Big, Bright & Beautiful in January
By Max Gardner AM
This month we have a lot going for us. Holidays (for many), warm weather and a night sky with some pretty marvelous things to look at all makes for great observing. Even the weather should be accommodating, so lets not waste the opportunity. With so much to see along the meridian tonight at 10pm, lets get out and get started.
Right on the northern meridian, east of the Hyades which we examined last month, is the 4th magnitude star Zeta Tauri, where, a degree to the northwest, lies the 8th magnitude nebula M1. This appears as an oblong patch that will show considerable surface mottling, even some swirling structure with larger apertures. It is believed to be the remains of a supernova explosion recorded by Chinese observers around the 10th century AD.
Moving straight up (south) we come to the constellation of Orion. Its three prominent belt stars Alnitak, Alnilam and Mintaka and the suspended dagger, form the familiar pot asterism which itself lies within the bright trapezium of stars Betelgeuse, Bellatrix, Saiph and Rigel. These mark the shoulders and knees of Orion's body. Betelguese is one of the physically largest stars in our galaxy, a cool red supergiant that is a very spectacular orange colour in the telescope. If it were to replace the Sun, it would stretch beyond the orbit of Mars. Equally spectacular is dazzling Rigel, although it is a very hot, blue supergiant, some 50,000 times brighter than the Sun! Rigel has a smaller 6th magnitude companion that can be seen in most scopes using high power.
The brighter deep sky objects in Orion are very well known and easy to find. Lets start with M78, which lies slightly to the northeast of the belt stars. It is a fairly bright nebula surrounding two stars, showing haze with some structure. Larger apertures may see a second, fainter nebula, NGC 2026, just to the northwest of the field of M78. If we look in the area of the belt we will find patches of fairly tenuous nebulosity, best seen around the central belt star, Alnilam. In the field of the southernmost belt star, Alnitak, is the very interesting nebula NGC 2024. This shows a bright, elongated, structured outer circumference with a dark central area, giving rise to the popular name "The Flame Nebula" which it truly resembles.
Less than half a degree south is the faint nebula IC 434 which contains the famous dark object "The Horsehead Nebula", classified as the dark nebula Barnard 33. I mention it out of interest as it is a difficult object, too faint for these articles, but too well known to skip! Almost in the same low power field is the spectacular multiple star Sigma Orionis. Larger apertures will resolve it into four separate stars, roughly aligned, showing some colour, a most interesting object.
As we move south along the dagger we come to the mighty nebula M42, "The Great Nebula in Orion", too well known to need any description. Simply admire the great wing-like shape, faint hint of colour and any delicate details that your instrument can reveal. Most apertures will show the bright group of four closely placed stars within the nebula - this is the famous multiple star Theta Orionis, well known as "The Trapezium." Larger apertures may detect a fifth and even a sixth component in excellent seeing conditions. Just below M42 (north) is another small nebula NGC 1977, usually seen in the same field. Just above M42 (south) is another nebula NGC 1980, which I saw as: "very bright nebulosity surrounding a bright scattered group of stars. The group includes a double star magnitudes approximately 5 and 8". Further up, forming the tip of the dagger, are two fainter nebulae, NGC 1999 and IC 430 that will be seen in larger apertures.
Our next target is just across the border in the constellation of Lepus, immediately south of Orion, where we encounter the planetary nebula IC 418, which most scopes should see. I used high power and recorded: "A very small gray ball - very planet-like. Closer inspection shows a bright central star magnitude 10, with soft surrounding haze. There is almost a blinking effect." Well south in Lepus, near the border of the constellation Columba and forming the southern head of an equilateral triangle with the stars Beta and Epsilon Lepi, is the fine 8th magnitude globular cluster M79. My observing notes say "Highly resolved, slightly flattened, with a dense, resolved small core, and very bright resolved edges. There is an arc of stars just to the west of the field. An interesting object".
Due south, in the constellation Columba, close to the border with the constellation Caelum, is an interesting 10th magnitude spiral galaxy, NGC 1808, of which I recorded: "A fine elongated galaxy with a small bright bar and an extensive, thick disk which contains arms, knots and two small dust lanes."
Three degrees south, in the southwest corner of Columba is another bright, resolved globular cluster NGC 1851. My notes state: "A fine, small globular. It has a very dense, small core surrounded by a wide halo of partly resolved faint stars. The edge is slightly flattened on the west side. Several brighter stars are scattered across the face."
It is time to resume our exploration of the Large Magellanic Cloud. Last month we stopped at the centrally located navigation marker, the easily recognised cluster NGC 1910 with its S-shaped surrounding nebula. It stands out well in a busy area of the Bar. Moving north and east we come upon the bright stellar association, star cloud and group of nebulae designated as NGC 1929/34/35/36/37. All are located in close proximity and there is little point in trying to sort out which is which. In effect we see a large area of bright resolved stars (the association) surrounding a star cloud (a mass of tiny resolved stars) with patches of bright and dim nebulae threaded throughout. An O-11 filter will brighten things up well and reveal a most interesting field. Higher power will reveal much delicate detail.
Moving slightly northwest will bring into view another interesting complex NGC 1955/68/74. Here we have no less than three stellar associations in a single low power field, well resolved with many bright stars, located in a line running across the field from south-west to north-east. There is nebulosity throughout as my notes record: "A large area of clusters and nebulae. NGC1968 contains bright stars magnitude 11 forming a triangle. There are large nebulous clumps around the triangle points. Nebulae show throughout with much structure. NGC 1955 is a very bright, intense, round cluster to the south. NGC 1974 to the north is smaller and fainter. An O-111 filter reveals an oval band of nebula surrounds the whole complex. A great area."
Due south by almost one and a half degrees we come to the complex NGC 1962/65/66/70, yet another example, in my opinion, of almost over-zealous numbering. Here we have a single, massive stellar association in which are several bright aggregations of stars, each bearing a separate NGC number, with bright patches of nebulosity throughout, all in a single field. A very bright and busy area much enhanced by the O-111 filter.
Our next target is about one and a half degrees northeast, away from the Bar, where we find the complex NGC 2014/20. NGC 2014 is a large star cluster with nebulosity, while NGC 2020 is a bright nebula adjacent to the east. My notes record: "A huge area with complex structure and dark lanes, especially when seen with the O-111 filter. There are strange shapes and brightness variations, with many resolved stars in the nebulosity. The O-111 filter emphasizes the nebulosity and nearly doubles the apparent size. A very fine object!" Nudge the scope slightly to the northeast and you will be on another bright complex, NGC 2029/32/35/40. The first three numbers cover what is known by some as "The Seagull Nebula" for its unmistakable shape. My notes say: "a very spectacular, complex structure, reminiscent of the Tarantula Nebula. It seems to be a radiation-driven bubble nebula with curves, streamers, twisting strands and wide variation in brightness." NGC 2040 is a stellar association, also wreathed in nebulosity, lying very close to the east. Don't miss them.
Moving due south, well below the Bar, we encounter NGC 2018, somewhat less bright but large and interesting. My notes record: "A large stellar association which has resolved stars of magnitude 11-13. The nebulosity is on the east side of the association, in a boomerang shape. An O-111 filter enhances it and shows some structure. Best seen at lower power. A good object."
Moving north through the Bar and slightly west we come to the biggest and brightest complex in the LMC, indeed the largest and brightest nebula yet discovered in the entire universe, NGC 2070 "The Tarantula Nebula". This fantastic object needs no description from me, save to say that, in my scope at high power with an O-111 filter on a good night, this apparition assumes a frightening, three-dimensional resemblance to its namesake, almost seeming to crawl up the eyepiece tube! At the centre of the nebula is a bright star cluster containing the bright stellar object 30 Doradus. Once thought to be the most massive star ever discovered, 30 Doradus has recently been resolved by the Hubble Space Telescope into a cluster of individual stars. Move the scope slightly in any direction around the Tarantula and you will find dozens of smaller clusters and nebulae. Truly a great area.
Less than a third of a degree due south of the Tarantula is our final area containing the objects NGC 2077/78/79/80/83/85/86. In the telescope, these appear as two adjacent complexes located north and south of each other. To the south is a large stellar association with general nebulosity and four brighter hazy patches. Slightly to the north are three nebulous patches with resolved stars embedded and adjacent. Together, they make a bright and fitting close to our tour.
I hope these notes have whetted your appetite to continue to explore the fabulous richness of the LMC. We have visited some of the largest and brightest areas, but have seen no more than the tip of an iceberg. There is far more awaiting those who press on, gaining familiarity with the plethora of objects in the Cloud. All you need is sufficiently detailed charts, such as those in the Herald Bobroff Astroatlas. Having derived immense pleasure from exploring the Cloud myself, I can only encourage others to get to know the LMC intimately. You will be well repaid.