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Image created with SkySafari for Mac OS X, ©2010-2012 by Southern Stars, www.southernstars.com.


November 2017 Sky Guide

  

The Solar System


The Moon

 

The Moon begins November at Waxing Gibbous phase, around 92% illuminated, in the non-zodiacal constellation of Cetus, the Whale. It reaches Full on November 4th on the Cetus/Aries border, rising just before a quarter to five in the evening (from latitude 51 degrees N), and setting a little after a quarter to seven the following morning. This means inevitably, the first few days of November are not so great for deep sky observations or imaging with anything less than very narrowband filtration. 

 

The Moon reaches Last Quarter on the 10th, when fairly high in the sky (from a Northern Hemisphere perspective) in Leo. Though now beyond the point in the year of presenting the highest High Autumnal Morning Crescent phases to those in the temperate Northern Hemisphere - this is still a great time to observe the Moon's western limb, if you're an early riser. 

 

On the morning of the 15th, before dawn, the thin old crescent Moon, some 10% illuminated, can be found just 3 1/3 degrees to the east of Mars in the SE, just before dawn.  You may be able to find the Moon on the morning of the 17th, forming a triangle with Jupiter and Venus, low in the SE, before the Sun rises. 

 

The Moon and surrounding planets, predawn, November 15th. Image created with SkySafari for Mac OS X, ©2010-2012 by Southern Stars, www.southernstars.com.


The Moon becomes New, the following day, November 19th, when it joins the Sun in the eastern half of Virgo. After this point in the month, the Moon becomes an evening object, joining Mercury and Saturn low in the sky on the evening of the 20th, just after sunset. 

 

The Moon continues its journey through the southerly parts of the ecliptic, passing through Libra, Ophiuchus, Scorpius, Sagittarius and Capricornus until reaching First Quarter in Aquarius on the 26th. 

 

The Moon ends the month on the Cetus/Pisces borders, at 84% illuminated Waxing Gibbous phase.

 

 

The Planets

 

Mercury 

 

The Innermost planet begins the month as a relatively bright -0.4 mag evening target in Libra. Although fairly well separated from the Sun (by just over 14 degrees), Mercury is very low in the sky to sunset, so it's going to be a difficult spot in the dusk, sitting just over 2 degrees high as the sun goes down (from 51 degrees N).

 

Mercury is heading towards maximum eastern elongation from the Sun, which it reaches on November 24th. However, due to the Sun and Mercury being in the south of the ecliptic, even during the latter part of the month, Mercury will be really low on the western horizon for those of us observers in the temperate northern hemisphere - reaching under 4 degrees in altitude at sunset on the 15th from 51 degrees N, although those further south in the equatorial regions of the Earth and the Southern Hemisphere will see it much better placed. By the time maximum eastern elongation is reached this figure has climbed to just over 5 degrees elevation (again from 51 degrees N). . 

 

Mercury ends November at mag -0.0 in Sagittarius, sitting just below Saturn as the Sun goes down. 

 

 Mercury and Saturn, Sunset, 30th November. Image created with SkySafari for Mac OS X, ©2010-2012 by Southern Stars, www.southernstars.com.


Venus

 

Venus, at -3.9 on the 1st, is still an easy object to catch in the morning sky. At 96% illumination, our neighbouring planet sits just over 13 degrees high at sunrise (from 51 degrees N), making it low, but still fairly straightforward to observe from the temperate northern hemisphere. Venus and the Sun are separated by about 17 degrees on the 1st. 

 

On the morning of the 13th, Venus comes into very close conjunction with Jupiter, separated by around 1/4 of a degree - easily putting both objects in the field of view of a telescope with a wide field, medium power eyepiece and making binoculars observation of the event very simple. Jupiter, at mag -1.7 and 30.8 arc seconds across will be less brilliant, though larger in angular size than Venus. Having the third and fourth brightest objects in the sky in such close proximity should not be missed. 

 

Venus and Jupiter in conjunction, 13th November - synthesised telescopic view.  Image created with SkySafari for Mac OS X, ©2010-2012 by Southern Stars, www.southernstars.com.

By mid-month, Venus has dipped a little in altitude at sunrise (just over 10 degrees high from 51 degrees N), but hasn't in brightness, remaining much the same as it was at the beginning of the month. 

 

However, the trend as far as Venus is concerned continues to be downward, as the planet slips towards the Sun. By the time November is at its end, Venus hasn't changed in brightness, but now stands around 6 degrees high at daybreak (again, from 51 degrees N).  By this point in time, Venus and the Sun are separated by just under 10 degrees. 

 

 

Mars

 

Mars starts November as a morning target in Leo. At +1.8 mag and just 3.9 arc seconds diameter, it is not a particularly inspiring object to observe at the present time. Mars' proximity to the Sun, just under 33 degrees on the 1st, doesn't make it especially hard to find, especially with the brighter Venus, to the SE nearby, but once located, the planet's small disk and comparatively low magnitude make for a rather disappointing experience at the telescope. 

 

Mars is signposted by the brighter Venus, Dawn, 1st Novemebr.  Image created with SkySafari for Mac OS X, ©2010-2012 by Southern Stars, www.southernstars.com.

We on Earth are slowly catching up with Mars on our faster interior orbit, but this is a rather drawn-out process. Opposition with Mars - our next closest approach to the planet - won't be until the end of July 2018. We still have some way to go before the Red Planet starts being a truly rewarding experience to observe. 

 

By the middle of the month, nothing has changed much as far as Mars is concerned. The planet's brightness has increased to +1.7 mag and it's angular diameter is now 4.1 arc seconds across. 

 

By November's end, Mars stands just over 28 degrees high at sunrise (from 51 degrees N), still at +1.7 mag and now presents a 4.2 arc second diameter disk.

 

 

Jupiter 

 

Jupiter is re-emerging from superior conjunction into the morning sky, so won't be easily observable until the latter part of the first week of November. 

 

As previously mentioned, Jupiter and Venus come together in very close conjunction on the morning of the 13th, which should be spectacular to observe in any instrument. 

 

By mid-month, Jupiter stands 11 1/2 degrees high at sunrise (from 51 degrees N), still shining at -1.7 mag. 

 

By November's end, Jupiter's brightness hasn't changed, but the planet now stands just over 18 degrees high as the Sun rises  (again, from 51 degrees N), a resident of Libra. 

 

 

Saturn

 

The Ringed Planet is an evening object during November. Though low in the south of the sky from a northern hemisphere perspective, Saturn always presents a pleasing view in a telescope, though those in the Southern Hemisphere will see it undeniably better. 

 

Saturn at sunset, 1st November.  Image created with SkySafari for Mac OS X, ©2010-2012 by Southern Stars, www.southernstars.com.

At +0.5 mag and 15.5 arc seconds across on the 1st, Saturn is hardly striking from a naked eye perspective, but is still brighter than any star in the same area of sky - in this case the Ophiuchus/Sagittarius area. It sets around 2 1/2 hours after the Sun (from 51 degrees N). 

 

By mid-month, Saturn is still much the same size and brightness and now sets a little shy of two hours after the Sun (again from 51 degrees N). 

 

At the end of November, Saturn is still +0.5 mag and now sets around 1 1/4 hours after the Sun. By this point in time, observations of Saturn start to become fleeting as we head towards superior conjunction in December. 

 

 

Uranus and Neptune 

 

During November, both Uranus and Neptune are favourably positioned for evening observations in Pisces and Aquarius respectively. 

 

The Waxing Gibbous Moon appears between Uranus and Neptune, early evening, November 1st. Image created with SkySafari for Mac OS X, ©2010-2012 by Southern Stars, www.southernstars.com.


Uranus is, as ever, the brighter and easier of the two at +5.7 mag and 3.7 arc seconds across. Lying in the central "V" of the stars of Pisces, the planet isn't especially hard to find from a reasonable location. The Moon provides a handy guide to Uranus' position on the evening of the 2nd, when both objects transit together at almost the same time from a European and African observational perspective. The Moon will sit around 5 1/4 degrees to the south of Uranus as this occurs. 

 

On the evening of the 26th and 27th November, the Moon can also be used as a useful signpost to the location of Neptune. On the 26th, the Moon sits to the west of Neptune by 6 3/4 degrees. The next night, the separation occurs with the Moon to the east of Neptune, by about the same amount. 

 

With Neptune at +7.9 mag and 2.3 arc seconds in diameter, it is a great deal fainter than Uranus and will need a reasonable pair of binoculars in order to make a positive identification. Higher power telescopic views will show the planet as a noticeably blue colour disk, resembling a planetary nebula. Although a challenge to find without the use of a telescope with a goto mount, and accurate star charts, once found, Neptune is unmistakable. You will then be looking at the furthest true "planet" (now Pluto has been demoted) in our solar system. While there is some evidence to suggest that there may be a reasonably large planet lurking out beyond the range of Pluto, Eris, Sedna and the dwarf planets of the outer solar system, the fact this has evaded detection so far (if it exists), by even the largest telescopes at humanity's disposal, means Neptune is, as far as we're concerned, the boundary of the planetary solar system. If there is a large planet further out, you certainly won't be able to see it with binoculars - so why not give Neptune a go?

 

 

Comets

 

Comet C/2017 O1 (ASASSN) is well placed for observation during November, travelling north through the stars of the faint constellation Camelopardalis (the Giraffe) during the first half of the month.  The comet may have approached the limits of naked eye visibility (from a very good location), during lithe latter part of October - but as most readers know, cometary prediction is a difficult art. It seems as if C/2017 O1 was found undergoing an outburst, which may have boosted its initial brightness somewhat. However, most recent observations (at time of writing), but the comet towards the upper range of brightness estimates. At worst, C/2017 O1 should still be a binocular object and worth looking out for. 

 

After the 15th, the comet crosses the border in to northern Cepheus and sits a few degrees from Polaris as November ends. 

 

 

Meteors

 

There are two notable meteor showers in November: the Southern Taurids and the better-known Leonids. While both showers will peak with zeniths hourly rates of 10-20 meteors, the Southern Taurids will be heavily affected by Moonlight, peaking as they do around November 5th, with the Waning Gibbous Moon just past Full in neighbouring Gemini. 

 

The Leonids are a much better prospect, with their peak falling over the 17-18th November, which coincides neatly with the New Moon. 

 

The Leonids are famous for their outbursts, which usually peak every 33 years, after the return of their parent comet, 55/P Tempel Tuttle, which replenishes the orbital debris field which feeds the shower. This can lead to peaks of thousands of meteors per hour at best. However, this year, we are in somewhat of a trough when it comes to the Leonids, as we can expect 10-20 observable meteors per hour.  As we are pretty much in the middle of the 33 year cycle of activity, maybe this is only to be expected, though the shower has peaked with near-Perseid/Geminid levels of activity as recently as 2009 and 2012. These peaks were due to the Earth encountering steams of material laid down in much older passes of Tempel Tuttle. Indeed, the most amazing storm recorded - that of 1833, which resulted in ZHR of an astonishing estimated 250,000 meteors - was caused not by that year's cometary return, but the previous 1800 debris field. 

As previously mentioned, this year's Leonids won't hit the heights of their best showings, but with the Moon out of the way, if the weather is kind where you are, observing conditions should be ideal. 

 

Leonid Radiant - November 17-18th 2016.  Image created with SkySafari for Mac OS X, ©2010-2012 by Southern Stars, www.southernstars.com.


 

 

Deep Sky Delights in Perseus, Andromeda & Triangulum 


Perseus, Andromeda and Triangulum.  Image created with SkySafari for Mac OS X, ©2010-2012 by Southern Stars, www.southernstars.com.

We start this month in the southerly part of Perseus, where the open cluster M34 is located. M34 is an original part of Messier’s List and was first identifed by Giovanni Battisa Hodierna in the mid-1600s. Hordierna was born in what is now Dubrovnik in Croatia, though did most of his observing from the court of the Duke of Montechiaro in Sicily. Hodierna was a leading telescopic observer of his day and complied a pre-Messier catalogue of Deep Sky objects. M34 was part of this original list, though Messier discovered it independently in 1764. The cluster is easily spotted in smaller binoculars and occupies an area of sky roughly equivalent to the diameter of the Full Moon. At +5.19, M34 is reasonably bright and contains around 80-100 observable stars in medium-sized telescopes (the actual number stands at around 400, but many these are beyond the range of amateur instruments). Precise professional observations of M34’s movement have concluded that there is a distinct possibility that M34, the neighbouring Pleiades and a number of other nearby clusters are exhibiting a common angular motion, suggesting a common origin. M34 lies 1400-1500 light years away. 

M34. Image Credit: Ole Nielsen - Creative Commons.

East of M34 is a more challenging object, the Perseus A Galaxy, or NGC1275. At +11.89 mag, this is not an intrinsically bright galaxy, though it is quite a compact target and can be seen in medium to larger telescopes. This object is actually a pair of galaxies that have undergone a collision and have formed a larger galaxy strewn with laments of stars and dark material, most likely blasted outwards by the supermassive Black Hole at the heart of the system. Perseus A is a Seyfert Galaxy - strongly emitting on Radio frequencies, suggesting a large amount of star formation. NGC1275, at 235 million light years distance, is one of the most prominent members of the Perseus cluster of galaxies, which occupies this region and is amongst the largest structures in the known Universe. 

5 degrees to the west of M34 lies the most famous eclipsing binary star in the sky, Algol, or Beta Persei.  Algol represents the eye of the head of the Gorgon Medusa, whose gaze would turn to stone all those unfortunate enough to look at it. According tho the legend, Perseus held Medusa’s severed head up to the sea monster Cetus in the successful rescue of Andromeda. Cetus was turned to stone and Perseus unchained Andromeda from the rock to which she was attached. Algol’s name derives from the Arabic “ra’s al-ghul”, translated as “head of the ghoul” - though it has been know by several equally unfortunate titles.  In Hebrew, Algol was known as “Rosh ha Satan” or “Satan’s Head”. A 16th century text labels Algol as “Caput Larvae” or “Spectre’s Head”. But the prize used to go to the now sadly disproved ancient Chinese description, “Tseih She” or “Jishi”, meaning “Piled Up Corpses” - though this is now thought to refer to Pi Persei instead. Regardless, Algol was part of the Anciet Chinese constellation of the Tomb or Mausoleum. No matterwhich culture attempts to define Algol, it always seems to have a sinister undercurrent - quite unfair really, as it is a fascinating object. 

Algol’s eclipsing binaries occupy a startlingly small amount of space - just 0.062 Astronomical units, or around 5.76 million miles, separates the two stars. These two stars are Beta Persei A and Beta Persei B (there is a third member of this system, Beta Persei C which plays no part in the eclipse). Beta Persei A is the brightest of these stars and is eclipsed by the dimmer Beta Persei B every 2 days, 20 hours and 49 minutes, for around 10 hours at a time. This eclipse has the effect of dimming the +2.1 mag star to +3.4 mag for the period of the eclipse. There is also a much shallower dimming when A eclipses B, though this is very difficult to detect visually. The main eclipse can easily be detected with the naked eye and is possibly the reason that this star was held in such suspicion by ancient astronomers. Regardless, it is a very clear example of stellar orbital dynamics and Algol, suspicious or not, continues to be of interest as a result. It’s always worth comparing the brightness of Algol with Almach - as they’re normally roughly similar brightness. If this isn’t the case, you can be sure the Algol’s in eclipse. 

Nine and a half degrees east of Algol sits the 2.91 mag star Adid Australis, Epsilon Persei, which is a useful is a pointer to those attempting to locate NGC1499 - the California Nebula - which lies along the line between this star and the neighbouring +4.40 mag star Xi Persei, or Menkib. a prime candidate for Supernova (though lying at a distinctly safe distance of 1200 light years). The California Nebula can be found just under a degree to the North of Menkib. 

The California Nebula by Telescope House's Mark Blundell

Discovered in 1884 by Barnard (he of Barnard Star’s fame), the California is a confusing object Technically it is a bright +5 mag object of very large proportions - 145 x 40 arc minutes (just slightly smaller than M31, the Andromeda Galaxy), but due to its size, it has low surface brightness. The California is very easily picked up by cameras with relatively modest exposures, but to see it visually requires two things: a decent sky and a Hydrogen Beta Filter. Many observers consider aperture to be of importance when picking out low surface brightness objects from the background sky, and while this is normally very sound advice, with large objects such as the California, this must be tempered by the amount of sky a telescope can adequately display at low power. It has been suggested than NGC1499 can be seen in some cases better with smaller telescopes, of shorter focal lengths at low power with a Hydrogen Beta Filter. Larger instruments will show the curtain of light of the edge of the nebula well under filtration and can pick out more lament detail within its inner structure, but a smaller wide eld telescope can potentially t the entire nebula into a single eld of view - a potentially superior view from an aesthetic standpoint. Others have observed the nebula with the naked eye from a dark site, simply by holding an H Beta Filter up to its area of sky. The H-Beta filter, unlike the more popular UHC and OIII options is only of great use for this nebula, and the adjacent nebulas the Horsehead in Orion and the North American in Cygnus and a few lesser objects. For those attempting to see these famous objects, it really is a must. 

It is thought that the radiation from nearby Xi Persei is responsible for exciting the gas of the California and causing it to glow. The rich gas and material deposits in this area of the Milky Way have given birth to many massive stars, of which the previously mentioned Menkib and Adid Australis are probably prime examples. The California Nebula is thought to lie some 1000 light years from our position in the galaxy and is about 100 light years across at its widest point. 

Moving to the opposite end of Perseus from the California Nebula, we come to the spectacular Double Cluster, or Sword Handle - NGCs 869 and 884. It is perhaps testament to the easy nature of their observation that they were never given Messier number classification. These twin clusters - and there can be little doubt about their mutual origin - are of +5.9 visual magnitude and are excellently seen through binoculars of all sizes, but really come alive in wide field telescopes. Of the two, NGC 869 is the slightly more populous being of 3700 solar masses to NGC 884’s 2800 and are thought to between 3.2 and 12.8 million years old (sources, again differ on this figure) - considerably younger even than the Pleiades’ 75 million years. Both clusters have in excess of 150 hot blue stars visible to amateur telescopes and are also a fabulous target for astrophotography. Both elements of the Double Cluster lie between 7500-9600 light years distance from us and are approaching us at around 39 km per second. 

The Double Cluster. Image Credit: ESO, S Bruner - Creative Commons

The last target we shall examine in Perseus is M76, otherwise known as the “Little Dumbell”, due to its physical similarity to M27 the Dumbell Nebula in Vulpecula. Found 3 degrees North of 51 Andromedae, the other of Andromeda’s feet (alongside Almach), M76 is a very compact object and one of the dimmest of the Messier list at +10.10 mag. Still, as with many planetary nebulae, it is an attractive object. Unlike the Ring Nebula, M57, M76 is presented side on, so we can clearly see the two lobes of bass that were ejected from the central star. Were this object presented to us end on, much like the Ring Nebula, we would see the distinctive disk or ring-like pattern, rather than a sort of hourglass shape that M76 resembles. As with most planetaries, M76 responds well to OIII filters. 

M76 by Telescope House's Mark Blundell

M76’s distance is widely disputed, some sources give it as 1500 light years distances, others in excess of 15,000 light years away. Spectroscopy has shown it is certainly approaching the Solar System, at a rate of 19 km per second. 

Moving away from M76, we cross the border into Andromeda and turn our attention to the less well-known, but prominent and easily-found galaxy in the constellation: the wonderful NGC891. 11 1/2 degrees to the SE of M76 and discovered by Sir William Herschel in 1784, NGC891 is a spiral galaxy, potentially much like our own, presented absolutely edge-on to our perspective. At +9.89 mag, it is not especially bright, but 

it is well-condensed. Its axis is bisected by a dark dust lane, splitting the object in two. In telescopes of moderate aperture, NGC891 appears like a shard - or rather two parallel shards of light, with a very small bulge of the galaxy’s core in the centre. It is a lovely object - maybe not having the glamour of its neighbour M31 (NGC891 is 30 million light years away from us), but a very rewarding galaxy to observe or photograph. 

NGC891 by Telescope House's Mark Blundell

3-degrees to the west of NGC891 can be found Gamma Andromedae, or Almach - an easy pointer to the galaxy, but an equally interesting object in its own right. Almach is one of the sky’s best double stars: a pair of orange-yellow and striking greeny-blue stars of +2.17 and +4.75 mag respectively. The principle element of the system is a K3 giant star, nearing the end of its life. However, the fainter secondary green-blue star is itself a double - albeit a very difficult one. It will take telescopes in the 30-inch + class to split this second double. However, in coming years, this secondary element will become steadily easier to split with smaller instruments as the elements drift apart around their mutual gravitational centre - although it will be the mid-2020s before they are resolvable with 8-inch class telescopes. 

The main elements of Gamma Andromedae are gloriously split in most small telescopes. Even for those with the smallest of telescopes should have a go at splitting this star. 

Andromeda is, of course, home to the most prominent galaxy in the sky - M31 and its attendant satellite galaxies M32 and M110. As a major member of our Local Group of Galaxies, the M31 system is the largest gravitational influence on our own Milky Way and in under 4 Billion years it is likely the two Spirals will collide and eventually form a large Spheroid elliptical Galaxy. Approaching the Milky Way at around 300km per second, M31 is already a huge angular size - the boundaries of which stretch over 6 times the width of the Full Moon in the sky. At +3.4 mag, M31 was probably one of the rst Deep Sky objects - certainly the rst galaxy - to be noticed by humanity. First recorded by the great Persian Astronomer Abdul al-Rahman al-Su in his 962CE text “Book of Fixed Stars”, al-Rahman described M31 as the “Little Cloud” - and while his is the rst record of the object, it was doubtlessly noticed sooner, being the most prominent deep sky object alongside the Pleiades and Hyades in Taurus and M42 in Orion. 

Simon Marius first turned a telescope to M31 in 1612, though made no claim to its discovery - he may have been aware of it from earlier star charts - a Dutch example dating from 1500 shows the object. Throughout the 17th and 18th Centuries, the Galaxy was “re-discovered” independently by astronomers. While there was clearly communication between astronomers of the era regarding M31, many, including Edmund Halley, erroneously credited the discovery of the object to different people. Charles Messier credited its discovery to Marius, when forming his famous Messier list in 1764. Theories abounded as to the true nature of M31: a nascent Solar System forming, a cloud of glowing gas forming stars, a dying, decomposing star. Spectroscopy hinted at the true nature of M31. William Huggins , the early adopter of telescopic spectroscopy found that unlike many other nebulae, M31 exhibits a broad, continuous spectral response, rather than the definitive lined spectra of a gaseous nebula. Something that clearly set M31 apart from the likes of M42. In 1887, the first of many, many photographs of the galaxy was taken by Isaac Roberts from Crowborough in Sussex (just a short journey from the location of Telescope House in Edenbridge). Robert’s beautiful picture clearly shows dust lanes in the outer spiral arms and the satellite galaxies of M32 and M110, much as Mark Blundell’s more modern portrait does below.

 

M31 by Telescope House's Mark Blundell

Roberts subscribed to the theory that M31 was a Solar System in the early stages of formation. However, this theory was put to bed by mounting evidence of Novae observed and photographed within the reaches of M31. Heber Curtis discovered his first Nova in M31 in 1917 and went on to find a further 11. These were observed to be a mean of 10 magnitudes fainter than those observed within our own galaxy, leading to Curtis to suspect that M31 was considerably further away than first thought. Curtis was amongst those Astronomers that put forward the theory that objects of this type were “Island Universes”. This was famously debated in a meeting between Curtis and Harlow Shapely in 1920 - Curtis was for, Shapely against. 

The matter was settled in 1925 by Edwin Hubble, who discovered the first Cepheid Variable in M31. Comparisons with these variables and the Cepheids in our Galaxy proved that M31 was a separate conglomeration of stars, distinct from the Milky Way. Although underestimating the distance of M31 by a factor of two, Hubble proved that the Universe was a much larger and more mysterious place. 

Walter Baade, using the 200-inch Palomar Reflector discovered two separate types of Cepheids Variables in the population of M31, which had the effect of doubling Hubble’s pervious distance estimate in 1943. Current distance estimates are around the 2.5 million light years mark. M31 was also discovered to be heavily blueshifted in its spectral lines, proving via the Doppler effect that unlike the vast majority of galaxies in the sky, it is actually advancing towards us (or more accurately, both galaxies are attracting one another). 

M31 can be observed with (or without) all manner of optical equipment. It is probably best seen in large Binoculars (70mm objective size +) from a reasonably dark location. Rich field, short focal ratio telescopes like Dobsonians, and shorter Refractors show it well too, but due to its large angular size, powers must be kept low to see the Andromeda Galaxy in all its glory. Both satellite galaxies, M32 and M110 are easy to spot too (M32 the easier of the two). In larger instruments, with suitable filtration, it is possible to observe nebulous regions in M31 - similar features to the Orion Nebula in the Milky Way. This is a challenge, but a rewarding one! We’ll never see the true beauty of our own galaxy from the outside, so must content ourselves with the marvellous vista that M31 offers us. Some of M31’s globular clusters, including the remarkably large G1 are also visible though instruments of 10-inch aperture and above. 

However, it is in long duration photography that M31 really reveals its true extent and size. A 30 second unguided exposure with a wide field lens will easily show M31, though a small, high-quality refractor on an equatorial mount will be ideal in terms of framing the whole object on a standard DSLR chip. Multiple exposures, when stacked in a free program such as Deep Sky Stacker, will reveal the huge dust lanes and knotted, hydrogen rich areas of nebulosity. M31 is a prime beginner’s Deep Sky photographic target, but it is such a rewarding photographic object that Astrophotographers feel compelled to return to it time and time again. That it is well-placed for those of us in the northern hemisphere during the winter months is indeed fortuitous. All though observable through much of the year, now is the time to take full advantage of this fabulous Deep Sky wonder. 

To the western side of Andromeda, 2.5-degrees to the W of Iota Andromedae is the lovely NGC7662 - otherwise known as the Blue Snowball Nebula. This Planetary Nebula is a great object - albeit compact, at 0.5 minutes of arc - and is well seen in telescopes of most apertures. A 6-8-inch class telescope will show it clearly as a blue-green ball of light. However in larger telescopes, the subtleties of NGC7662 really become noticeable - it’s internal rings and slight elongated internal lobes can be distinct. The Blue Snowball can exhibit “blinking” just like the famous Blinking Planetary and Saturn Nebula. The Blue Snowball’s central white dwarf star shows distinct variability - peaking at +12 mag, but sometimes dimming down to below +16 mag. Current distance estimates put it at 5,600 light years distance from us and 0.8 light years in diameter. 

The Blue Snowball Nebula. Image Credit: HST/NASA/ESA.  Public Domain.

Drifting back east, beyond M31 and its companions, we come to two unusual objects. Mirach and Mirach’s Ghost are formed by Beta Andromedae and a condensed elliptical galaxy, NGC404. Line of sight from our perspective on Earth place these two completely unrelated objects in a very close pairing - they are separated by just under 7 arc minutes, making this galaxy easy to locate, but not necessarily so easy to see! Mirach has a tendency to overpower its neighbour, due the their differences in brightness. In clear, calm conditions NGC404 can be spotted in large binoculars, though telescopic observation can be a little trickier. Higher magnification can help under some conditions, though aperture will help as well. Photography of NGC404 is a challenge as well, but a worthwhile one. Mirach and Mirach’s Ghost are one of those interesting “Odd Couples” of the night sky, that perspective and chance throws our way. It would be a pity to let the perceived dificulty of observation stand in the way of taking a look. 

Another of Andromeda’s obscurer residents is the open cluster NGC752. Consisting of over 70 stars of around the 9th magnitude, NGC752’s cumulative magnitude stands at +5.7. Best seen in giant binoculars, this cluster has some particularly elderly residents for a star cluster: its A2-class stars indicate an age of over a billion years. The cluster is full of star chains and occupies an area of over 75 minutes of arc in the sky. It lies over 1500 light years from Earth. 

Just under 9 degrees to the SW of NGC752, just over the border in neighbouring Triangulum, forming an almost right-angled triangle in the sky with the cluster and the previously-mentioned Mirach and Mirach’s Ghost is the third largest member of our local group: M33, otherwise known as the Pinwheel (a description it unhelpfully shares with M101 in Ursa Major) or simply, the Triangulum Galaxy. Whereas M31 is inclined to our perspective, M33 is presented to us in a much more “face on” aspect. It is a smaller, less massive object than its neighbour, and occupies less area in the sky - M33’s major dimension is about as wide as M31’s narrowest. However, at it is still a major object, though its lower surface brightness make it more difficult to spot. 

M33 by Telescope House's Mark Blundell

At +5.69 mag M33 is technically visible to the naked eye, but one would have to be in a particularly dark location and very well dark-adapted in order to see it unaided Discovered in 1654 by Giovanni Batista Hodeierna and then independently re-discovered and catalogued by Charles Messier in 1764, large binoculars will show M33 very well from a good locale and larger aperture observations can reveal some of the brighter nebulous regions. The largest and most prominent of these was first recorded by William Herschel in 1784 and now known as NGC604. As previously mentioned with M31, these two galaxies (setting aside the satellite Magellanic Clouds of our own Milky Way) are the only two external systems in which it is possible to view nebulous regions visually through a reasonably-sized telescope. H-Alpha and H-Beta Filters will help considerably with this endeavour - though inevitably, aperture and a good sky is key. Those with access to instruments in the 16-inch or above class would be able to spot some of M33’s globular clusters, arranged in a halo around the galaxy, much as they are in our own Milky Way. 

Current measurements put M33 at a distance of around 3 million light years away from us - 500,000 light years further from us than M31. M33 contains around 30-40 billion stars, less than our galaxy’s 200-400 billion and much less than M31’s trillion stars. M33 has supposedly interacted with M31 in the distant past, and as it is moving towards us and M31, will probably do so again. Whether this results in a collision such as that predicted for the Milky Way and M31 is, as yet, unknown.