|
Veil Nebula - TSA102S
Veil Nebula
|
The Veil Nebula, also known as the
Cygnus Loop or the Witch's Broom Nebula, is a
large, relatively faint supernova remnant in the
constellation Cygnus. The source supernova
exploded some 5,000 to 8,000 years ago, and the
remnants have since expanded to cover an area of 3
degrees; about 6 times the size of a full moon.
The distance to the nebula is not precisely known,
with estimates ranging from 1,400 to 2,600
light-years. It was discovered on 1784 September 5
by William Herschel. He described the western end
of the nebula as "Extended; passes thro' 52 Cygni...
near 2 degree in length." and described the
eastern end as "Branching nebulosity... The
following part divides into several streams
uniting again towards the south."
When finely resolved, some parts
of the image appear to be rope like filaments. The
standard explanation is that the shock waves are
so thin, less than one part in 50,000 of the
radius[1], that the shell is only visible when
viewed exactly edge-on, giving the shell the
appearance of a filament. Undulations in the
surface of the shell lead to multiple filamentary
images, which appear to be intertwined.
The nebula is notorious among
astronomers for being difficult to see visually,
even though it has a bright integrated magnitude
of 7. However, a telescope using an OIII filter (a
filter isolating the wavelength of light from
doubly ionized oxygen), will allow an observer to
see the nebula clearly, as almost all light from
this nebula is emitted at this wavelength. Using
an 8-inch (200 mm) telescope equipped with an OIII
filter, one could easily see the delicate lacework
apparent in photographs. With an OIII filter,
almost any telescope could conceivably see this
nebula, and some argue that it can be seen without
any optical aid, excepting an OIII filter held up
to the eye. This is also one of the largest,
brightest features in the x-ray sky.
The brighter segments of the
nebula are listed in the New General Catalog under
the designations NGC 6960, 6979, 6992, and 6995.
The easiest segment to find is 6960, which runs
through the naked eye star 52 Cygni. NGC 6979 -
the central portion of the Veil Complex is
Pickering's Wedge, or Pickering's Triangular Wisp.
This segment of nebulosity was discovered
photographically by Williamina Fleming, but credit
went to her supervisor Edward Pickering, as was
the custom of the day, thus named after Pickering
as a result.
(From Wikipedia, the free encyclopaedia)
|
Exposure Data
 | Instrument: Takahashi TSA102S (TOA Reducer/
Flattener) |
| F/stop: 8 |
| Exposure: |
| Camera: Hutech Canon EOS 40D DSLR |
| Sensitivity: ISO 1600 |
| Date: August 28, 2008 |
| Exposure start: |
| Location: Albury, New South Wales |
| Autoguider: None |
| Enhancement: Registar 1.0, Adobe Photoshop CS2,
|
| Notes: Piggy backed on LX200 8" GPS, using
Meade Field de-rotator |
|
|
Public Viewing
Nights |
|
Just to let
everyone know, public viewing nights are held
every first Friday of the month. Clear or cloudy
nights the public viewing night goes ahead.
Members man a number of telescopes of various
sizes and types, and for those nights where the
sky is cloudy, extended astronomical presentations
are presented in the MPAS Viewing Centre.
So please come
along and enjoy our nights sky.
How to
get Here
(Click Here)
In 2011 MPAS
will host VASTROC.
For more information, click
here...
Where are
visitors seeking from..
|
|
