Paddy
06-01-2013, 08:13 PM
With some clear skies and no other commitments, I've been able to put together the first of my "tours" of the LMC. I think there will be at least 4. This first one starts at the spectacular area around the Tarantula nebula, NGC 2070. The preamble is for those not familiar with star hopping.
You will find the chart Inset A (http://www.cloudsofmagellan.net.au/lmcinseta.htm) from my site Clouds of Magellan (http://www.cloudsofmagellan.net.au/)useful for this tour - even if you use go-to or Argo Naves.
This tour will also soon be posted at Clouds of Magellan (http://www.cloudsofmagellan.net.au/).
Hope you find it helpful. Let me know if there are any bugs or improvements you can suggest.
Large Magellanic Cloud Tour #1 – NGC 2070/Tarantula Area
As the LMC changes it’s orientation as it circles the South Celestial Pole (SCP), I will us the terms preceding (p) and following (f) instead of West and East respectively. Preceding is the side of the field of view that objects move towards, following is the side they move from. I use the term North to mean away from the pole and South to mean towards the pole. So the Tarantula nebula is always North of the LMC bar in the notoation.
It will also help if you know the field of view of your eyepieces. This will help you find the angular distance between the object in minutes. If you’re not familiar with how to calculate this, it is the apparent field of view of your eyepiece (eg 80 degrees for a Nagler) divided by the magnification in your scope and multiplied by 60 to give the result in minutes. The magnification is the focal length of your scope divided by the focal length of the eyepiece.
A magnified finderscope will be very helpful in getting started, but otherwise a wide-field eyepiece should suffice. These notes have been made using a 16” F4.9 telescope under dark skies. Some of the fainter objects may not be visible using smaller scopes or with light-polluted skies. A 10-12” scope under good conditions should be enough to see just about all of these objects and an 8” will see most of them.
This first “tour” covers objects in the area around the Tarantula Nebula, NGC 2070. This area is perhaps one of the richest and most stunning areas of sky to view with an amateur telescope. It is so rich in Deep Sky Objects that it can be a bit overwhelming. Take time and enjoy the views.
Inset A of the LMC charts at cloudsofmagellan.net.au will be a useful guide for this tour.
Getting Started. If you’re new to this area of sky, the first task is to find the Tarantula Nebula NGC 2070. At a dark site, you may be able to see it with unaided eyes as a bright knot to the North of following end of the bar of the LMC. With binoculars or a magnified finderscope, it will really stand out as the brightest element of the whole LMC. At 135x it is an extraordinarily intricate maze of nebulosity and dark lanes, some very delicate like folds in this amazing object spanning over 20’ (without UHC filter – it looks much more extended with a filter). It does resemble a southward-pointing tarantula with the abdomen north most (formed by the N-S oval of emission nebula NGC 2069). Somewhere around the head of the spider you will note the bright “star” R136 – a cluster of 450,000 solar masses. Some of it’s constituent stars are 150x the mass of the sun. With good conditions you may see what appears to be a ring of stars around the central brightness of this cluster.
To the “east” 20’ following R 136 is the spectacular open cluster NGC 2100, a 4’ roughly round, bright splash of stars and haze. About 6’ preceding and slightly to the south is open cluster NGC 2092, a small 1’ dia round glow with perhaps a few stars resolvable with averted vision. 8’ N of NGC 2100 is the diffuse patchy haze (10’x5’) of Hodge-Sexton association 397 with a few scattered resolvable stars. Several knots light up in this association with UHC filter and the whole thing becomes more distinct.
A line drawn from NGC 2092 through NGC 2100 and extended for 12’ brings us to the small soft glow of open cluster NGC 2108
To the South and glorious sights Come back to NGC 2070 and R136 10’ S-p of R 136 is the intriguing 4’x2’ crescent-shaped glow of open cluster and emission nebula NGC 2060. About 8 resolved stars pick out the convex ridge of luminosity on the S-f side of the crescent. Nebulosity in the space enclosed by the crescent lights up with UHC filter, but remains dimmer than the crescent.
For this next bit, make sure you have your widest field of view eyepiece in the focuser. In a 1 degree field with NGC 2070 at the north end of the field, NGC 2100 can be seen at the following edge and the gorgeous, sinuous NGC 2074 in the centre. A line extended S from NGC 2070 through NGC 2074 leads to the nebula complexes around NGC 2077 (Henize 160) and NGC 2078 (Henize 159). Between NGC 2074 and NGC 2070 is a 40’ long broad splash of myriad stars and luminosity from NGC 2081 (following) through Lucke-Hodge association 93&94 to LH 87-84 preceding.
It’s well worth taking some time to absorb this vista at low power before tackling it step-by-step at a higher power.
30’ S of R136, the backward S-shaped emission nebula NGC 2074 is a very useful landmark in this area and a very beautiful object in its own right. At 175x it is an elegant 1’ thick strip of haze and stars forming two joined counter arcs spaning 6’ Sf-Np x 4’ Sp-Nf. The Sf arc is thicker and brighter, the Np arc is more tightly arced. About 10 stars pick out the elegant counter curves. Both curves brighten with UHC filter and nebulosity surrounding them also becomes apparent.
About 5’ Nf NGC 2074 is the large open cluster and emission nebula NGC 2081, rich with stars and complex patterns of luminosity(1/3 of the way from NGC 2074 to NGC 2100). This is worth spending some time observing as more intricate shapes emerge from the nebulosity. To my eye, there is a nearly complete ring of haze and stars about 4’ across at the Nf side of the nebula and a 3’ wedge lies closer to NGC 2074. These patterns become more distinct, expansive and intricate with a UHC filter.
10’ S of NGC 2074 is a close pair of bright knots the Nf one being the larger and brighter emission nebula NGC 2077. At 175x in my scope, NGC 2077 looks like a triangular aggregate of 3 small nots and looks 1.5’ across. The fainter of the pair is emission nebula NGC 2080 which looks a magnitude dimmer than 2077 and about half the size.
Even without a UHC filter, it’s easy to see that NGCs 2077 and 2080 are part of a larger area of nebulosity stretching about 7’ to the f and about 3-4’ wide. The bright knot of emission nebula IC 2145 is clear at the following edge of this tract and several other patches of luminosity are also apparent. The most obvious of these is emission nebula NGC 2086. All brighten with UHC filter and NGC 2085 becomes more obvious. With the filter, the large tract of nebulosity appears to extend to the f of IC 2145.
About 4’ south of this complex is a 6’ square aggregation of glowing knots, the brightest of which is emission nebula NGC 2079 at the Sp corner and looks about 1’ across. To my eye, the arc of NGC2084 at the Sf corner and NGCs 2083 & 2078 appear to form a backward P shape. The whole complex brightens and looks clumpier with UHC filter. A small glow at the Sf corner of the complex, Henize emission nebula N159E is visible without UHC filter. About 12’ to the p, emission nebula NGC 2052 is a faint 2’x1’ glow.
As mentioned above, there are two large tracts of stars and nebulosity to the south of NGC 2070. The smaller of the two precedes the area from NGCs 2074 to 2079, measuring 25’x10’ and starting 20’ Sp from NGC 2074. About 40 resolved stars are spread across a background of patchy haze. Near the f end is emission nebula NGC 2048, a 1.5x1’ f-p oval smooth glow. At the preceding end of the complex, open clusters NGC 2033 & 2037 are small and bright, almost stellar objects and appear as either end of a line of four “stars”.
The larger tract starts between NGC 2060 and NGC 2074, extends 25’ to the Sp and is about 14’ wide. Hundreds of stars of varying magnitude are splashed across a faint, patchy haze. Sitting on the northern edge of the tract towards the preceding end is open cluster NGC 2050 (aka Lucke-Hodge association 93). This is a 3’ dia round glow with half a dozen stars around the circumference and none in the centre. On the SP edge are two brighter stars.
Also towards the p end of this tract, but on the southern edge is open cluster NGC 2055/LH94. To me this looks like a 2.5x1.5’ curved p-f line of stars and haze. According to the Night Sky Observer’s guide, which lists this as a star cloud, John Herschel originally described this as a large object, perhaps meaning the whole tract or a larger element at this end of it and contrasts this with the Uranometria Deep Sky Field Guide’s listing of it as 0.6’.
The larger tract is less clear – NGC 2055 is a bright knot on the southern-preceding edge of the tract. What this object actually includes seems a matter of uncertainty
To the “west” Return to NGC 2060 just on the Sp side of NGC 2070. 10’ preceding 2060 is a boomerang-shaped glow with resolved stars about 3’x1.5’. The following half of the boomerang is significantly fainter. This is open cluster and nebula NGC 2044 (also listed as Lucke/Hodge 90). Just to the p side is a 3’x1’ N-S line of haze and stars. The two make a very interesting figure. Steve Gottlieb’s notes on the NGC/IC project web site note that 2044 harbours a supernova remnant. A UHC filter show them to be part of a large tract of nebulosity extending 30’ Sp from NGC 2070.
20’ from the Np edge of NGC 2070 is a 14’x7’ blaze of at least 60 stars and patchy luminosity. This is open cluster NGC 2042. Some of the patches brighten with UHC filter. To its north is the very obvious 2’ smooth round glow of open cluster SL 697.
14’ Nf NGC 2070 is a 7’x3’ irregular glow with about 10 visible stars – NGC 2093. The size of the haze associated with this object increases with UHC filter.
You will find the chart Inset A (http://www.cloudsofmagellan.net.au/lmcinseta.htm) from my site Clouds of Magellan (http://www.cloudsofmagellan.net.au/)useful for this tour - even if you use go-to or Argo Naves.
This tour will also soon be posted at Clouds of Magellan (http://www.cloudsofmagellan.net.au/).
Hope you find it helpful. Let me know if there are any bugs or improvements you can suggest.
Large Magellanic Cloud Tour #1 – NGC 2070/Tarantula Area
As the LMC changes it’s orientation as it circles the South Celestial Pole (SCP), I will us the terms preceding (p) and following (f) instead of West and East respectively. Preceding is the side of the field of view that objects move towards, following is the side they move from. I use the term North to mean away from the pole and South to mean towards the pole. So the Tarantula nebula is always North of the LMC bar in the notoation.
It will also help if you know the field of view of your eyepieces. This will help you find the angular distance between the object in minutes. If you’re not familiar with how to calculate this, it is the apparent field of view of your eyepiece (eg 80 degrees for a Nagler) divided by the magnification in your scope and multiplied by 60 to give the result in minutes. The magnification is the focal length of your scope divided by the focal length of the eyepiece.
A magnified finderscope will be very helpful in getting started, but otherwise a wide-field eyepiece should suffice. These notes have been made using a 16” F4.9 telescope under dark skies. Some of the fainter objects may not be visible using smaller scopes or with light-polluted skies. A 10-12” scope under good conditions should be enough to see just about all of these objects and an 8” will see most of them.
This first “tour” covers objects in the area around the Tarantula Nebula, NGC 2070. This area is perhaps one of the richest and most stunning areas of sky to view with an amateur telescope. It is so rich in Deep Sky Objects that it can be a bit overwhelming. Take time and enjoy the views.
Inset A of the LMC charts at cloudsofmagellan.net.au will be a useful guide for this tour.
Getting Started. If you’re new to this area of sky, the first task is to find the Tarantula Nebula NGC 2070. At a dark site, you may be able to see it with unaided eyes as a bright knot to the North of following end of the bar of the LMC. With binoculars or a magnified finderscope, it will really stand out as the brightest element of the whole LMC. At 135x it is an extraordinarily intricate maze of nebulosity and dark lanes, some very delicate like folds in this amazing object spanning over 20’ (without UHC filter – it looks much more extended with a filter). It does resemble a southward-pointing tarantula with the abdomen north most (formed by the N-S oval of emission nebula NGC 2069). Somewhere around the head of the spider you will note the bright “star” R136 – a cluster of 450,000 solar masses. Some of it’s constituent stars are 150x the mass of the sun. With good conditions you may see what appears to be a ring of stars around the central brightness of this cluster.
To the “east” 20’ following R 136 is the spectacular open cluster NGC 2100, a 4’ roughly round, bright splash of stars and haze. About 6’ preceding and slightly to the south is open cluster NGC 2092, a small 1’ dia round glow with perhaps a few stars resolvable with averted vision. 8’ N of NGC 2100 is the diffuse patchy haze (10’x5’) of Hodge-Sexton association 397 with a few scattered resolvable stars. Several knots light up in this association with UHC filter and the whole thing becomes more distinct.
A line drawn from NGC 2092 through NGC 2100 and extended for 12’ brings us to the small soft glow of open cluster NGC 2108
To the South and glorious sights Come back to NGC 2070 and R136 10’ S-p of R 136 is the intriguing 4’x2’ crescent-shaped glow of open cluster and emission nebula NGC 2060. About 8 resolved stars pick out the convex ridge of luminosity on the S-f side of the crescent. Nebulosity in the space enclosed by the crescent lights up with UHC filter, but remains dimmer than the crescent.
For this next bit, make sure you have your widest field of view eyepiece in the focuser. In a 1 degree field with NGC 2070 at the north end of the field, NGC 2100 can be seen at the following edge and the gorgeous, sinuous NGC 2074 in the centre. A line extended S from NGC 2070 through NGC 2074 leads to the nebula complexes around NGC 2077 (Henize 160) and NGC 2078 (Henize 159). Between NGC 2074 and NGC 2070 is a 40’ long broad splash of myriad stars and luminosity from NGC 2081 (following) through Lucke-Hodge association 93&94 to LH 87-84 preceding.
It’s well worth taking some time to absorb this vista at low power before tackling it step-by-step at a higher power.
30’ S of R136, the backward S-shaped emission nebula NGC 2074 is a very useful landmark in this area and a very beautiful object in its own right. At 175x it is an elegant 1’ thick strip of haze and stars forming two joined counter arcs spaning 6’ Sf-Np x 4’ Sp-Nf. The Sf arc is thicker and brighter, the Np arc is more tightly arced. About 10 stars pick out the elegant counter curves. Both curves brighten with UHC filter and nebulosity surrounding them also becomes apparent.
About 5’ Nf NGC 2074 is the large open cluster and emission nebula NGC 2081, rich with stars and complex patterns of luminosity(1/3 of the way from NGC 2074 to NGC 2100). This is worth spending some time observing as more intricate shapes emerge from the nebulosity. To my eye, there is a nearly complete ring of haze and stars about 4’ across at the Nf side of the nebula and a 3’ wedge lies closer to NGC 2074. These patterns become more distinct, expansive and intricate with a UHC filter.
10’ S of NGC 2074 is a close pair of bright knots the Nf one being the larger and brighter emission nebula NGC 2077. At 175x in my scope, NGC 2077 looks like a triangular aggregate of 3 small nots and looks 1.5’ across. The fainter of the pair is emission nebula NGC 2080 which looks a magnitude dimmer than 2077 and about half the size.
Even without a UHC filter, it’s easy to see that NGCs 2077 and 2080 are part of a larger area of nebulosity stretching about 7’ to the f and about 3-4’ wide. The bright knot of emission nebula IC 2145 is clear at the following edge of this tract and several other patches of luminosity are also apparent. The most obvious of these is emission nebula NGC 2086. All brighten with UHC filter and NGC 2085 becomes more obvious. With the filter, the large tract of nebulosity appears to extend to the f of IC 2145.
About 4’ south of this complex is a 6’ square aggregation of glowing knots, the brightest of which is emission nebula NGC 2079 at the Sp corner and looks about 1’ across. To my eye, the arc of NGC2084 at the Sf corner and NGCs 2083 & 2078 appear to form a backward P shape. The whole complex brightens and looks clumpier with UHC filter. A small glow at the Sf corner of the complex, Henize emission nebula N159E is visible without UHC filter. About 12’ to the p, emission nebula NGC 2052 is a faint 2’x1’ glow.
As mentioned above, there are two large tracts of stars and nebulosity to the south of NGC 2070. The smaller of the two precedes the area from NGCs 2074 to 2079, measuring 25’x10’ and starting 20’ Sp from NGC 2074. About 40 resolved stars are spread across a background of patchy haze. Near the f end is emission nebula NGC 2048, a 1.5x1’ f-p oval smooth glow. At the preceding end of the complex, open clusters NGC 2033 & 2037 are small and bright, almost stellar objects and appear as either end of a line of four “stars”.
The larger tract starts between NGC 2060 and NGC 2074, extends 25’ to the Sp and is about 14’ wide. Hundreds of stars of varying magnitude are splashed across a faint, patchy haze. Sitting on the northern edge of the tract towards the preceding end is open cluster NGC 2050 (aka Lucke-Hodge association 93). This is a 3’ dia round glow with half a dozen stars around the circumference and none in the centre. On the SP edge are two brighter stars.
Also towards the p end of this tract, but on the southern edge is open cluster NGC 2055/LH94. To me this looks like a 2.5x1.5’ curved p-f line of stars and haze. According to the Night Sky Observer’s guide, which lists this as a star cloud, John Herschel originally described this as a large object, perhaps meaning the whole tract or a larger element at this end of it and contrasts this with the Uranometria Deep Sky Field Guide’s listing of it as 0.6’.
The larger tract is less clear – NGC 2055 is a bright knot on the southern-preceding edge of the tract. What this object actually includes seems a matter of uncertainty
To the “west” Return to NGC 2060 just on the Sp side of NGC 2070. 10’ preceding 2060 is a boomerang-shaped glow with resolved stars about 3’x1.5’. The following half of the boomerang is significantly fainter. This is open cluster and nebula NGC 2044 (also listed as Lucke/Hodge 90). Just to the p side is a 3’x1’ N-S line of haze and stars. The two make a very interesting figure. Steve Gottlieb’s notes on the NGC/IC project web site note that 2044 harbours a supernova remnant. A UHC filter show them to be part of a large tract of nebulosity extending 30’ Sp from NGC 2070.
20’ from the Np edge of NGC 2070 is a 14’x7’ blaze of at least 60 stars and patchy luminosity. This is open cluster NGC 2042. Some of the patches brighten with UHC filter. To its north is the very obvious 2’ smooth round glow of open cluster SL 697.
14’ Nf NGC 2070 is a 7’x3’ irregular glow with about 10 visible stars – NGC 2093. The size of the haze associated with this object increases with UHC filter.