N154 Superbubble

A great, sprawling superbubble

Image credit Robert Gendler

Central Coordinates:

RA: 05h 35m Dec: -69° 43′

Diameter: 590 x 390 light-years

OB Associations: LH 81, 87

NGC Objects: NGC 2033, 2037, 2048

N154 offers visitors a beguiling observation

Lying on the southwestern periphery of the vast and opulent supergiant shell LMC 2, this superbubble, measuring an enormous 590 x 390 light-years in size, offers observers a beguiling visit with the rich open splash of two OB association’s stars, LH 81 and LH 87, encased in an oddly “mismatched” glow of nebulosity that shows as a lovely arc-shaped glow to the southwest and a rough, smudgy-shaped glow to the northeast.

At low magnification one certainly gets an idea of its enormity. It sprawls across the FOV, full of stars, and its two swathes of curving nebulosity delineate its almost-oval superbubble-shape.

N154… not only an unusual superbubble to explore, but it lies alongside some of the Cloud’s richest real estate with the Tarantula Nebula out of sight at the top left and the incredible LMC 2 to the image’s left. Credit: ESO

LH 81 = NGC 2033 (OB Association)

RA 05 34 43.0 Dec -69 44 12 Mag 11.6 Size 5.5′ x 4.5‘

16″ at 228x: This is a gorgeous, rich cloud of stars, 5′ in diameter with close to 20 mag 11-14 stars resolved. The cluster BSDL 2441 marks the northern side and appears as a fairly bright haze of unresolved stars, ~20″ elongated N-S, with a mag 14 star resolved at its north end. BSDL 2426 marks the southern side and appears as a bright streak of starlight, ~20″ elongated WNW-ESE and with mag 12.9 HD 269769 on its south-southwest end (it’s also one of the nebula’s ionizing stars). BCDSP 8, is often taken as NGC 2037, and appears as a bright, round, compact knot, ~20″ in diameter, with no stars resolved. Two Wolf-Rayet stars, mag 13.2 Brey 50 and mag 14.1 Brey 53, round out the stellar picture in exotic fashion.

N154B (Emission Nebula)

RA 05 34 33.1 Dec -69 47 14 Mag – Size –

16″ at 228x: Without a filter, N154B’s faint and diffuse nebulosity curves around the southern side of LH 81. The nebulosity has a great response to the UHC filter, appearing as a ~7′ curving swathe, elongated E-W. The glow is smooth and even, but somewhat brighter on the eastern half, and has lovely hazy edges.

LH 87 (OB Association)

RA 05 35 01.0 Dec -69 43 42 Mag – Size 7′ x 5′

16″ at 228x: LH 87 is also a lovely rich cloud of stars. Separated by a narrow and almost starless patch from LH 81’s northeast side, it stretches ~6′ x 4.5′ in a NE-SW swathe of mixed magnitude stars in which a dozen mag 12-14 stars are resolved. The stars seem to circle around the western and southern sides of lovely nebulous and starry NGC 2048 which perches on the association’s northeast corner.

N154A = NGC 2048 (Emission Object)

RA 05 35 55.0 Dec -69 39 00 Mag 12.2 Size 2′

16″ at 228x: NGC 2048’s location is lovely, lying as it does cradled on its south and west sides by a large, semicircular chain of LH 87’s stars. Without a filter, NGC 2048 appears as a brightish glow among the stars, but it is the UHC filter that reveals its true nature: it appears as a beautifully bright glow, ~1′ x 0.8′ in size and elongated E-W. Its glow is rich and smooth, with crisp edges.