Australian Sky & Telescope - June 2018

(Ron) #1
http://www.skyandtelescope.com.au 51

by Sue French TARGETS

117 × the annulus becomes distinctly
oval, with ends that are dimmer than
its sides. The ring’s interior isn’t as
dark as the sky, creating an overall
effect that John Herschel likened to
“gauze stretched over a hoop”. M57
bears magnification well and appears
quite stunning at 234×. Variations in
brightness along the rim are accented
at this higher power, and the ring’s
interior appears rounder than its outer
periphery, as shown in my sketch on the
next page.
Those who hunt more difficult
game can stalk M57’s 15th-magnitude
central star. Although folks have snared
itthroughscopesassmallas 20 cm
in aperture, I’ve never nabbed it with
anything smaller than my 36.8-cm.
Thekeytoasuccessfulsighting lies
in having exceptionally good seeing

Winter deep sky delights


Warm nights and dark skies are ideal for enjoying these classic beauties.


A


top our grassy hill, green fields
turn obsidian as night sweeps
her cloak across the world. A
telescope is waiting, the stars appear,
and I’m where I belong. Winter nights
are an ideal time for those of us who
feel at home among the stars to lose
ourselves in some of the most beautiful
wonders of the deep sky.
Planetary nebulae are shining baubles
on the dome of the sky that come in
an amazing wealth of guises. One of
the most famous is the Ring Nebula
(M57) in Lyra, which Antoine Darquier
independently discovered with a small

refractor while observing the Comet of


  1. He claimed it resembles a planet
    that’s fading away. Although Darquier
    may have been the first to compare
    this type of nebula to a planet, it was
    William Herschel who coined the term
    ‘planetary nebula’ several years later.
    M57 is low in the north for most
    Australasian observers, but it’s worth
    giving it a try to see this well-known
    bauble. My 130-mm refractor at 23×
    clearly shows M57 as a very small
    nebula bracketed by the stars Beta (β)
    and Gamma (γ) Lyrae. Its ring-like
    structure reveals itself at just 37×. At


ESO / S. GUISARD


TBright nebulae and brilliant star clusters sparkle along the dark dust lanes of the Milky Way
Galaxy. Taken from Cerro Paranal, Chile, the image below, which shows the winter Milky Way
between Sagittarius and Scorpius, was assembled from 52 different sky ields composed from
about 1,200 individual images taken through B, V, and R ilters with a 100-mm refractor. The inal
mosaic represents a total of 200 hours exposure time.

Rho Ophiuichi

Milky Way Galaxy

Lagoon Nebula

M21
Triid Nebula

3 Sgr

M7

Butterly
Cluster

NGC 6357

NGC 6334
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