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.
Comet 17P/Holmes
By Erika Rix
The comet was created with charcoal loaded onto a thick blending stump. I added some fine touches with a number 2 pencil for accuracy on the brightest areas. The stars were done with a number 2, .5mm and .3mm mechanical pencils.
Observation made with an Orion ED80 on an LXD75 mount, 21-7mm Zhumell eyepeice with diagonal.
Jupiter
Gas Giant Planet
By Eric Graff
Parks Astrolight EQ6 • 6″ f/6 Newtonian Reflector
7.5mm Parks Gold Series Plössl + 2x Barlow • 240x, 13′ FoV
1 October 2007 • 02:30-03:00 UT
By the 1st of October, Jupiter is slipping quickly into the evening twilight, so I was pleased to make this final observation of Jupiter for the 2007 opposition. The four Galilean satellites are arrayed as follows (preceding to following): Europa (forming a close pair with a 10th magnitude field star), and Io on the west side of the planet; to the east, bright Ganymede forms another close pair with slightly fainter Callisto. Another faint field star lies just beyond these two, masquerading as yet another Jovian satellite.
The cloud belts of Jupiter displayed a pleasing amount of detail. The north equatorial belt is considerably darker than the south equatorial belt, which is split in two by a bright lane. Conversely, the south polar region was more prominent than its southern counterpart. The equatorial region itself was quite bright with subtle indications of the festoon activity which has lately characterized the region.
Delta Geminorum
By Wade V. Corbei
This is an interesting double star (in all actuallity a Binary star) found in the constellation Gemini (as noted by the name). The Primary star is much larger than the companion star, and appears as a yellowish-white, while the companion appears as a nice contasting purple. Delta Geminorum also holds a historic significance as well, as in 1930 Clyde Tombaugh discovered the planet Pluto 1/2° east of this star.
A unique star with an equally interesting history.
Archimedes Crater
By Barry Chase
This drawing of Archimedes Crater is Barry Chase’s second Lunar sketch. The Lunar terminator’s close proximity provides strong, shadowed relief to the crater’s rim and surrounding terrain. Archimedes is 83 km in diameter, 2.1 km deep, and is the largest crater in Mare Imbrium. It does not possess a central peak, but does sport a 30 km long triangular promontory extending from its southeast rim.
Source: Wikipedia
Comet 8P/Tuttle
By Martin McKenna
Comet 8P/Tuttle will be making a noteworthy apparition over the next couple months, passing .25 AU from Earth on January 2nd. Although it could become visible to the naked eye for observers with dark skies, it is still rather faint. Martin McKenna made an early visual observation and sketch of the comet on the evening of November 14/15. Note that since the comet is sketched at an appropriately faint level, any incidental glare on your monitor may make it difficult to see.
Notes from Martin’s observation:
Last night (Nov 14/15th 2007) I made my first visual observation of 8P/Tuttle at 03.58 UT in an incredible sky between banks of thick fog. Tuttle was located in the high northern circumpolar sky below Polaris and not far to the SW of 4th magnitude Delta Ursae Minoris. Using the 8.5″ F/7 reflector with 32mm 1.25″ eyepiece I conducted a systematic search through this area without success as on previous nights. However I managed to catch the comet which surprised me after 45 minutes of fruitless searching. The comet was extremely faint and looked like a circular patch of green haze in a field of faint stars. Tuttle was extremely diffuse – difficult to tell where the coma ended and the sky began. At centre I could see a faint pin prick condensation. No tail observed. It was observed faintly with direct vision however averted vision was needed to see its full extent. I was delighted to finally catch Tuttle at such a faint magnitude and look forward to watching its rapid development. 17P/ Holmes and 8P/Tuttle where a real treat at this silent hour of the night. This is my 42nd observed comet.
Mag: + 10.9 – 11.0, Dia: 3′, D.C: 2
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.
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.
17P/Holmes
Periodic Comet
By Eric Graff
Parks Astrolight EQ6 • 6″ f/6 Newtonian Reflector
7.5mm Parks Gold Series Plössl • 120x, 26′ Field of View
26 October 2007 • 09:45-10:15 UT
On the 23-24th of October, 2007 Comet 17P/Holmes experienced a major outburst, increasing its brightness 1 million times in just a few short hours, rising from 17th to 2nd magnitude. Such events are usually caused by the sudden release of gas and/or dust particles from the comet (the yellow color suggests the latter, in this case). During the early morning hours of October 26, the smoke from the Southern California fires had cleared sufficiently to make this observation. To the unaided eye, 17P rivaled the brightest “star” in the constellation Perseus – appearing only slightly less prominent than magnitude 1.8 Alpha (α) Persei (Mirfak). In 10×50 binoculars it had a bright yellow hue and looked slightly fuzzy or unfocused.
Through the eyepiece of my telescope the golden hue was striking as was its brilliance, near-perfect circular symmetry, and sharp stellar pseudo-nucleus. It resembled a huge, bright, yellow planetary nebula about 4′ in diameter. At high magnifications (120x, 240x) the central regions of the comet displayed considerable detail. A bright arc of material extends from the nucleus from south to west, with three prominent streamers involved in and extending from this arc. The circular coma has a somewhat annular appearance. Beyond the bright circular coma, two faint plumes of material, one to the northwest (elongated) and the other to the south-southeast (very broad and diffuse) could be detected by gently rocking the scope from side to side.
This comet was discovered by British astronomer Edwin Holmes on November 6, 1892 while conducting observations of the Andromeda Galaxy (M31). The entirety of its 6.88 year orbit is spent between the orbits of Mars and Jupiter.
NGC 2169 – The 37 Cluster
By Wade V. Corbei
NGC 2169 is an open cluster located near the apex of Orion’s raised eastern arm. It has become known for an asterism of stars within it that appear form an angular representation of the number 37. NGC 2169 lies 3600 light years away and is receding at about 16 km/sec.*
*Source: SEDS
