Category: Galaxy

The Whirlpool Welcomes a New Visitor

Object Name : M51, SN2011DH
Object Type : Face-on Galaxy, Supernova
Location : South Korea
Date : June 5th, 2011
Telescope : 15inch Discovery Dobsonian
Media : Black paper, White conte, White pastel

Nightwid (Cho Kang Uk)

Hi all, Supernova SN2011DH was easy to observing.
And I saw beautiful arms and bridge.. Because seeing is very good!

The Hockey Stick

The Hockey Stick NGC 4656

Sketch and Details by Serge Vieillard

Winter-Spring of 2011….extraordinary adventure at the base of Mount Chiran in the hinterland of Nice, France in early March, this was an astronomy meeting with the first light of a new 1000mm telescope belonging to David and an optical instrument of extraordinary and perfect mechanics. Each object pointed at was a high quality target screaming for joy. The big stars are revealed as never before, with a wealth of detail worthy of photos. It is illusionary to want to make an accurate drawing in those moments of intense emotions. It can only be evocations. The Canes Venatici galaxy leaves no one indifferent and one could stay in the eye to the end of the night to contemplate. The most reasonable galaxies reveal an unsuspected wealth, as here with the end of the troubled hockey stick, a form that evokes a kind of giant shrimp. While waiting my turn at the eyepiece, I take David’s 600mm scope and examine other interesting really targets.

Object: NGC 4656 Galaxy in Canes Venatici – Artist: Serge Vieillard – Sketch Date: Early March 2011

Supernovae in the Whirlpool

Object Name: 2011dh
Object Type: supernova
Location: Cherry Springs, Pennsylvania
Date: June 5, 2011
Media: digital

Notes

High absolute humidity made the dust lane detail in the western arm invisible, and the dust lanes in the outer arm to the south and east required special positioning of the eye. In this respect, the view was much worse than last time I observed M51 this spring. All details in the arms also looked “fatter.” On the other hand, the view this time was consistent throughout the night, and with the supernova (marked on the sketch) it was well worth staring at.

Earlier last week, when the supernova was already there but not yet broadly announced, and not yet known to me or my fellow observers, some gentlemen on the field suggested that I should look at M51, because it was so nicely positioned. I did not heed their advice, thinking that with the summer humidity, it would be hard to surpass the view I had earlier this year, and absorbed myself with some new objects. I had my earlier sketch with me in my journal (the rough ball-pen original), in which the superimposed stars were marked way below the magnitude of the supernova. It would be fun to make the discovery at least for myself if not for real, but even that apparently was not fated.

Magnitude 13.4 and Rising

Object names: SN2011by, NGC 3972, NGC 3977
Object types: supernova, galaxy, galaxy pair
Location: Cherry Springs Dark Sky Park, Pennsylvania
Date: May 5, 2011
Media: digital

Notes
16” Dobsonian, 75-300x. The supernova SN2011by is the brightest star in the field. It is superimposed on the NE edge of the elongated galaxy NGC 3972, just to the left of the galaxy’s core in the drawing. The round galaxy is NGC 3977, in which recorded supernovae occurred in 1946 and 2006.

As of this writing, supernova 2011by is still the brightest currently in the sky, and still rising at magnitude 12.5. The magnitude in the sketch title refers to the time of my observation. It is in NGC 3972 right next to Gamma Ursae Majoris. This is very nice intermediate-inclination spiral that I saw last year with my 4”. I still retain the mental image of a nicely elongated blob. It can now serve me as something that supernova photographers would call the “pre-discovery image.” SN2011by was discovered at the end of April. At the redshift distance of NGC 3972 (46 Mly) it should become mag. 11.5, according to my rough calculations, and at the mean Tully-Fisher distance from NED (18 Mpc) it should still become 12.0. I.e. it might become a worthy target for “department-store scopes.”

I was curious about the structure in the host galaxy, which is featured in The de Vaucouleurs Atlas as a paradigmatic SA(s)bc. The southwest edge, which is opposite the supernova, is the one closest to us, judging by the photos. I thought that with some appropriate effort expended, the arm running along this edge and even some enhancements in it could potentially be visible in a 16”. But, somewhat disappointingly, all I could see was this edge being sharper than the one with the supernova. The view was essentially identical under a range of magnifications from 100 to 300x. On the other hand, this means that my “post-discovery image” (the view through the 16″) is only subtly different from my “pre-discovery image” (last year’s view throught the 4″), as far as the galaxy itself is concerned.

The field overall is very impressive. Not to mention the supernova, the elongation and asymmetry of NGC 3972 have their counterpoint in the perfect roundness of its apparent companion, NGC 3977. Unlike NGC 3972, this face-on spiral could not be just casually swept up last year with the 4”, and I did not stop to look for it then. NGC 3977 itself was host to two recorded supernovae, 1946A and 2006gs. About them I can only find that 2006gs reached mag 17. The only distance for NGC 3977 in NED is by redshift, 263 Mly. This is far indeed – 5 times farther than NGC 3972, adding to the perceived depth of this remarkable field.

At the eyepiece, I make a schematic in ball pen that records the essential information about positions, sizes, and the contrast, and concentrate on preserving my dark adaptation and building the mental image instead of detailed sketching. Subsequently I use a pressure- and tilt-sensitive digital pen tablet to simulate pencil, blender, and other traditional tools, to create the clean digital drawing, concentrating on conveying the visual appearance of stars and nebulosity.

Well Tuned Antennae

Object Name: NGC 4038/9
Also Known As: H.IV.28, Arp 244, the Antennae, Ring Tail Galaxies
Object Type: Interacting Galaxy Pair
Constellation: Corvus
Right Ascension (2000.0): 12h 01m 53.2s
Declination (2000.0): –18° 52′ 38″
Magnitude: 10.7
Dimensions: 4.5′ x 3.6′
Hubble Class: S?/pec
Distance: 63 million light years
Discovery: William Herschel on 7 February 1785 with 18.7-inch reflector
NGC Description: 4038 – pB, cL, R, vgbM; 4039 – pF, pL

Telescope: Parks Astrolight EQ6 • 6″ f/6 Newtonian Reflector
Eyepiece/Magnification: 7.5mm Parks Gold Series Plössl • 120x • 26′ Field of View
Filter: None
Date/Time: 30 April 2011 • 04:15-05:00 UT
Observing Location: Oakzanita Springs, Descanso, San Diego Co., California, USA
Transparency: NELM 6.2; TLM 14.2
Seeing: Pickering 7-8
Conditions: Clear, calm, cold, humid

This interacting galaxy pair is best located about 50 arc minutes NNE of the fifth magnitude star HD 104337, the brightest star on the western border of Corvus. While you are in the area you might do well to look for NGC 4027 30′ NW of HD 104337 and NGC 3981 68′ WSW of that star. The Antennae would be a challenging target for binocular observers.

At 30x magnification, this galaxy pair appears as a soft asymmetric patch of nebulosity, larger and brighter toward the north, smaller and fainter toward the south, but with no other details readily visible. Another soft, featureless patch of nebulosity may be glimpsed in the same field of view, 42′ away to the SW; this is NGC 4027, an 11th magnitude barred spiral galaxy and a fine target in its own right.

At 60x magnification, the Antennae or Ringtail galaxies are clearly resolved as two separate (though attached) objects. Together they look like a lopsided heart or a bloated “V”, with occasional glimpses of mottling across the face of the nebulosity. At 120x magnification the western rim (shaped like a backward “S”) of the pair is clearly brighter and more distinct than the rest of the object. During moments of good seeing this bright rim breaks into several distinct knots. The central region of NGC 4038 appears almost hollow by comparison; perhaps this is why Herschel catalogued this object as a planetary nebula. Averted vision revealed occasional glimpses of the base of the southern tail.

At 120x magnification NGC 4038 and NGC 4039 share the 26′ field of view with 9th-magnitude TYC 6097-326-1, white, about 6.5′ NW, 10th-magnitude TYC 6097-415-1, orange-red, about 9.5′ S, 11th-magnitude TYC 6097-619-1, yellow-white, about 10.8′ NE, 11th-magnitude TYC 6097-288-1, yellow-orange, about 13′ NNW, and 11th-magnitude TYC 6097-629-1, yellow, about 12.5′ NW. The remaining field stars are in the 12-14 magnitude range.

The sketch presented here depicts the view at high magnification (120x). The sketch has been rotated so that north is up and west is to the right. The sketch was executed with a No. 2 mechanical pencil with 0.5 mm lead, and two blending stumps (8948B, 8941B) on 100 lb. white card stock. The original drawing measures 7½ inches across.

This observation was made from a reasonably dark site (borderline blue-green on LP maps) at an elevation above 4,000 feet. The NELM was estimated at 6.2, the TLM at 14.2 in the vicinity of the target. The seeing conditions were above average (Pickering 7-8), but the humidity was quite high and care had to be taken to prevent dew from accumulating on optics and sketching materials. The temperature was 37°F. The air was very still and the high magnification views very steady.

The Misplaced Core

Object name: NGC 4013 (galaxy in UMa)
Location: Nádasdladány, Hungary
Date: May 2, 2011
Media: B pencil on white paper, then inverted on computer
SQM reading: 21.23m/arcsec^2, 5°C
Weather: we had rains all day yesterday, so the air has a very high humidity now

I was very surprised when I noticed that this galaxy has its core out
of its geometrical center. I was wondering if this is the result of a
single, well grown spiral arm, but later studies revealed the answer
for this phenomenon: the misplaced core is actually not at all related
to this tiny edge-on galaxy but it’s only a foreground star in our own
Milky Way. This little gem is located in a very sparse stellar
environment which makes it a difficult target.

Ferenc

Connecting the Two Galaxies

Object Name (M51)
Object Type (Galaxy)
Naxxar, Malta
April 2nd, 2011 @ 22:38UT
Graphite pencil, charcoal, blenders, white paper, scanned and inverted using GIMP)

M51 under averted vision.
200mm SCT, f/10, 25mm, eyepiece, 81x, binoviewer, light pollution filter.

On April 2nd, 2011 I spent an hour observing this magnificent Messier object. I have produced the sketch using graphite pencils and blenders on white paper, scanned and inverted the digital image using GIMP. It is based on the intensity sketch shown below drawn at the eyepiece under averted vision.

I wanted to portray the ‘ghostly’ appearence of the two galaxies to mimic the actual eyepiece view. Most of the observing time was spent detecting under averted vision the very faint streak that connects the two galaxies as well as the spiral arms.