Mercury reached inferior conjunction on January 30th and consequently was too close to the Sun to be observable. However, since the planet moves fast it takes less than two weeks before it reappears as a morning object for observers at tropical and Southern Hemisphere latitudes. Mercury then climbs higher in the sky each subsequent morning until peaking on February 24th, when it reaches greatest elongation west (26.7 degrees from the Sun). From northern temperate latitudes, the angle of the ecliptic is not favourable and during this time the planet is unsuitably placed for observation.
As often is the case with Mercury apparitions, one hemisphere of the Earth is favoured over the other. On this occasion it's the Southern Hemisphere with the added bonus that this also happens to be the most favourable morning apparition of the year. With an extended period of visibility the opportunity to spot the illusive planet over the next few weeks is superb.
For example, from latitude 35S (approx. equal to Sydney, Cape Town and Santiago) Mercury (mag. +0.3) will appear 13 degrees above the eastern horizon 45 minutes before sunrise on February 14th. The planets altitude continues to improve slightly each subsequent morning until February 24th when it peaks at 16 degrees above the horizon. Mercury shines at mag. 0.0 on this day.
The brightest comet that can be seen in the night sky at the moment is comet Lovejoy (C/2014 Q2). At the end of December it was a superb binocular/telescope sight, faintly visible to naked eye as it moved through the southern constellations of Columba and Lepus. The comet then continued to brighten until peaking at magnitude +3.9 during closest approach to the Earth on January 7th. On this day it was 0.469 AU (70.2 million km or 43.6 million miles) distant from our planet and although the bright Moon somewhat interfered, the comet was easily visible with binoculars and small scopes as a large hazy circular patch of light. When imaged or photographed it displayed a long thin wispy green tail that extended over 10 degrees in length.
Now fading Lovejoy remains excellently placed for observation from the Northern Hemisphere during February. As the month progresses it's expected to fade from magnitude +4.8 to +6.3. For the first part of February the comet should still be visible to the naked eye and will remain an easy binocular and small telescope target for quite sometime to come.
From southern latitudes the comet maybe glimpsed low down above the northern horizon at the start of February. However, for these observers it isn't long before it disappears from view completely. On January 30, Lovejoy reaches perihelion (closest point to the Sun) at 1.2908 AU equivalent to 193.1 million kilometres or 120 million miles.
Jupiter the Solar System's largest planet has been well placed for observation for a few months now as it moves retrograde amongst the stars of Leo. Since the end of last year the planet was visible in early evening, appearing as a spectacular dazzling object. On February 6th, Jupiter is at its best for 2015 when the giant planet reaches opposition. On this day, it will rise in the east as the Sun sets and then set in west as the Sun re-rises on the opposite side of the sky. With a magnitude of -2.6, the "King of the planets" is unmistakable and far brighter than any nighttime star.
Jupiter stars the month in western Leo before crossing the constellation boundary into Cancer on February 4th where it remains for the rest of the month. Positioned 12 degrees southeast of Jupiter is Regulus (α Leo - mag. +1.4) the brightest star in Leo with the Gemini twin stars of Castor (α Gem - mag. +1.6) and Pollux (β Gem - mag. +1.2) located 25 degrees northwest of Jupiter. Although all three stars are bright, Jupiter far outshines them being about 35x brighter than Pollux and 40x brighter than Castor and Regulus.
The current northern declination of Jupiter slightly favours Northern Hemisphere observers, but even from southern latitudes where the planet appears lower down it's still unmistakable due to its brightness.
NGC 4236 is a tenth magnitude barred spiral galaxy in Draco that's visible through small telescopes, although best seen with larger instruments. The galaxy was discovered by German born British astronomer William Herschel on April 6, 1793 and is a member of the Ursa Major or M81 group of galaxies that contains at least 34 galaxies, including spectacular M81 (Bode's galaxy) and M82 (Cigar galaxy).
NGC 4236 is located in the far northern constellation of Draco about 15 degrees north of the seven stars that form the famous "Plough" or "Big Dipper" asterism of Ursa Major. The galaxy is positioned two-thirds of the way along an imaginary line connecting stars lambda Dra (λ Dra - mag. +3.8) and kappa Dra (κ Dra - mag. +3.9). Star HD 106574 (mag +5.7) is 0.75 degrees directly north of NGC 4236.
Due to its high northerly declination, NGC 4236 is a Northern Hemisphere object. The best months to look for it are March, April or May although from most northern locations it's visible all year round and never sets. It can be seen from the Southern Hemisphere but only from latitudes north of 20 degrees south and even then appears low down above the northern horizon at best.
The New Year is off to a fine start for astronomers with comet Lovejoy (C/2014 Q2) now bright enough to be seen with the naked eye. When it was discovered on August 17, 2014 the comet was predicted to reach about magnitude +8 and hence within binocular range but too faint to be seen with the naked eye. However, Lovejoy has exceeded expectations and is now bright enough to seen without optical aid from a reasonably dark site.
On January 7th, Lovejoy reached closest approach to Earth at 0.469 AU (70.2 million km or 43.6 million miles). On this day it shone at magnitude +4.5 in the constellation of Eridanus just west of magnificent Orion. Since it was two days after full Moon, spotting the comet with the naked eye was difficult but easy with binoculars, appearing as obviously non-stellar hazy patch of light. Photographically, Lovejoy appeared green in colour with a long thin tail. Prospects for the remainder of the month are even better, the Moon has now past full and although the comet is now receding from Earth, it should remain within naked eye visibility for a few weeks to come.
NGC 2362 is a small compact young open cluster in Canis Major that surrounds bright star Tau Canis Majoris (τ CMa - mag. +4.37). This attractive grouping of 60 stars is packed into an area spanning just 6 arc minutes of apparent sky. The apparent magnitude of the cluster is given as +4.1, however the value is misleading as its skewed significantly because of the brilliance of τ CMa. The remaining members of NGC 2362 are much fainter, the brightest being of 7th magnitude.
Finding NGC 2362 is not difficult. It's located 2.75 degrees northeast of Wezen (δ CMa - mag. +1.83) the third brightest star in Canis Major. Sirius (α CMa) the brightest star in the night sky (mag. -1.46) is positioned 11 degrees to the northwest. Tau CMa a spectroscopic multiple system that shines with a combined light of tens of thousands times that of the Sun is the stand out cluster member and bright enough to be seen with the naked eye. For comparison, the Sun at the same distance would shine at a feeble magnitude +15.
NGC 2362 was discovered by Giovanni Batista Hodierna sometime before 1654 and then re-discovered by William Herschel on March 4, 1783. It's best seen from southern latitudes during the months of December, January and February.
NGC 2261 is a curious variable reflection nebula in Monoceros that's known as Hubble's Variable Nebula. It was discovered by William Herschel in 1783 and is illuminated by variable star R Monocerotis (R Mon). The nebula is unusual in that it changes shape over just a period of days and can vary by up to 2 magnitudes in brightness. The variations are believed to be due to periodic changes in the amount of dust surrounding R Mon, thus affecting the amount of light that reaches us. With an apparent magnitude of +9.0, it can be spotted with binoculars under dark skies.
The variability of R Mon (between magnitudes +10 and +12) was discovered at the Athens Observatory in 1861 but it wasn't until 1916 that Edwin Hubble realised that the nebula also changes in brightness. The variations are such that even on images taken days apart structural changes can be observed.
NGC 2261 was chosen as the "first light" photograph on January 26, 1949 for the 200-inch (5.1 m) Hale reflecting telescope under the direction of American astronomer Edwin Powell Hubble. At the time, the newly constructed Hale telescope was the largest telescope in the World and remained so until 1976.
Mercury reaches greatest elongation east on January 14th (19 degrees @ mag. -0.7). From northern temperate and equatorial locations the closest planet to the Sun can be glimpsed low down above the southwestern horizon for about the first 3 weeks of the month, with the visibility period about a week less for those located further south.
This is not a particular good elongation of Mercury; even on the day of greatest elongation it appears only 5 degrees above the horizon 45 minutes after sunset. From about January 9th to 12th, much more brilliant Venus is close by and aids in finding its more illusive neighbour.
Mercury's magnitude fades from -0.8 to 0.0 between January 1st and 20th. The planet reaches perihelion on January 21st when it's located 0.308 AU (approx. 46.1 million kilometres or 28.6 million miles) from the Sun. On January 30th, Mercury passes inferior conjunction.
During January, Venus becomes a brilliant evening object for observers located at northern latitudes. At the beginning of the month the planet is visible for about 45 minutes above the southwestern horizon but by months end the visibility increases noticeably with the planet setting over 2 hours after the Sun. At magnitude -3.9, Venus is unmistakable, a dazzling beacon of light that's so bright it's often reported as a hovering UFO! Venus is also visible from southern temperate latitudes this month but always appears low down above the western horizon. It sets just over 1 hour after the Sun.
The Quadrantids meteor shower peaks on night of January 3/4, 2015. At maximum around 120 meteors per hour can be seen, which is comparable to the other great annual meteor showers the Perseids and the Geminids. However, the Quadrantids has a narrow peak activity window lasting only a few hours and consequently is not as well observed. Prospects for this year's event are not so good as the almost full Moon in northern Orion will significantly interfere. Therefore, if you can glimpse even just a few of these illusive meteors it will be a fine start to the new astronomical year!
Meteor showers are named after the constellation (or nearby star) where the radiant is located, but you may have difficulty figuring out the associated region for the Quadrantids; the reason is that the constellation no longer exists.
Today, the Quadrantids radiant is located in the northern constellation of Boötes, not far from the tail of Ursa Major. When the shower was discovered by Adolphe Quetelet of the Brussels Observatory in the 1830s, the radiant was located in the now obsolete constellation of Quadrans Muralis, hence the name "The Quadrantids".
As we head into the New Year, comet Lovejoy (C/2014 Q2) remains superbly placed for observation as it continues to brighten into January. The comet that was discovered by Australian amateur astronomer Terry Lovejoy has so far exceeded expectations and has been well seen from southern and tropical latitudes. For most of December, although Lovejoy was just beyond naked eye visibility it was an easy binocular and small telescope target, moving northwesterly through the southern constellations of Puppis, Columba and Lepus. By Christmas Day, Lovejoy had brightened to magnitude +5.4 and therefore within naked eye visibility. It's expected to peak at about magnitude +4.5 during the middle of January.
Northern Hemisphere based observers haven't had much of a look at Lovejoy but that's going to change. During the last days of December it can be spotted low down above the southern horizon with visibility continually improving as it climbs higher each subsequent evening. From southern latitudes, Lovejoy remains observable in excellent condition until late January.
Lynx is home to the fascinating globular cluster NGC 2419. Although visually faint and small what makes NGC 2419 special is its distance; at 275,000 light-years it's one of the furthest known Milky Way globulars. In fact, twentieth century American astronomer Harlow Shapley nicknamed it "The Intergalactic Tramp" believing it to have possibly broken away from the Milky Way and headed off into deep inter galactic space. However, recent observations indicate Shapley hypothesis was incorrect and NGC 2419 is still gravitationally bound to the Milky Way just moving in a highly eccentric orbit.
NGC 2419 or Caldwell 25 was discovered by William Herschel on December 31, 1788. It's located 275,000 light-years from the Solar System and about 300,000 light-years from the galactic centre, almost twice as far away as the Large Magellanic Cloud. At such a distance it's estimated it will take about 3 billion years to complete a single orbit around the centre of the galaxy.
NGC 2419 is positioned 7 degrees north and slightly east of Castor (α Gem - mag. +1.58) the second brightest star in Gemini. About 4 arc minutes west of NGC 2419 is a mag. +7.2 star with a double star of mag. +7.9 a few more arc minutes further west. Even Herschel with his super telescopes of the time couldn't resolve NGC 2419 into stars. William Parsons, the 3rd Earl of Rosse, using his 72-inch (1.83 m) reflecting telescope at Birr Castle in Ireland - the largest optical telescope in the world at the time - was first the first to do so in 1850.
The major meteor event in December is the Geminids but there's another shower later in the month that's doesn't make quite as many headlines but on occasions can be quite good - the Ursids.
With the radiant located close to the North Pole Star, the Ursids are a Northern Hemisphere shower. They are much less dramatic than the Geminids with only about 10 meteors per hour visible but on several previous occasions they have shown significant bursts of activity and a re-occurrence may happen anytime.
This year's Ursid peak occurs on the night of December 22nd/23rd and the good news the Moon is new and therefore won't interfere.
The comet that sources and therefore responsible for the Ursid meteor shower is 8P/Tuttle (also known as Tuttle's Comet or Comet Tuttle). It has a period of 13.6 years and during the last perihelion on January 27, 2008 it was visible telescopically. The comet passed Earth at a distance of 0.25282 AU (37,821,000 km or 23,501,000 miles) on January 1, 2008 and anticipation was high that the 2007 and 2008 showers may produce much increased activity, but this was not to be. In the end only a small increase was noted.
NGC 752 is a large spawling open cluster in the constellation of Andromeda. With an apparent magnitude of +5.7, it's visible to the naked eye from a dark site appearing as a large unresolved fuzzy patch of light. The cluster is one of the finest large open clusters in the sky and contains over 70 stars spread across a huge 1.25 degrees of apparent sky. Due to its size, NGC 752 is best observed with binoculars or through wide field telescopes at low powers.
NGC 752 is located 5 degrees south and slightly west of outstanding double star Almach (γ And - mag. +2.1) the third brightest star in the constellation. It was discovered by Caroline Herschel on September 29, 1783 although it was probably observed sometime before 1654 by Italian astronomer Giovanni Battista Hodierna. Caroline's brother William Herschel subsequently added it to his catalogue a couple of years later. It's best seen from northern latitudes during the months of October, November and December.
NGC 2360 is an open cluster visible with binoculars in the constellation of Canis Major. It was the first deep sky discovery made by Caroline Herschel - the younger sister of William Herschel - on February 26, 1783. She described it as "a beautiful cluster of pretty compressed stars near 1/2 degree in diameter." It's also known as Caroline's Cluster, Caldwell 58 and Melotte 64.
William included the cluster in his 1786 catalogue of 1000 clusters, crediting his sister as the discoverer. At magnitude +7.2, NGC 2360 is not visible to the naked eye but it's an easy binocular object and a fine sight through small telescopes. The cluster is positioned 8 degrees east-northeast of the brightest star in the night sky Sirius (α CMa - mag. -1.47) and lies 3.5 degrees directly east of gamma CMa (γ CMa - mag. +4.1). At the western edge of NGC 2360 is an unrelated star, HD 56405 (mag. +5.5).
NGC 457 is the brightest open cluster in Cassiopeia and one of the finest objects of its type in the northern sky. At magnitude +6.4, it's just beyond naked-eye visibility but easily seen with binoculars and a beautiful sight through telescopes. The brightest cluster stars are arranged in prominent lines and curves lines appearing to resemble an Owl shape, hence the popular name "the Owl Cluster". It's located 7,900 light-years distant.
NGC 457 was discovered by William Herschel in 1787. Finding the Owl Cluster is easy; it's positioned two degrees south-southeast of eclipsing binary star system Ruchbah (δ Cas - mag. +2.7). This star is one component of the characteristic "W" asterism of Cassiopeia. The brightest star inside NGC 457 is Phi Cas (φ Cas - mag. +5.0). Despite not being a member of the cluster, this foreground star is visible to the naked eye. Together with another non-cluster star - seventh magnitude HD 7902 (HIP 6229) - they form the bright eyes of the Owl greatly adding to the splendour of the view through backyard scopes.
NGC 457 is best seen from Northern Hemisphere latitudes during August, September and October. It appears high in the sky and even overhead from many locations. From latitudes greater than 32N, the Owl is circumpolar and never sets.
The Geminids or "Winter Fireworks" is widely regarded as the richest and most active of the annual meteor showers with this year spectacle peaking on night of December 13th/14th. During peak activity up to 120 meteors per hour - many of them bright - can be seen under perfect conditions. Of the other annual showers only the August Perseids come close to attaining such highs.
In 2013, the glare from a waxing gibbous Moon significantly interfered with the Geminids around peak time, but this year's prospects are more favourable; the last quarter Moon doesn't rise until after midnight on peak day. By keeping the Moon out of view the most intense period of the shower can be observed with little interference.
Comet Lovejoy (C2014/Q2), the fifth comet to be discovered by Australian amateur astronomer Terry Lovejoy on August 17, 2014, has now brightened sufficiently to move with binocular range. As it continues to increase in brightness, it should soon be visible to the naked eye and is expected to peak at about magnitude +4.5 during the middle of January.
Since the comet is located quite far south of the celestial equator it's well placed for observation from southern and tropical latitudes during December. For those located at northern temperate latitudes it's not visible until the second half of the month but after that it's observable in excellent condition.
The Hyades is a very large loose naked eye open cluster located in the constellation of Taurus. It spans 5.5 degrees of sky, which is equivalent to 11 times the diameter of the full Moon. At a distance of 153 light-years this is the nearest open cluster - the Ursa Major Moving Group is closer, but's extremely scattered and more of a cluster like object than a true cluster. Consequently, the Hyades is one of the top studied open clusters of all.
The Hyades is easily found as it circles the brightest star in Taurus, first magnitude orange giant star Aldebaran (α Tau - mag. +0.87). It's not unreasonable to assume that Aldebaran is also a member of the Hyades. However, it's purely a foreground star, an interloper located only 65 light-years distant that happens to be in the same line of sight. As a naked-eye object, the Hyades have been known since prehistoric times.
The cluster is best seen from northern latitudes during the months of November, December and January.
Mercury remains unsuitably placed for observation for most of December. The planet is currently on the far side of the Sun, passing through superior conjunction on December 8th and staying out of view until the very end of the month. It then re-appears as a difficult early evening object low down above the west-southwest horizon from tropical and southern latitude locations.
For example, on December 31st from latitude 35S (approx. equal to Sydney, Cape Town and Santiago), Mercury shines at mag. -0.8 appearing only 4 degrees above the west-southwest horizon 30 minutes after sunset. Positioned a couple of degrees above Mercury is much more brilliant Venus. From Northern Hemisphere latitudes, the planet is too low down to be seen this month.
Mercury reaches aphelion on December 8th when it's located 0.467 AU (approx. 69.9 million kilometres or 43.4 million miles) from the Sun.
Venus is also an early evening object for observers in the tropics and Southern Hemisphere. It's visibility improves as the month progresses although the planet remains low down above the west-southwestern horizon. However, at magnitude -3.9 it's unmistakable due to its brilliance.
The first item in the Caldwell catalogue is NGC 188 an open cluster located in the far northern constellation of Cepheus. It was discovered by John Herschel - the son of William Hershel - on November 3, 1831. He originally recorded it as h 34 in his 1833 catalogue and then included it as GC 92 in his subsequent General Catalogue of 1864. The cluster finally became NGC 188 in John L.E. Dreyer's New General Catalogue of 1888.
NGC 188 is the northernmost open cluster in the sky, it's positioned only 4.75 degrees from the North Celestial Pole. Located at such a northerly declination means the cluster is circumpolar from almost the entire northern hemisphere. It can be seen from the Southern Hemisphere but only from latitudes north of 5 degrees south. Even then it never climbs more than a few degrees above the northern horizon.
The Chained Woman
Andromeda is located in the northern part of the sky away from the plane of the Milky Way. It was one of the original 48 constellations plotted by second century astronomer Ptolemy and today remains as one of the modern 88 constellations defined by the IAU (International Astronomical Union). Andromeda is named after the princess in Greek Mythology, who was the daughter of King Cepheus and Queen Cassiopeia. Legend has it, she was chained to a rock on the coast to be sacrificed, in order to save the land from the large sea monster Cetus. Returning Perseus came across the shackled princess and lay in waiting for the monster, before killing it and then marrying the princess.
For amateurs, Andromeda contains one famous galaxy, many faint galaxies, a selection of nice double stars, a couple of bright open clusters, a few variable stars and a beautiful planetary nebula. The deep sky object that dominates the constellation is the spectacular Andromeda galaxy (M31), which is the largest member of our Local Group. At 2.54 Million light-years, it's the most distant object in the night sky that's easily visible with the naked eye.
Andromeda is best seen from Northern Hemisphere latitudes during the months of October, November and December.
The Leonids is a famous meteor shower that's peaks this year on November 17th. Although 2014 hasn't been a particular good year for meteor showers, this shower promises to be a good one as the Moon won't significantly interfere. For the Leonids, just over a dozen meteors per hour can normally be seen under ideal conditions. However in the past it has produced some of the most spectacular meteor storms ever seen; one particular outburst in 1833 being of incredible proportions.
The comet that is the source of the Leonids is 55P/Tempel-Tuttle or more commonly known just as Temple-Tuttle. It is a periodic comet discovered by Ernst Tempel on December 19, 1865 and independently by Horace Parnell Tuttle on January 6, 1866. With an orbital period of only 33 years, it can pass close to the Earth and on such occasions, the chances of a witnessing a super meteor storm are high indeed.
The Northern part of the Taurid meteor shower peaks this year on the night of November 11/12th. Although the Zenith hourly rate (ZHR) or the number of meteors that can be seen per hour under ideal conditions is low, the Northern Taurids often produces fireballs that are a spectacular sight as they pass by. However, this year's event will be affected by the 75% lit waning gibbous Moon - located in neighbouring Gemini - which will wash out all but the brightest meteors.
Parent Comet and Radiant
The Taurids have long been identified as an old meteor stream, with the first recorded observations made as far back as 1869. Although frequently seen during the remainder of the 19th century, it was not until 1918 that it was realised that a new meteor shower had been found. The Taurids are a little unusual in that they now have two separate shower radians caused by the gravitational effect of the planets, especially Jupiter. Although originating from the same parent comet, overtime they spread out to form two individual meteor showers, now known as the Northern Taurids (NTA) and the Southern Taurids (STA). Both Taurids have low Zenith hourly rates (ZHR), with the Southern Taurids peaking a week before the Northern Taurids. The Southern Taurids peaked last week but visible meteor numbers were significantly impacted by the full Moon.
Mercury reaches greatest elongation west on November 1st. On this day the planet is located 19 degrees from the Sun and consequently well placed as an early morning object for observers at northern temperate and tropics latitudes. This also happens to be the most favourable morning apparition of the year from the Northern Hemisphere.
For example, from latitude 52N (e.g. London, England) Mercury will start the month 11 degrees above the east-southeast horizon at 40 minutes before sunrise. Shining at magnitude -0.6 it will be possible to spot the planet for a short time as it rises before it's finally lost to the bright twilight glare. The planet appears slightly lower down each subsequent morning - although at the same time marginally increasing in brightness - until about the third week of the month when it will be no longer visible.
From the southern hemisphere, the angle of the ecliptic is unfavourable and therefore Mercury is unsuitably placed for observation this month.
The annual Orionids meteor shower peaks this year on October 21st and the prospects are excellent as the Moon will not interfere. Generally regarded as a strong shower, the Orionids or Orionid meteor shower is active between October 2nd and November 7th, although most activity is at peak date or a few days before or after it. In the past, rates of up to 70 per hour have been observed but normally the shower is not so active; a figure between 20 and 25 is more the normal at the moment.
The Orionids parent comet is the most famous of all, Halley's Comet (1P/Halley). There are two annual meteor showers associated with Halley's Comet, the Eta Aquariids shower that occurs in May and the then the Orionids. Of the two the Orionids is far the more prolific.
Although Halley is now in the outer solar system and will not return close to Earth until 2061, it's worth remembering that Orionids meteors stem from particles leftover from Halley's Comet apparitions every 76 years. Every observed Orionid is actually a small part of the famous comet streaking through and subsequently burning up in the Earth's atmosphere.
Comet PanSTARRS (C/2012 K1) has now passed perihelion and is once again visible in the morning sky. The comet made its closest approach to the Sun on August 27, 2014. On this date it passed approx. 1.05 AU (157 million kilometres or 98 million miles) from the Sun; a similar distance to that of the Earth/Sun.
PanSTARRS was discovered using the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) telescope located near the summit of volcano Haleakala on the Hawaiian island of Maui. At discovery, the comet was very dim (mag. +19.7) and located 8.7 AU (1.3 billion kilometres or 800 million miles) distant, far beyond the orbit of Jupiter and almost as distant as Saturn.
Ice giant planet Uranus comes to opposition on October 7th. The distant outer planet shines at magnitude +5.7 amongst the stars of Pisces and therefore bright enough - but only just - to be spotted with the naked eye from a dark site. However, this year it will be impossible to spot Uranus with the naked eye at opposition since the nearby full Moon interferes.
At the beginning of October observers at southern latitudes should be able to catch Mercury low down towards the western horizon just after sunset. However, it won't be long before the planet is lost to the bright twilight glare as it draws in towards the Sun. Mercury then passes through inferior conjunction on October 16th. The planet is such a fast mover that observers at equatorial and northern temperate latitudes will be able to spot this elusive world low down towards the east just before sunrise during the last week of October. From southern temperate latitudes, Mercury is unsuitably placed for observation during this time.
The planet increases in brightness from mag. +0.8 on October 25th to -0.5 at the end of the month.
Venus is currently located on the opposite side of the Sun and passes through superior conjunction on October 25th. As a result the planet is not suitably placed for observation during October.
Mars remains an evening object during October but the "Red planet" has now faded to mag. +0.9, down from a peak of -1.5 during opposition last April. On September 27th, the planet passed 3 degrees north of its "rival", red supergiant Antares (α Sco - mag. +1.0) the brightest star in Scorpius. At magnitude +0.8, Mars was fractionally the brighter but otherwise to the naked eye they appeared similar. The planet is now "speeding" away from Antares as it continues its direct motion through Ophiuchus before moving into Sagittarius on October 21st.
M87 is a supergiant elliptical galaxy that's a prominent member of the Virgo cluster of galaxies. It's one of the largest and most luminous galaxies known and a strong source of radiation, particularly radio and X-ray emissions. At the centre of M87 is a supermassive black hole with a jet of extremely energetic plasma extending outwards for at least 5000 light-years. The galaxy is therefore an interesting object for both professional and amateur astronomers alike.
With an apparent magnitude of +8.6, M87 is the second brightest of the Virgo cluster galaxies; only M49 at mag. +8.4 is brighter. On dark moonless nights it's visible with 7x50 or 10x50 binoculars, appearing as a faint hazy patch of light. The galaxy was one of eight discovered by Charles Messier on March 18, 1781. On this day he also re-discovered fine globular cluster M92.
M87 lies at the heart of the Virgo cluster. It can be found by imagining a line connecting Denebola (β Leo - mag. +2.1) with Vindemiatrix (ε Vir - mag. +2.8). Just over half way along this line is M87. Faint elliptical galaxy M89 is positioned just over a degree east of M87 with galaxy pair M84/M86 located 1.5 degrees northwest of M87.
The Virgo galaxies are best seen during the months of March, April and May.
M88, mag. +9.6, is a fine spiral galaxy located in Coma Berenices that's a member of the Virgo cluster of galaxies. It has a reasonably high surface brightness - partly due to its favourable inclination of 30 degrees - and therefore a nice small telescope object. It appears somewhat like a much smaller and fainter version of M31, the spectacular Andromeda Galaxy.
M88 is one of the brightest Seyfert galaxies in the sky. These types of galaxies exhibit extremely active quasar like nuclei and are strong emitters of electromagnetic radiation with highly ionised spectral emission lines present. They are named after 20th century American astronomer Carl Seyfert who first identified them. Galaxies M51, M66, M77, M81, M87 and M106 also belong to this class of object.
M88 was one of the eight Virgo cluster galaxies discovered by Messier on his most productive night, March 18, 1781. Messier's description of M88 was of a "nebula without star between two small stars and one star of the sixth magnitude, which appear at the same time as the nebula in the field of the telescope". He also remarked that it was similar in appearance to M58. William Parsons the 3rd Earl of Rosse was the first to recognise the spiral shape and listed M88 as one of 14 "spiral nebulae" discovered to 1850.
As with some of the Virgo galaxies, locating M88 can be challenging since there are no bright stars located in the vicinity. The galaxy is positioned about a degree north of the Coma Berenices-Virgo constellation boundary with the general area of sky located midway between stars Denebola (β Leo - mag. +2.1) and Vindemiatrix (ε Vir - mag. +2.8). Tenth magnitude barred spiral galaxy M91 is located just east of M88.
M89 is another member of the Virgo Cluster of galaxies. It's a small magnitude +10.0 elliptical galaxy (type - E0) discovered by Charles Messier on March 18, 1781. On this bumper night for Messier he also discovered seven other Virgo galaxies and re-discovered globular cluster M92 in Hercules. Recent observations indicate that M89 may be nearly perfectly spherical in shape. This is unusual because all other known ellipticals are elongated. However, it's possible that the spherical nature of M89 is purely a visual affect resulting from its orientation from our perspective.
The galaxy is not as bright as some other group members and therefore a challenging small telescope object. Messier's original discovery observation acknowledges this: "extremely faint and pale and it's not without difficulty that one can distinguish it". The galaxy is best seen with large telescopes but generally featureless and rather unexciting through most amateur instruments.
M89 is located in Virgo just south of the Virgo-Coma Berenices constellation boundary. It's positioned roughly 60% along an imaginary line connecting stars, Denebola (β Leo - mag. +2.1) and Vindemiatrix (ε Vir - mag. +2.8). Slightly brighter spiral galaxy M90 is 0.75 degrees northeast of M89. One degree southeast of M89 is fine barred spiral galaxy M58 with supergiant elliptical galaxy M87 located about a degree west of M89.
The Virgo galaxies are best seen during the months of March, April and May.
M100, mag. +9.5, is a spiral galaxy located in the southern part of constellation of Coma Berenices. It's one of the brightest members of the Virgo cluster of galaxies appearing almost face-on from our perspective. M100 exhibits prominent well-defined spiral arms and is therefore regarded as an example of a grand design spiral galaxy; other notable galaxies that fall into this category are M51, M74, M81 and M101.
M100 was discovered - along with M98 and M99 - by Pierre Méchain on March 15, 1781. Charles Messier subsequently observed all three objects and added them to his catalogue on April 13, 1781. He described the galaxy as faint without stars. It was not until 1850 that the spiral nature of M100 was first detected. Ango-Irish astronomer William Parsons the 3rd Earl of Rosse was the person to achieve this. He included M100 in a list of 14 spiral nebulae he had observed.
Finding the area of sky where M100 is positioned is not so difficult once one is familiar with the location of Virgo cluster. The centre of the cluster is located close to supergiant elliptical galaxy M87 about halfway along a line connecting Denebola (β Leo - mag. +2.1) with Vindemiatrix (ε Vir - mag. +2.8). M100 is positioned towards the northern section of the group, 2 degrees southeast of star 11 Com (mag. +4.7).
The Virgo cluster galaxies are best seen during the months of March, April and May.
Comet Jacques is now past its best but remains well placed for observation high in the sky during the second half of September. In July when at its brightest, Jacques reached the cusp of naked eye visibility; just too faint to be seen without optical aid but nevertheless a superb sight in binoculars, telescopes and a wonderful object for astro imagers.
M90 is a spiral galaxy located in Virgo. It's a member of the Virgo Cluster and one of the largest and brightest spirals in the group. With an apparent magnitude of +9.6, it's visible through small scopes as a reasonably bright oval shaped patch of light. M90 appears bright in medium size telescopes but to spot the spiral structure requires a larger amateur scope.
The galaxy was one of eight galaxies, all Virgo members, discovered by Charles Messier on March 18, 1781. It's located about 60 Million light-years distant and is intrinsically large with an actual diameter of 165,000 light-years, more than the Andromeda Galaxy (M31). It's estimated to contain a trillion stars.
M90 is positioned close to the centre of the Virgo cluster and right at the Virgo-Coma Berenices constellation boundary. The centre of the cluster is located roughly halfway along a line connecting stars, Denebola (β Leo - mag. +2.1) and Vindemiatrix (ε Vir - mag. +2.8). In the same area of sky are M84, M86 and M87 with M90 positioned 1.5 degrees northeast of M87. The small elliptical galaxy M89 is 0.75 degrees southwest of M90 with M91 about a degree to the north-northwest of M90. Tenth magnitude spiral galaxy M88 is located 1.5 degrees northwest of M90.
The Virgo galaxies are best seen during the months of March, April and May.
Comet Oukaimeden, which was discovered at the end of last year, has recently brightened sufficiently to move within binocular and small telescope range. During September, the comet should continue to improve until peaking at about magnitude +6.0 on the 19th, just short of naked eye visibility. It can be seen from the tropics and southern locations.
At the beginning of the month, Oukaimeden appeared as a well-placed morning object high in the sky towards the east before sunrise from the tropics and Southern Hemisphere. As the month progresses, it draws in towards the Sun but still remains well placed for at least the first two weeks of the month before switching to the evening sky. It should then be visible low down above the western horizon just after sunset during the last week of September.
From mid-latitude northern latitudes, Oukaimeden is not suitably placed for observation. It was visible for the first few days of September, low down towards the eastern sky during morning twilight, but then quickly lost to the Sun's glare.
Oukaimeden was discovered on November 12, 2013 at Oukaimeden observatory in Marrakech, Morocco using a 0.5-metre (20-inch) reflecting telescope by Michel Ory. It was the fourth comet discovered at the observatory and the first by Michel Ory. At apparent magnitude +19.4, Oukaimeden was extremely faint when found.
M104 more commonly known as the Sombrero Galaxy is a spectacular, almost edge-on, spiral galaxy located in Virgo. At magnitude +8.4, the Sombrero appears in binoculars as a small patch of nebulosity. Its most striking feature - visible in medium/large sized amateur scopes - is a ring of thick dust that encapsulates the bulge of the galaxy, giving the appearance of a Sombrero hat. Many astronomers regard M104 as the finest of all galaxies in Virgo.
Pierre Méchain discovered M104 on May 11, 1781. A couple of years later he described the galaxy in a letter to Johann Bernoulli and subsequently it was published in the Berliner Astronomisches Jahrbuch (Berlin Astronomy Year Book). Charles Messier made hand-written notes about this and five other objects but none were included in the final published catalogue version. The Sombrero Galaxy was finally added to the "official" catalogue in 1921 with the other five "missing" items (M105 to M109) added a few years later.
M104 was one of the first galaxies to have its spectra and velocity measured by Vesto Slipher in 1912. He noted that the object was redshifted and therefore receding from us, the current accepted rate being 900 km/s. Slipher's redshift calculation of M104 along with similar observations from other galaxies pointed towards an expanding Universe, hence providing a key piece of evidence for the Big Bang Theory.
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