximity to the Small Magellanic Cloud, which appears adjacent to it in the sky, 47 Tucanae is over fifteen times closer. Takahashi CCA250 (250/f5) - ZWO 6200MM - R (200m) G (240m) B (270m) - Osservatorio AMT (A.Lau/M.Lorenzi/T.Tse), Río Hurtado, Cile. Elaborazione immagini M.Lorenzi.

NGC 6520 & Barnard 86 Area

Did you ever have a day when it felt like a dark cloud was following you around? For the open cluster of stars NGC 6520, every day is like this. On the left of the above picture are many of NGC 6520's bright blue stars. They formed only millions of years ago - much more recently than our ancient Sun which formed billions of years ago. On the right is an absorption nebula, molecular cloud Barnard 86, from which the stars of NGC 6520 surely formed. This nebula contains much opaque dust that blocks light from the many stars that would have been visible in the background. Surrounding NGC 6520 is part of the tremendously dense starscape in the bulge of our Milky Way Galaxy, the extended halo of stars that surrounds the center of our Galaxy. NGC 6520 spans about 10 light years and lies about 5500 light years away toward the direction of Sagittarius. (Text adapted from APOD). Apo TEC140 (140/f7.2) - FLI Proline 16803 - L (240m) R (90m) G (90m) B (90m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia

M41 (aka Little Beehive) in Canis Major

Messier 41 is an open cluster in the Canis Major constellation, first discovered by Giovanni Batista Hodierna in 1654 even if was perhaps known to Aristotle already in 320 BC. It lies about four degrees south of Sirius, covering an area around the size of the full Moon while its actual diameter is estimated to be between 25 and 26 light years. Easy spotted with naked eyes under rural skies, it is a beautiful object in binoculars, with about 25 bright stars and many fainter ones scattered in a field as large as the full Moon, including several red giants, the brightest having an apparent magnitude of 6.3 near the cluster's center. Much less known to most is that the milky way surrounding M41 is rich of faint HII emission that I was able to capture in the image above thanks to a quite long CCD integration through a Ha filter. Apo TEC140 (140/f7.2) - FLI Proline 16803 - Ha (360m) R (90m) G (80m) B (90m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia

NGC 2451 and NGC 2477 in Puppis

NGC 2451 (right) and NGC 2477 (left) are a gorgeous couple of clusters in the costellation of Puppis. NGC 2477 is a glorious open cluster grouping over 300 members in an area almost as extensive as the full Moon. It has been called "one of the top open clusters in the sky", like a highly resolved globular cluster without the dense center characteristic of globular clusters. Although it is smaller than M46 (also an open cluster in Puppis), it is richer and more compact. It was discovered by Abbé Lacaille in 1751. NGC 2451 is far closer and sparser compared to his compact neighbor and has around 40 stars well dispersed with its brightest star being c puppis, a yellowish giant of magnitude 3,6. The cluster was discovered by Giovanni Batista Hodierna in 1654. Only in recent years it was confirmed that NGC 2451 was actually two open clusters that lie along the same line of sight, labeled NGC 2451A and NGC 2451B, located at distances of 600 and 1,200 light-years respectively. The sky background is filled with faint Hydrogen emission of the GUM Nebula, giving the whole area a nice contrast. Named after Colin Gum, a late Australian astronomer, the Gum Nebula is an huge emission region that covers over 40° of the sky. It is believed to be a still expanding remnant (or remnants) of one, or more, supernovae that exploded millions of years ago. Apo TEC140 (140/f7.2) - FLI Proline 16803 - 2 panels mosaic, each panel Ha (300m) L (170m) R (90m) G (90m) B (90m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia

The Pleiades (M45)

Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters. The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. Quite evident in the above photograph are the blue reflection nebulae that surround the brighter cluster stars. Low mass, faint, brown dwarfs have also been found in the Pleiades. (Text adapted from APOD). This object was imaged from my southern Australian observatory, with a maximum elevation from the horizon between 30 and 35 degrees.. Apo TEC140 (140/f7.2) - FLI Proline 16803 - L (330m) R (120m) G (150m) B (150m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia

The Butterfly Cluster (M6)

To some, the outline of the open cluster of stars M6 resembles a butterfly. M6, also known as NGC 6405, spans about 20 light-years and lies about 2,000 light years distant. M6 can best be seen in a dark sky with binoculars towards the constellation of Scorpius, coving about as much of the sky as the full moon. Like other open clusters, M6 is composed predominantly of young blue stars, although the brightest star is nearly orange. M6 is estimated to be about 100 million years old. Determining the distance to clusters like M6 helps astronomers calibrate the distance scale of the universe (text adapted from APOD). Apo TEC140 (140/f7.2) - FLI Proline 16803 - Ha (270m) R (100m) G (120m) B (120m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia

M7: Ptolemy Cluster

M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of the Scorpion (Scorpius). M7 contains about 100 stars in total, is about 200 million years old, spans 25 light-years across, and lies about 1000 light-years away. The M7 star cluster has been known since ancient times, being noted by Ptolemy in the year 130 AD. Also visible are a dark dust cloud and literally millions of unrelated stars towards the Galactic center (text adapted from APOD). Apo TEC140 (140/f7.2) - FLI Proline 16803 -R (60m) G (50m) B (60m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia

Omega Centauri: The Brightest Globular Cluster

This huge ball of stars predates our Sun. Long before humankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy. Of the 200 or so globular clusters that survive today, Omega Centauri is the largest, containing over ten million stars. Omega Centauri is also the brightest globular cluster, at apparent visual magnitude 3.9 it is visible to southern observers with the unaided eye. Cataloged as NGC 5139, Omega Centauri is about 18,000 light-years away and 150 light-years in diameter. Unlike many other globular clusters, the stars in Omega Centauri show several different ages and trace chemical abundances, indicating that the globular star cluster has a complex history over its 12 billion year age (text adapted from APOD). Apo TEC140 (140/f7.2) - FLI Proline 16803 - L (430m) R (90m) G (90m) B (90m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia

M46 & M47: Star Clusters Young and Old

Many stars form in clusters. Galactic or open star clusters are relatively young swarms of bright stars born together near the plane of our Milky Way Galaxy. Separated by about a degree on the sky, two nice examples are M46 (lower left) 5,400 light-years in the distance and M47 (upper right) only 1,600 light-years away toward the nautical constellation Puppis. Around 300 million years young M46 contains a few hundred stars in a region about 30 light-years across. Aged 80 million years, M47 is a smaller but looser cluster of about 50 stars spanning 10 light-years. But this portrait of stellar youth also contains an ancient interloper. The small, colorful patch of glowing gas in M46 is actually the planetary nebula NGC 2438 - the final phase in the life of a sun-like star billions of years old. NGC 2438 is estimated to be only 3,000 light-years distant and likely represents a foreground object, only by chance appearing along our line of sight to youthful M46 (text adapted from APOD). Apo TEC140 (140/f7.2) - FLI Proline 16803 - R (120m) G (120m) B (120m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia

The Wishing Well Cluster (NGC 3532)

NGC 3532, also known as the Wishing Well Cluster, is an open cluster in the constellation Carina and one of the Southern Sky's finest Jewels. It got the name because through a telescope's eyepiece it appears like dozens of silver coins twinkling at the bottom of a wishing well. NGC 3532 was discovered by Nicholas Louis de Lacaille on January 25, 1752 from South Africa, and cataloged as Lacaille II.7. About 1,300 light years distant and consisting of approximately 150 stars of 7th magnitude & fainter, NCG 3532 was the first target ever observed by the Hubble Space Telescope on May 20, 1990. It lies between the Southern Cross constellation and larger but fainter “False Cross” asterism with X Carinae the nearest star right next to the cluster but not a member and Eta Carinae & its famous nebula not too far away along with a bunch of other nearby deep sky objects (text adapted from Wikipedia). Apo TEC140 (140/f7.2) - FLI Proline 16803 - Ha (160m) R (60m) G (60m) B (60m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia

The Southern Pleiades (IC 2602)

The Southern Pleiades IC 2602 (aka the Theta Carinae Cluster or Caldwell 102) is an open cluster in the constellation Carina. It was discovered by Abbe Lacaille in 1751 from South Africa and can be seen with the naked eye. Theta Carinae, the brightest star within the open cluster, is a third-magnitude star with an apparent magnitude of +2.74. Like its northern counterpart in Taurus, the Southern Pleiades spans a sizeable area of sky, approximately 50 arcminutes, that at an estimate distance of 480 light-years makes its real size about 14 light years. The small cluster visible at the bottom of the image is Lorenzin-Melotte 101. At an estimated distance of 6,800 light years, it is 14 times more distant than IC 2602 and has a diameter of roughly 25 light years. So if the Southern Pleiades cluster were removed to the distance of Melotte 101 it would only look 60% as wide as the latter. The long Ha exposure added to the image reveals some faint nebulosity permeating the whole area, a feature very seldom imaged (text adapted from Wikipedia). Apo TEC140 (140/f7.2) - FLI Proline 16803 - Ha (540m) R (130m) G (90m) B (120m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia

Dusty Ophiucus

What slithers there? The dark winding lanes visible in part of the constellation Ophiuchus belong to the Snake Nebula. The Snake Nebula is a series of dark absorption clouds made up of Interstellar dust. Interstellar dust grains - composed predominantly of carbon - absorb visible starlight and reradiate much of it in the infrared. This absorption causes stars behind the clouds to be obscured from view, hence the appearance of starless voids on the sky. (text adapted from APOD). In this celestial portrait are visible several dark nebulae cataloged by Barnard: B72, B78 (part of the Pipe Nebula), B272 (the dark "scorpion" above the snake), B63 etc. Click here for a detailed chart of this FOV (from the original plate n.20 of Barnard catalog) Pentax 67 EDIF 300mm f/4 - FLI Proline 16803 - R (30m) G (30m) B (30m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia