LMC 5 Supergiant Shell

The Cloud’s most fascinating and lovely supernova remnant resides in LMC 5

Image credit & copyright: Team Ciel Austral

RA: 05h 22m Dec: -66° 00′

Diameter: 2,600 light-years

OB Associations: LH 45

NGC Objects: NGC 1925, 1933, 1941

Supergiant Shell LMC 5

LMC 5 is located directly to the northwest of LMC 4. Interestingly, no OB associations lie in LMC 5’s shell interior; OB association LH 45 lies along the shell’s northern rim. Long Ha filaments lie along the southern and western sides of the shell. (Book et al, 2009). And its eastern side is spectacular, for the bright N48 region is the impact zone where the smaller LMC 5 is colliding with its gargantuan neighbour, LMC 4.

Although the SGS only has a handful of objects to observe (most of which are very small clusters, apart from the attractive LH45/N45 complex), it more than makes up for this paucity by hosting what is surely one of the Cloud’s most fascinating objects to observe with a telescope of any size – the beautifully bright supernova remnant, N49. Interestingly, Fujii et al (2018) determined that whereas the rich star-forming region N48 is located right at the interaction zone of the two SGSs, the superb SNR N49, is actually associated with LMC 5 alone. They found that the N48 region’s star formation is relatively evolved, whereas the N49 region’s star formation is quiet.

Low magnification overview

Because LMC 5 is not stuffed to capacity with objects like some of the other supergiant shells, one’s attention is grabbed by the bright impact zone, N48, where the SGS is colliding with LMC 4, its garganutan neighbour to its southeast. But dragging one’s eyes away from this fascinating region, one can see the beautiful little supernova remnant, N49, to its north. Even at low magnification, the faint, small, strangely triangular-shaped scrap of stellar debris is obvious.

The star cloud, LH 45 = NGC 1925, lying on the supergiant shell’s northern periphery, is a beautiful congregation of stars – a few brighter stars, masses of fainter stars, and the faint miasmic glow of unresolved stars. To its north there is the very faintest hint of N43 to the western side, but it requires the use of the UHC filter to bring it out, at which time it appears as a very faint and patchy mist. NGC 1933 appears as a tiny droplet of faint starlight, and NGC 1941 as another droplet of fainter, mistier starlight.

N49 Supernova Remnant

An exquisite little SNR

N49

N49 Supernova Remnant

An exquisite little SNR

N49

LH 45 Star Cloud

A lovely star cloud

LH 45

LH 45 Star Cloud

A lovely star cloud

LH 45

N35 + BSDL 1126 (H II Region + Open Cluster)

RA 0517 52.0 Dec -66 05 42 Mag – Size –

16″ at 228x: BSDL 1126 appears very faint, stellar; no sign of N35 with the UHC filter.

BSDL 1126

KMHK 723 (Open Cluster)

RA 05 17 52.4 Dec -66 04 23 Mag – Size 0.9ʹ x 0.8ʹ

16″ at 228x: KMHK 723 appears as a faint, smooth round knot of stars, ~12″ in diameter.

KMHK 723

HS 229 (Open Cluster)

RA 05 19 43.2 Dec -66 14 45 Mag – Size 0.8′ x 0.6′

16″ at 228x: HS 229 appears as a faint and exceedingly small, round, droplet of unresolved stars.

HS 229

KMHK 800 (Open Cluster)

RA 052102.7 Dec -66 03 09.9 Mag – Size 0.6‘

16″ at 228x: KMHK 800 appears as a faint and exceedingly small, round, bead of pale light.

KMHK 800

SL 409 (Open Cluster)

RA 052137.0 Dec -65 29 18 Mag – Size 0.5ʹ x 0.45ʹ

16″ at 228x: It’s always a treat when a somewhat innocuous cluster forms part of an attractive stellar sky-picture with another object. SL 409 lies at the NW end of a row of four stars that form one arm of a conspicuous and wide V-shaped asterism of eight stars (open to the SW) within which lies NGC 1933 (5.5′ SE of SL 409). SL 409 appears as a faint, roundish and very hazy, cluster, ~20″ in diameter. One small star lies in that tantalizing glow of unresolved stars.

SL 409

NGC 1933 (Open Cluster)

RA 05 22 27.3 Dec -66 09 08 Mag 11.8 Size 1.2ʹ

16″ at 228x: Lying in a conspicuous V-shaped asterism of 8 stars (open to the SW and with the small cluster SL 409 lying at the NW end), NGC 1933 appears fairly bright, round, ~45″ in diameter, an even glow with trim edges. No stars are resolved.

NGC 1933

SL 421 (Open Cluster)

RA 0522 29.2 Dec -66 31 41 Mag – Size 1.20ʹ x 1.10ʹ

16″ at 228x: This cluster appears as a fairly faint, very small, round, knot of stars surrounded by a small and faint halo of unresolved starlight.

SL 421

NGC 1941 + N46 (Open Cluster + Emission Nebula)

RA 05 23 07.4 Dec -66 22 41 Mag 12.0 Size 0.9ʹ

16″ at 228x: For its size, NGC 1941 is an attractive little object. It appears as a fairly faint, round cluster, 30″ in diameter, surrounded by a very faint N-S egg-shaped haze of nebulosity (N46). Three very small stars are resolved. The nebulosity has a good response to the UHC filter, appearing smooth and round with surprisingly well-defined edges.

NGC 1941

BSDL 1456 (Open Cluster)

RA 05 23 12.0 Dec -66 25 00 Mag – Size –

16″ at 228x: BSDL 1456 appears as a couple of faint, stellar pinpoints to the northeast of mag 10 star HD 269435.

BSDL 1456

N48E = NGC 1945 (SNR)

RA 05 24 18.9 Dec -66 23 33 Size 2.4′ Age –

16″ at 228x + OIII filter: Without a filter, SNR J0524-6623 appears as a faint gossamer haze, irregularly shaped, ~30″ in diameter with soft, hazy edges that fade out into the sky. It appears marginally brighter along its southern edge. It has a good response to the OIII filter, appearing somewhat less hazy and more glowing, and its southern edge is definite and fairly sharp.

N48E = NGC 1945

NGC 1946 (Open Cluster)

RA 05 25 15.4 Dec -66 23 39 Mag 12.9 Size 1.0′ x 0.9′

16″ at 228x: Lying only 2′ SW of the small glow of N48D, NGC 1946 appears as a bright, irregularly round, glow, 25″ in diameter. No resolved stars, although it is surrounded by lovely little grouping of stars.

N48D (Emission Nebula)

RA 05 25 27.4 Dec -66 21 52 Mag – Size 0.9′

16″ at 228x + UHC filter: N48D appears as a faint, nebulous knot, ~20″ in diameter.

NGC 1946 + N48D

SL 463 (Open Cluster)

RA 05 26 16.0 Mag -66 03 10 Mag 12.4 Size 1.1′ x 1.0′

16″ at 228x: SL 463 lies 2.4′ NE of the SNR N49, and the small knot of stars makes a lovely visual contrast with the ghostly SNR. The cluster appears as a pretty bright, asymmetrical knot, ~22″ in diameter, attached to a small star on its northeast side. No other stars are resolved.