Nebulae – Page 46 – Astronomy Sketch of the Day

Tenuous Apparition

NGC 896
By Rony De Laet

Hello sketchers,

Last week, my family and I were on vacation in Bischofshofen, Austria. I managed to bring my little Skywatcher along. The weather was great. Three nights were clear! With multiple layers of clothing, I withstood the freezing cold for about 90 minutes each evening. Here is an observation of a portion of the large nebulosity cataloged as IC 1848 and IC 1805 : NGC 896. Sue French described this object as small and bright. I found NGC 896 rather faint in my scope. An UHC filter plus wiggling the scope helped to bring out some detail. Here is the sketch.

Date : December 29, 2007
Time : around 17.30UT
Scope : Skywatcher 102/500
Vixen LV Zoom at 14mm
Power : x36
FOV: 85′
Filter : Lumicon UHC
Seeing : 3/5
Nelm : 5.7
Temp : -6°C
Elevation : 800m ASL

Sketch Orientation : N up, W right.
Digital sketch made with PhotoPaint, based on a raw pencil sketch.

Shock Value

The Veil Nebula West
By Rob Esson

10B graphite pencil with blending stump on white sketch paper. Digitally inverted.
8in LX200 f/6.3 with 31mm Nagler and UHC filter. Field of view 1.88deg, 41x
magnification. Drawn Sept 7, 2002 at the late lamented Great Plains Star Party under
excellent transparent skies and steady seeing.

The Veil Nebula West (NGC6960, Caldwell 34) is a supernova remnant which seems too
delicate to the eye to really be a shock wave from the blast crashing into the
interstellar medium!

One Wild and Distant Duck

The Wild Duck Cluster, M11
By Jeremy Perez

M11 holds a special place for me. It was the first deep space object I viewed through the new telescope–besides M45 & M31 which I had seen before. It was very exciting to see something with my own eyes that prior to that night I never even knew existed. It was a symbol for me of what else lies in the sky that I don’t yet know about. Beautiful. A striking collection of stars. I revisited it this night under less than perfect conditions. It was diving into some of the worst light pollution from my home vantage point. Oh, and the moon was starting to rise. It demonstrated dense and mottled granularity, with numerous resolvable stars winking in and out across the surface. (Did I mention seeing was really bad too? 3/10. Right.) Anyway, one bright star dominates the center of the cluster, and 2 others close stars reside just outside to the SSE. (It should be noted that these bright stars are actually foreground stars, and aren’t part of the cluster.) The overall shape of the cluster is circular with a central cloud surrounded by a gap, and then a rough ring of stars. OK. I know I’ve said this before, but once more for emphasis: to me, the “Wild Duck” name doesn’t just look like a V-shaped ‘flock of ducks’, but actually looks like a duck raising it’s wings to take to flight, with the head at the SW side of the central concentration of stars, and the wings curling around on the NW and SE sides. The dimension of the main body of the cluster appeared to be 7′ across.

Factoids:
M11 is one of the richest and most compact of the open clusters. It is 6,000 light years away, and contains around 2,900 stars. If our planet were in the midst of this cluster, we would see several hundred brilliant first magnitude stars scattered across the night sky. Amateur astronomy would probably be pretty tough in a sky so brightly lit at all times. M11 was discovered in 1681 by Gottfried Kirch, first resolved into stars in 1733 by William Derham, and then included in Charles Messiers catalog in 1764. Its age is currently estimated to be 250 million years, and it is receding from us at 22 km/sec.

“Like M42 on steroids!”

The Eta Carina Nebula
By Rob Esson

10B Graphite pencil on white sketch paper with blending stump. 18in f/4.5 Obsession
Dob with 17mm Nagler, giving a 0.7 degree field of view and magnification of 121x.
Sketched at the Deepest South Texas Star Party held at the Warrumbungles Mountain
Lodge in New South Wales, Australia on March 22, 2007.

I thought that I would follow up Jeremy Perez’ drawing of the Eta Carinae region
with binoculars (11/29/07) with a more detailed telescopic view. The Eta Carinae
region of nebulosity goes on – seemingly – for ever. This is merely a sketch around
the middle, and due to clouds coming in, is not as detailed as I might have liked if
I had had more time. The ‘blob’ about 2/3rds of the way towards about 12:30 on the
sketch is the Eta Carinae homunculus. Words are difficult to find to describe this
sight: it is probably the most impressive area in the sky. Although this sketch was
made using a Dob, binoculars or a wide field telescope are needed to take in the
nebula in its entirety. The Hubble pictures are no doubt fun to look at with all
their false colors, but the visual effect through the telescope, when the photons
are extinguishing on your own retinas as opposed to a ccd, is one of absolute
wonder: there are just numerous areas crying out to be examined in detail, like M42
on steroids!

Rob Esson, Kansas City MO

Elusive Continent

NGC 7000 – The North America Nebula
By Rony De Laet

How many summer nights have I been looking to find this great nebula? I’ve tried with a 10cm f10 newton, a 20cm f10 dobson, an ETX 105 f14. But no result. This year I was armed with a widefield low budget SkyWatcher plus a 32mm Televue eyepiece and a Lumicon UHC filter. And there it was, a distinct glow with the shape of a continent! How beautiful, and finally I saw it in my sky. Here is the sketch. I also tried to render the effect of the UHC filter on brighter stars. Somehow this filter produces large halo’s around the brighter stars.

Date : September 15, 2007
Time : 21.30UT
Scope : Skywatcher 102/500
TV Plössl 32mm
Power : x16
FOV: 150′
Filter : Lumicon UHC
Seeing : 3.5/5
Transp. : 3/5
Nelm : 5.2
Sketch Orientation : N up, W right.
Digital sketch made with PhotoPaint, based on a raw pencil sketch.

Note:
Rony De Laet discusses his sketching method here: About the Drawings
His gallery can be found here: My EXT-105 Project

Eta Carinae from Haleakala

Eta Carinae Complex and NGC 3293
By Jeremy Perez

Move mouse over image to see labels. Click for larger image.

The observing highlight of an evening atop the summit of Haleakala in Maui was gazing through my binoculars at the rich starscape in the vicinity of Eta Carinae. I had not done any homework on the area beforehand, so I approached it with unexpecting eyes. The mottled depths of the surrounding Milky Way, the smattering of intensely bright foreground stars, the abundance of open clusters of all shapes, sizes and intensities, and the stunning patches of glowing nebulosity made the whole region a delicious feast for the eyes. One incredible open cluster to the northeast, nearly took my breath away, but I did not have time to even attempt a sketch of it. Instead, I chose to render the region bracketed by the Eta Carinae complex and a much more manageable cluster, NGC 3293.

Eta Carinae was a brilliant orange star that surrounded itself in a plush comfort of nebulosity. This misty region ended abruptly to the south and then emerged again to surround a trio of bright stars. The observation and sketch were done more hastily than I would have liked and I know there was more detail to be extracted from this bright nebula, but I took what I could get. The northwest side of the view was punctuated by the small, bright open cluster, NGC 3293. Four bright stars announced themselves within its glowing boundary of unresolved starlight.

This section of the sky is still beckoning me, and I know I will have to return to it again with more time to spare. Even if I only have binoculars again the next time, it will still offer more than I can possibly absorb.

The sketch was created on Strathmore sketch paper with 2H and HB pencils. Nebulosity was shaded with a blending stump loaded with graphite. Color was added to Eta Carina in Photoshop.

Object Information

Eta Carinae is one of the most massive stars in the universe and is likely greater than 100 solar masses. It is about 4 million times more luminous than the sun, but radiates 99% of this energy in the infrared. Due to its extreme mass, it is expected to go supernova within the next few hundred thousand years. In the meantime, as it rapidly sheds matter, it goes through sporadic, violent outbursts. The most recent outburst peaked in 1843 when Eta Carinae became a magnitude -1 star, second only to Sirius. This eruption generated a rapidly expanding plume of gas that now forms a fascinating dumbell shape.

A Spiral That’s Not a Galaxy

NGC 5189
By Eiji Kato

NGC 5189 is an unusual planetary nebula located an estimated 3000 light years away in star-rich region of the constellation Musca. It is sometimes referred to as the “Spiral Planetary” and gets its unusual shape from our edge-on perspective.

An in-depth discussion of this fascinating celestial object can be found in this article by Andrew James.

More of Eiji Kato’s deep sky and comet sketches can be found in his gallery.

Arm of the Eastern Veil

Eastern Veil Nebula – NGC 6992 and NGC 6995
By Kiminori Ikebe

Lying some 1400 light years away in the constellation Cygnus is the beautiful supernova remnant known as the Veil Nebula or Cygnus Loop. When the supernova first lit up the sky thousands of years ago, it likely shone with the brilliance of a crescent moon (magnitude -8). The eastern portion of this broken circle of nebulosity is catalogued as NGC 6992 and NGC 6995. The full area of the Veil Nebula spans more than 3 degrees of the sky. In order to capture much of the eastern arm, Mr. Ikebe broke it down into the two sketches shown above.

(Source: APOD}

Mr. Ikebe’s notes about this nebula:

A magnificent view. The nebulosity in the shape of an arch in which bright and dark areas entwine in a complex manner. It is not possible to describe in words. It is difficult to draw it accurately and this sketch only shows how this nebula is perceived. The Veil Nebula is one of the most complex but clearest objects in the northern sky. The nebulosity from NGC 6992 to NGC 6995 is the brightest part of the Veil Nebula and even 10×42 binoculars reveal an arch-shaped nebulosity clearly.

(Re: NGC 6995) The complex area on the southern end of the arch in the east. The tip of the nebulosity divides into several branches looking like a human hand trying to grasp something. Off the tips of the fingers there are two faint areas, which may be IC 1340.

Equipment used: 32 cm Dobsonian at 70X
Sketch Media: Black paper, white paint (for stars), white watercolor pencil, and tissue paper. A Japanese language discussion of Mr. Ikebe’s sketching technique with photos can be found here: How to Make a Sketch. Translating the page using Google Language Tools can help with some of the text.

Messier’s Swan

M17 – The Swan Nebula
By Jeremy Perez

Observation Notes:
From Anderson Mesa, this nebula appears much larger than the typical swan shape that I see from home. The back of the swan is the brightest portion with the neck second brightest. The head appears to have a crest, and fainter wings appear above the body. The tail flows out to the southeast and then in multiple flowing arcs to the northeast and back around to the northwest.

I chose the 25 mm Plössl eyepiece to capture the full extent of nebulosity in its 66 arc minute true field of view. There was a bright yellow-orange star to the northwest of the nebula as shown in the image. This sketch took 2 hours to complete, but the sky was clear and the experience was enjoyable. My only concern was that it would sink too far into the murk in the southwest before I finished. 172 stars are plotted in the sketch.

I used 2H and HB graphite leads to plot the stars, and a blending stump loaded with graphite to shade in the nebula. After scanning and inverting the sketch I used a soft, mostly transparent brush to add a bit of glare around the brighter stars and added color to the yellow-orange star on the northwest side of the view.

Object Information*:
M17 is a region of star formation that shines by excited emission of light from radiant young stars within. The stars that heat and illuminate this nebula aren’t readily visible, but are hidden within. It is estimated that a small cluster of about 35 of these stars are imbedded in the nebulosity.

Photographically, the color of the Swan Nebula is reddish. This color comes from the hot hydrogen gas excited to shine by the hottest stars which have just formed within the nebula. However, the brightest region is actually a white color. This white color isn’t just a photographic overexposure as I had thought, but is apparently a result of a mixture of red emission light, together with reflections of the bright star light from the dust in that region. The nebula also contains a large amount of dark obscuring dust, which is responsible for giving it its distinctive shape. However, even this dark dust is glowing brightly in the infrared spectrum, heated by hidden young stars.

The bright portion of the nebula extends roughly 15 light years, but the total cloud seems to extend at least 40 light years. The amount of matter in the cloud is estimated at about 800 times that of the Sun, which makes it more massive than the fantastic Orion Nebula (M42). It’s estimated that M17 is 5,000 to 6,000 light years away. It was discovered by Philippe Loys de Chéseaux in 1745-46, but wasn’t widely known, and so rediscovered by Charles Messier in 1764. Under very favorable conditions, M17 is just visible to the naked eye.

This object is known by a number of common names: Swan, Checkmark, Horseshoe, Omega. It is also catalogued as: Cr 377, Lund 827, LBN 60, Sh2-45, h 2008, GC 4403, OCL 44.

*Source: SEDS; ngcic.org

The Water Bearer’s Spiral

NGC 7293 – The Helix Nebula
By Eiji Kato

The Helix Nebula lies roughly 450 light years away, making it one of the closest planetary nebulae (distance estimates range from 85 to 590 light years). With a diameter of 16′ for the main portion of the nebula and an outer halo diameter of 28′ its apparent size is among the largest known planetary nebulae. Although the nebula is intrinsically bright, its large size makes it a difficult target for visual observation under less than ideal sky conditions. It was discovered by Karl Ludwig Harding before 1824.

More of Eiji’s deep sky and comet sketches can be found in his gallery.