M83, also known as the Southern Pinwheel Galaxy, is a barred spiral galaxy approximately 14.7 million light-years distant in the eastern section of Hydra. It's one of the closest barred spirals, a showpiece galaxy and the finest example of its type in the sky. With an apparent magnitude of +7.5, this galaxy is visible with 7x50 or 10x50 binoculars under dark skies as a patch of light with a bright centre.

At a declination of 30 degrees south, M83 is best seen from Southern Hemisphere or equatorial regions during the months of April, May and June. It's the southernmost galaxy in the Messier list and therefore a difficult object from mid-northern latitudes, that never climbs particularly high above the horizon.

Although a relatively bright galaxy, M83 can be tricky to find since it's located in an area of sky devoid of bright stars. It's positioned 6 degrees south of the mid-point of an imaginary line connecting γ Hydrae (mag. +3.0) with π Hydrae (mag. +3.3). M83 was discovered by Nicholas Louis de Lacaille at the Cape of Good Hope in South Africa on February 23, 1752 and was added by Charles Messier to his catalogue on February 17, 1781.

M97, also known as the Owl Nebula, is a famous planetary nebula located in the constellation of Ursa Major. It was discovered by Pierre Mechain on February 16, 1781 and is one of only four planetary nebulae listed in the Messier catalogue. Although not particularly bright at magnitude +9.9, it's a superb object and regarded as one of the most complex examples of its type. The name Owl Nebula was first coined in 1848 by William Parsons the 3rd Earl of Rosse, who noticed owl-like "eyes".

Locating M97 is easy as it's positioned only 2.5 degrees southeast of bright star Merak (β UMa - mag. +2.3). This is the southwest corner star of the bowl of the famous Plough or Big Dipper asterism of Ursa Major. In the same wide field telescope field of view, 50 arc minutes northwest of M97, is barred spiral galaxy M108 (mag. +10.2).

The Owl Nebula is best seen from Northern Hemisphere latitudes during the months of March, April and May. From latitudes north of 35N, it's circumpolar and therefore never sets.

M103 is a small loose but sparkling open cluster of at least 40 stars located among the Milky Way star fields of Cassiopeia. At magnitude +7.4, it's beyond naked eye visibility but an easy binocular target.

M103 was discovered by Pierre Méchain in either March or April of 1781. He reported his discovery to Charles Messier, who would normally take the opportunity to observe the object himself, but this time he didn't probably due to lack of time or unfavourable weather conditions. This cluster along with M101 and M102 were the last objects added by Messier. Items M104 to M110 were included much later during the 20th century.

Messier 103 Open Cluster (credit:- NOAO/AURA/NSF)

M51, also known as the Whirlpool Galaxy, is a grand design spiral galaxy located in the constellation of Canes Venatici. It's one of the most famous galaxies in the sky, appearing face-on when viewed from Earth. At magnitude +8.4, it's relatively bright and visible in binoculars, especially from dark sites. M51 has a much smaller dwarf companion, known as NGC 5195, and together they form the finest and most studied example of an interacting galaxy pair in the sky.

M51 was one of Charles Messier original discoveries on October 13, 1773. His friend Pierre Méchain discovered NGC 5195 on March 20, 1781. Messier described M51, as a faint nebula without stars, that was difficult to see. In his catalogue of 1781, he put M51 and NGC 5195 in the same note and therefore some confusion exists. Was he referring to M51 as the larger galaxy, or did he mean the pair itself. If it was the pair, then the main galaxy should really be referred to as M51A, with NGC 5195 separately known as M51B.

M81, also known as Bode's galaxy, is a large bright spiral galaxy located 11.8 million light-years away in the constellation of Ursa Major. With an apparent magnitude of +6.9, it's easily visible with binoculars and is a superb target for all sizes of telescopes. This galaxy is a striking example of a grand design spiral and exhibits near perfect and well defined spiral arms.

In the same binocular and low magnification telescope field of view as M81 is another prominent galaxy, M82. At mag. +8.4, M82 is fainter than M81 and a very different type of galaxy. It's a starburst galaxy, in which stars are been formed at exceptionally high rates. Also known as the Cigar galaxy, M82 is the prototype object and provides a striking contrast to the near perfect spiral shape of M81. Together, they form a popular visual and imaging target for amateur astronomers.

Both M81 and M82 were discovered by Johann Elert Bode on December 31, 1774. Pierre Mechain independently rediscovered them in August 1779. He reported his observations to Charles Messier who added them both to his catalogue on February 9, 1781.

Finding M81 is not particularly difficult as the famous Plough asterism of Ursa Major can be used as a starting point. First focus on Dubhe (α UMa - mag. +1.8), the northwest corner star of the bowl. The M81 / M82 pair is located 10 degrees to the northwest of this star with M82 positioned 38 arc minutes directly north of M81.

Mercury reaches greatest western elongation on May 17th, when it will be positioned 25.8 degrees from the Sun. This apparition offers an excellent opportunity for observers at southern and tropical latitudes to spot the elusive planet. From such locations, Mercury can be seen low down above the east-northeastern horizon just before sunrise throughout May and until the second week of June. However, from northern temperate locations the planet is not well placed, although from some locations it can be spotted around the time of greatest elongation but always very close to the horizon.

Mercury as imaged by the MESSENGER spacecraft (credit - NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)

Mercury

Mercury reaches greatest elongation west on May 17th when it's positioned 26 degrees from the Sun. The planet is not well placed for observation at northern temperate locations, but from southern latitudes this happens to be the most favourable morning apparition of the year. With an extended period of visibility it can be seen in the morning skies until mid June.

On May 1st, from latitude 35S (approx. equal to Sydney, Cape Town and Santiago), Mercury rises over an hour before the Sun. At magnitude +2.5, binoculars will be required to spot the elusive planet against the bright dawn sky. Positioned a degree from Mercury is fainter Uranus (mag. +5.9). As the month progress the visibility of Mercury improves until greatest elongation west is reached. On May 17th, the planet shines at magnitude +0.5 and appears 15 degrees above the east-northeastern horizon, 45 minutes before sunrise. For the remainder of the month it gradually sinks back towards the horizon. It should be noted that Mercury improves in brightness throughout May and on the 31st it will shine at magnitude -0.3. Brilliant Venus is positioned above Mercury throughout this time.

From mid-northern temperate latitudes, Mercury can be seen for a short while around the time of greatest elongation. However, it's always low down and at best just a few degrees above the horizon.

On May 24th, the thin waning crescent Moon passes 2 degrees south of Mercury.

The annual Eta Aquariids meteor shower, occasionally written as Eta Aquarids, peaks on May 5th / 6th and this year's event is favourable as the waxing gibbous Moon will have set a few hours before sunrise. The shower is best seen in the early morning hours just before sunrise from southern and equatorial regions.

Parent Comet

The parent body for the Eta Aquariids meteor shower is Halley's comet (1P/Halley). This isn't the only annual shower associated with the famous comet, the Orionids in October also originate from the same source. Although Halley has now left the inner Solar System and won't return until 2061, it's worth remembering that every Eta Aquariids meteor is a small part of the famous comet burning up in the Earth's atmosphere.

Halley's Comet (credit:- ESA)

Algol (β Per) is a bright eclipsing binary system located in the northern constellation of Perseus and one of the best-known variable stars in the sky. Often referred to as the "Demon Star", most of the time it shines at mag. +2.1 but every two days, 20 hours and 49 minutes it suddenly dips in brightness to mag. +3.4, remaining dim for about 10 hours before returning to its original state.

Why the change in brightness? The Algol system consists of at least three-stars (β Per A, β Per B and β Per C) with the orbital plane of Algol A and B directly in line with the Earth. The regular dips in brightness occur when the dimmer B star moves in front of and eclipses the brighter A star. There is also an extra dimension in that a secondary eclipse occurs when the brighter star occults the fainter secondary, resulting in a very small dip in brightness that can be detected with photo-electrical equipment.

Algol System (credit:- Dept. of Physics and Astronomy - Univ. of Tennessee at Knoxville)

The annual Lyrids meteor shower peaks during the night of April 21st/22nd and this year's event promises to be a good one, as the 23% illuminated waning crescent Moon in Aquarius, won't significantly interfere. Normally, you can expect to see up to 20 meteors per hour under ideal conditions. In addition, the Lyrids do occasionally produce brilliant fireballs, that streak through the sky and cast shadows as they disintegrate in the Earth's atmosphere.

View just after midnight on April 22, 2017 from northern temperate latitudes (credit:- stellarium/freestarcharts)

Jupiter remains a dazzling object this month and on April 7th the planet is at its best for the year, when opposition is reached. On this day, it will shine at mag. -2.5 and to the naked eye, the largest planet in the Solar System is unmistakable and easily brighter than any night-time star. It's currently located in Virgo, 4 degrees northeast of the constellation's brightest star, Spica (α Vir - mag. +1.0).

At opposition, Jupiter is visible all night long. The planet rises in the east at sunset, reaches its highest point in the sky around midnight before setting in the west at sunrise. It's best seen from equatorial regions, although from northern and southern temperate locations it still reaches a reasonable altitude during late evening and early morning.

Jupiter and Ganymede as seen by Hubble Space Telescope on April 9, 2007 (credit:- NASA, ESA, and The Hubble Heritage Team (STScI/AURA))

Mercury

Mercury reaches greatest eastern elongation (GEE) on April 1st, when it moves out to 19 degrees from the Sun. On this day from mid-latitude northern locations, the innermost planet will shine at mag. -0.2, 10 degrees above the western horizon, 45 minutes after sunset. It remains visible, although fading, until the second week of the month when eventually lost to the bright evening twilight. From mid-northern latitudes, this also happens to be the best evening apparition of the year. However, from southern locations, Mercury is unsuitably placed for observation during this time.

The diagram below shows the altitude of Mercury, 45 minutes after sunset as seen from latitude of 51.5N (e.g. London, England). A similar view exists at other northern temperate latitudes.

Mercury 45 minutes after sunset from mid-latitude northern locations (credit:- freestarcharts)

Algol (β Per) is a bright eclipsing binary system located in the northern constellation of Perseus and one of the best-known variable stars in the sky. Often referred to as the "Demon Star", most of the time it shines at mag. +2.1, but every two days, 20 hours and 49 minutes it suddenly dips in brightness to mag. +3.4, remaining dim for about 10 hours before returning to its original state.

Why the change in brightness? The Algol system consists of at least three-stars (β Per A, β Per B and β Per C) with the orbital plane of Algol A and B directly in line with the Earth. The regular dips in brightness occur when the dimmer B star moves in front of and eclipses the brighter A star. There is also an extra dimension in that a secondary eclipse occurs when the brighter star occults the fainter secondary, resulting in a very small dip in brightness that can be detected with photo-electrical equipment.

Algol System (credit:- Dept. of Physics and Astronomy - Univ. of Tennessee at Knoxville)

Mercury, the innermost planet, is now heading towards greatest eastern elongation (GEE), which it reaches on April 1, 2017. From mid-March, observers at northern-based locations should be able to spot the elusive planet, low down above the western horizon just after sunset. Each subsequent evening it improves in visibility until GEE is reached. After that, Mercury sinks gradually back towards the horizon until about 10 days later when it becomes lost to the bright twilight sky. This also happens to be the best evening apparition of the year from northern locations.

From southern latitudes, Mercury is unsuitably placed for observation this time.

Mercury as seen by the MESSENGER space probe (credit:- freestarcharts)

NGC 6302, also known as the Bug Nebula or Butterfly Nebula, is a bipolar planetary nebula in the constellation of Scorpius. It's an unusual object, complex in structure with an incredibly hot star at its core. At a temperature of 250,000 degrees Celsius, this dying star is one of the hottest known in the galaxy. However, since it radiates predominantly in UV and is shrouded by dust, it's visually challenging to observe.

The discoverer of the Bug Nebula is debatable. Edward E. Barnard observed the planetary in 1880, although some references suggest that James Dunlop may have found it in 1826. The nebula itself shines at mag. of +9.6 and therefore well within the reach of medium size backyard scopes.

NGC 4559 is a spiral galaxy located in the constellation Coma Berenices. At mag. +10.0 it can be spotted with binoculars, but is challenging, requiring dark skies and patience. However, its high surface brightness does somewhat help. The galaxy is a nice telescope target that offers something for all sizes of backyard instruments.

NGC 4559 was discovered by William Herschel on April 11, 1785 and is estimated to be 30 million light-years distant. It's best seen from northern locations during the months of March, April and May.

NGC 4559 (credit:- NASA, ESA, and The Hubble Heritage Team (STScI/AURA))

NGC 3195 is a planetary nebula of mag. +11.5, located in the southern constellation of Chamaeleon. At a declination of -81 degrees, it's the closest bright planetary to the South Celestial Pole and therefore circumpolar from almost the entire Southern Hemisphere. Theoretically, it can also be seen from northern latitudes but only from south of +9 degrees. Even then, from such locations this planetary only scraps above the horizon and is an incredibly difficult, if not impossible, object to spot.

John Herschel discovered NGC 3195 on February 24, 1835. It's number 109 and the final object in the Caldwell catalogue.

NGC 3195 (credit:- NASA, ESA, and The Hubble Heritage Team (STScI/AURA))

Unfortunately, we haven't had a very bright comet for some time now, but there are a number of short-period comets that regularly approach the inner Solar System, and a few of them can even be spotted with binoculars. One of the more interesting is 41P/Tuttle-Giacobini-Kresak. It has an orbital period of 5.4 years and is currently heading back towards perihelion, which it reaches on April 12th. Over the coming months, this comet will be superbly placed in the evening sky for northern-based observers and bright enough to be seen with binoculars. It may even reach naked eye visibility.

Comet 41P/Tuttle-Giacobini-Kresak (credit:- Michael Jäger)

NGC 1097, mag. +9.5, is a face-on barred spiral galaxy located in the southern constellation of Fornax. It's one of the finest barred spirals in the night sky and a nice object for backyard scopes. Through a small refractor, its nucleus appears bright, surrounded by a faint haze. With larger scopes, it's possible to make out the centre bar structure and subtle details in the spiral arms.

NGC 1097 is also classified as a Seyfert galaxy and contains an Active Galactic Nucleus (AGN). At the centre of the galaxy is a huge supermassive black hole of about 140 million times the mass of the Sun. Surrounding the black hole are gases, dust and a prominent ring of hundreds of star-forming regions. New stars are being created in the ring, due to material flowing inwards towards the galaxy centre.

The galaxy is best seen from southern locations during the months of November, December and January. It was discovered by William Herschel on October 9, 1790 and is number 67 in the Caldwell catalogue.

Mercury

Mercury passes through superior conjunction on March 7th, but it's not long before the fast moving planet moves out from the Sun and into the early evening sky. During the second half of the month, it re-appears low down towards the western horizon after sunset from northern locations. For example, on March 31st from London (51.5N) England, Mercury will be positioned 7.5 degrees above the horizon, one hour after sunset.

Between March 15th and 31st, observers should note that although the planets altitude improves slightly each subsequent evening, it brightness dims from mag. -1.5 to -0.4.

From southern temperate latitudes, Mercury is unsuitably placed for observation.

Venus

The current long evening apparition of Venus comes to an end this month. The brightest planet starts March as a dazzling beacon of light, visible after sunset above the western horizon. It shines at mag. -4.8, with an illuminated phase of 16 degrees and an apparent diameter of 47 arc seconds. As the month progresses, Venus falls back towards the Sun, fades in brightness and decreases in phase, but its apparent diameter improves to a maximum of 60 arc seconds. The apparition finally ends on March 25th, when inferior conjunction is reached. However, it's only about a week or so before Venus can be seen again, this time in the early morning sky.

Venus dominates the early evening sky this month. The brightest of planet of all dazzles at mag. -4.8 and remains a brilliant object above the western horizon just after sunset. Given the brilliance of Venus, you might be forgiven for thinking there was only one planet on show during early evening, but there isn't. Currently located in the same region of sky are Mars and Uranus. The difference in brightness between the three planets is striking. Venus is 275x brighter than Mars (mag. +1.3), with Mars 70x brighter than Uranus (mag. +5.9).

A close conjunction occurs on February 27th, when Mars passes less than a degree north of Uranus. The Red planet then acts as a perfect marker for locating the much more distant Uranus. Both objects will be visible in the same binocular field of view and when minimum separation occurs at 8 UT, they will by only 0.6 degrees apart.

The diagrams below show the planetary positions and a telescopic view of the conjunction.

Algol (β Per) is a bright eclipsing binary system located in the northern constellation of Perseus and one of the best-known variable stars in the sky. Often referred to as the "Demon Star", most of the time it shines at mag. +2.1, but every two days, 20 hours and 49 minutes it suddenly dips in brightness to mag. +3.4, remaining dim for about 10 hours before returning to its original state.

Why the change in brightness? The Algol system consists of at least three-stars (β Per A, β Per B and β Per C) with the orbital plane of Algol A and B directly in line with the Earth. The regular dips in brightness occur when the dimmer B star moves in front of and eclipses the brighter A star. There is also an extra dimension in that a secondary eclipse occurs when the brighter star occults the fainter secondary, resulting in a very small dip in brightness that can be detected with photo-electrical equipment.

Algol System (credit:- Dept. of Physics and Astronomy - Univ. of Tennessee at Knoxville)

NGC 4565, also known as the Needle Galaxy, is the finest and brightest example of an edge-on spiral galaxy in the sky. It shines at magnitude +9.5 and therefore is bright enough to be seen with small telescopes. The galaxy is located in the constellation of Coma Berenices. Since positioned at the eastern edge of the sprawling naked eye Coma Star Cluster (Mel 111), it's easy to find.

NGC 4565 was discovered by William Herschel on April 6, 1785. It's number 38 in the Caldwell catalogue and is best seen from northern locations during the months of March, April and May. This spiral is physically large and similar in size to the Andromeda Galaxy (M31).

NGC 4565 (credit:- Ken Crawford)

NGC 4244, also known as Caldwell 26, is an edge-on spiral galaxy located in the constellation of Canes Venatici. With an apparent mag. of +10.0, it can be spotted with small telescopes under dark skies but much easier with larger instruments. The galaxy appears highly flattened, spanning 16 x 2 arc minutes and as a result is often referred to as the Silver Needle galaxy. It's a superb example of an edge-on needle spiral, that's bettered only by NGC 4565 in Coma Berenices.

NGC 4244 was discovered by William Herschel on March 17, 1787. It's part of the M94 Group or Canes Venatici I group of galaxies, which contains at least 24 members. The galaxy is best seen from Northern Hemisphere locations during the months of March, April and May.

NGC 4244 (credit:- NASA, ESA, and The Hubble Heritage Team (STScI/AURA))

During the second half of February, comet Encke will be visible with small telescopes in evening sky above the western horizon just after sunset. This periodic comet, officially designated as 2P/Encke, is now rapidly brightening and will continue to do so until it reaches perihelion on March 10th. On February 17th, it shone at mag. +9.0 and therefore bright enough to be seen with small/medium size scopes. By the end of month, it's expected to have improved to mag. +7.3 and within binocular range. However, it will be a challenging binocular object - not because of its magnitude - but due to its low altitude at dusk.

Comet Encke (2P/Encke) as imaged by the Spacewatch Telescope on Kitt Peak in 1994 (credit:- JPL/Jim Scotti)

NGC 7331, mag. +9.5, is a spiral galaxy about 50 Million light-years distant in the constellation Pegasus. It's the brightest member of the NGC 7331 Group of galaxies, which is also known as the Deer Lick Group. This small collection - also referred to as the "fleas" - contains four other members, NGC 7335, NGC 7336, NGC 7337 and NGC 7340.

NGC 7331 is visible in large binoculars and small telescopes. From our perspective, it's inclined and appears somewhat like a miniature version of the Andromeda Galaxy (M31). Indeed, the two galaxies are physically very similar in size and shape, although NGC 7331 is about 20x more distant. Of all the Pegasus galaxies visible in backyard scopes, NGC 7331 is the finest.

William Herschel discovered NGC 7331 on September 5, 1784. The galaxy is number 30 in the Caldwell catalogue and is one of the brighter galaxies not included in the Messier catalogue. It's best seen from northern temperate locations during the months of July, August and September.

NGC 7331 (credit:- NASA, ESA, and The Hubble Heritage Team (STScI/AURA))

NGC 4889 is a supergiant elliptical galaxy in the constellation of Coma Berenices. It's one of the principal members of the Coma Cluster, a large cluster of a least 1,000 galaxies located 335 million light-years distant. This group of galaxies is comparable to the Virgo Cluster but six times further away.

NGC 4889 lies at the centre of the Coma Cluster, a region it dominates along with another supergiant elliptical, NGC 4874. The Coma Cluster is also known as Abell 1656 and together with the Leo Cluster (Abell 1367) they are the major constituents of the Coma Supercluster. With an apparent mag. of +11.5, NGC 4889 is the brightest Coma cluster member and can be glimpsed with just a 100mm (4-inch) refractor, which is remarkable considering how far away it is.

Many amateur astronomers like to push telescopes to test their deep space distance records. The obvious starting point is the Messier catalogue and the most distant Messier galaxy is M109, at 83.5 Million light-years. To go deeper still you need to search elsewhere and the Caldwell catalogue has a few good examples. One of them is NGC 4889 and it's one of the most distant galaxies easily visible with backyard scopes. The current estimate has it at 308 Million light-years.

Periodic comet 45P/Honda-Mrkos-Pajdusakova passed close by the Earth on February 11, 2017. On this day, it moved to within 12.6 million kilometres or 7.8 million miles of our planet, which in astronomical terms was just a stone's throw away. At closest approach, the comet shone at mag. +6.5 and was visible with binoculars. However, soon it will dramatically fade as it heads towards the outer Solar System. As a result, the third week of February offers the last real good chance to catch a glimpse, until it returns in 5 years time.

45P/Honda-Mrkos-Pajdusakova as imaged on October 1, 2011 (credit:- Martin Mobberley - www.martinmobberley.co.uk)

NGC 1275, also known as Perseus A, is a Seyfert galaxy in the constellation Perseus. It's lies at the centre of the Perseus cluster of galaxies (Abell 426) and is the group's dominant member. At 230 million light-years distant, it's way beyond the Local Group but can be spotted in medium size backyard scopes under dark skies and good seeing conditions. The galaxy shines at apparent mag. +11.7.

NGC 1275 is a strong radio and X-ray source that produces peculiar emission lines in its nucleus. It's listed as entry 3C 84 in the 3rd Cambridge Catalogue of Radio Sources and Carl Seyfert include it in his original list of active galaxies. NGC 1275 is actually a complex system consisting of a main galaxy and a high velocity system (HVS). Tidal interactions between the two objects result in large amounts of dust disruption, gas stripping and star formation. In addition, tidal forces send existing gas and dust swirling into the supermassive black hole at centre of the main galaxy, resulting in the powerful X-ray and radio wave emissions.

NGC 1275 was discovered by William Herschel on October 17, 1786.

IC 59 and IC 63 are faint reflection and emission nebula located in the northern constellation of Cassiopeia. They are challenging objects to spot with telescopes for a number of reasons. Both nebulae are faint at apparent mag. +10, they have extremely low surface brightness and surround bright variable star gamma Cas (γ Cas). This remarkable star is partly unstable and is known as a "shell star". It currently shines at mag. +2.15, making it the brightest star in Cassiopeia.

IC 59 and IC 63 are 610 light-years distant. From our perspective, IC 59 is located on the northern side of gamma Cas and IC 63 to the northeast. Spatially the nebulae are roughly 3 light-years from gamma Cas, although IC 63 is slightly closer to the star. As a result, it's appears mostly red due to a dominance of H-alpha emission, whereas IC 59 exhibits much less H-alpha emission and appears mostly blue due to dust reflected starlight.

IC 59 and IC 63 (credit:- Ken Crawford, Rancho Del Sol Observatory (www.imagingdeepsky.com))

IC 2944, mag. +4.5, is a naked eye open cluster and associated emission nebula located in Centaurus. It was born 7.9 million years ago. The cluster and nebula are positioned at the southeast edge of mag. +3.1 star, lambda Centauri (λ Cen). Indeed, it's sometimes referred to as the Lambda Centauri Nebula, although the star has nothing at all to do with it. Lambda Centauri is an interloper, a foreground star that just happens to appear in the same line of view. For comparison, it's 420 light-years distant while IC 2944 lies 6,500 light-years away.

The emission nebula surrounds the cluster. It's a cloud of dust and gas some 70 to 77 light-years in diameter, located between 5,800 and 6,500 light-years away. The nebula itself is almost featureless but contains a small group of dense, opaque dark clouds known as Bok globules. They are associated with star formation, although to date no evidence has been found of star formation in any of these Bok globules. The nebula is also called the Running Chicken Nebula. This strange nickname comes from the bird-like shape of its brightest region.

IC 2944 is best seen from the Southern Hemisphere during the months of March, April and May. From many southern locations it's circumpolar and therefore never sets. It can't be seen from northern temperate locations.

NGC 3766, also known as the Pearl Cluster, is a superb open cluster in Centaurus. At magnitude +5.3, it's faintly visible to the naked eye but challenging to spot against the numerous stars of the background Milky Way. The cluster was born in the Carina molecular cloud, a vast star-forming region that lies at approximately between 6,500 and 10,000 light-years distant. It includes the barely-stable star eta Carinae (η Car), which one-day will explode as a spectacular supernova.

NGC 3766 is a nice binocular target, a wonderful sight through telescopes and one of the jewels of the southern sky. With a declination of 61S, it's best seen from southern latitudes during the months of March, April and May. From many southern towns and cities, the cluster is circumpolar and therefore never sets. However, from northern locations above 29N it never rises above the horizon.

Nicholas Louis de Lacaille discovered NGC 3766 on March 5, 1752.

NGC 1851 is a globular cluster in the southern constellation of Columba that's easily visible with binoculars. It's an unusual cluster since it was probably a former member of the Canis Major Dwarf galaxy. This dwarf galaxy and Local Group member was discovered in 2003.

James Dunlop, a Scottish astronomer based in Australia, discovered NGC 1851 on May 29, 1826. It shines at mag. +7.3 and spans 11 arc minutes of sky, making it the brightest and largest deep sky object in Columba.

The globular is best seen during the months of December, January and February. From northern temperate locations it appears low down, apart from latitudes above 50N where it's not even visible at all. The object is number 73 in the Caldwell catalogue.

NGC 1851 (credit:- NASA, ESA, and The Hubble Heritage Team (STScI/AURA))

NGC 6541, also known as Caldwell 78, is a globular cluster in the southern constellation of Corona Australis. It shines at mag. +6.3 and therefore just beyond naked eye visibility, but easily seen with binoculars and small scopes. Although often overlooked and not as spectacular as the great southern showpiece globulars, it's still a fine object in its own right.

NGC 6541 was discovered by Niccolò Cacciatore at the Palermo Astronomical Observatory, Sicily, on March 19, 1826. James Dunlop independently found it a few months later on July 3, 1826. The cluster is best seen from southern regions during the months of June, July and August. From locations north of latitude 47N, it never rises above the horizon.

NGC 6541 (credit:- NASA, ESA, and The Hubble Heritage Team (STScI/AURA))

NGC 6934, also known as Caldwell 47, is a 9th magnitude globular cluster located in Delphinus. Backyard scopes show a fuzzy disk of nebulosity, about 5 arc minutes in diameter with a brighter core. The globular is not visually spectacular, but that's due to distance and not intrinsic brightness. At 50,000 light-years, it's one of the more remote globulars easily seen with amateur scopes.

William Herschel discovered NGC 6394 on September 24, 1785. He classified it as a "bright nebula" but wasn't able to resolve any stars.

The cluster is best seen during the months of July, August and September. It has a spatial diameter of 120 light-years and is estimated to contain about 250,000 stars. It's believed to be around 10 billion years old.

NGC 6934 (credit:- NASA, ESA, and The Hubble Heritage Team (STScI/AURA))

NGC 6025, mag. +5.1, is a naked eye open cluster located in the southern constellation of Triangulum Australe. It's essentially a southern-based object that's a nice target for binoculars and small scopes. From all locations below 30S, NGC 6025 is circumpolar and therefore never sets. The cluster can also be seen from northern locations, although from latitudes greater than 30N it never rises above the horizon.

NGC 6025 is 2,500 light-years distant and is best seen between the months of May and July. It was discovered by Abbe Lacaille during his 1751 / 1752 South African tour.

NGC 6025 (credit:- Roberto Mura)

Sky Highlights - May 2017

Mercury
Mercury reaches greatest elongation west on May 17, 2017

Meteor Shower
Eta Aquariids meteor shower peaks on May 5th and 6th, 2017

The Planets
This Month's Guide

Algol Minima
Algol eclipse dates and times for May 2017

Northern Hemisphere
Evening
West:- Mars (mag. +1.6)
South:- Jupiter (mag. -2.4)
Midnight
Southwest:- Jupiter
Southeast:- Saturn (mag. +0.2)
Morning
South:- Saturn
East:- Venus (mag. -4.7)

Southern Hemisphere
Evening
West:- Mars
North:- Jupiter
Midnight
Northwest:- Jupiter
North:- Saturn
Morning
Northwest:- Saturn
East:- Venus, Mercury (mag. +2.5 to -0.3), Neptune (mag. +7.9)

Deep Sky
Naked eye / binoculars:-
Melotte 111 - Mel 111 - The Coma Star Cluster (Open Cluster)
Messier 44 - M44 - The Praesepe (Open Cluster)

Telescopes:-
Messier 67 - M67 - Open Cluster
Messier 51 - M51 - The Whirlpool Galaxy (Spiral Galaxy)
Messier 97 - M97 - The Owl Nebula (Planetary Nebula)
Messier 101 - M101 - The Pinwheel Galaxy (Spiral Galaxy)
Messier 65 – M65 – Spiral Galaxy
Messier 66 - M66 - Intermediate Spiral Galaxy
Messier 95 - M95 - Barred Spiral Galaxy
Messier 96 - M96 - Intermediate Spiral Galaxy
NGC 4244 - Spiral Galaxy
NGC 4565 - Needle Galaxy - Spiral Galaxy

Guides / Star Charts

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