Archive for May 2016

M100 – NGC 4321 – Galaxy in Coma Berenices

May 21, 2016

Observer’s Challenge Link:  

MAY 2016 OBSERVERS CHALLENGE – M-100-1

M100 – NGC 4321 – Galaxy in Coma Berenices 

Date: April 2016
NELM: 5.0
Telescope: 10-inch Newtonian Reflector
Magnification: 57x
Field of View: 1.1º

Description: Low surface brightness, mostly round with a subtle NW-SE elongated halo. Bright nucleus, almost stellar at high magnification. A very dim patch W of the core and a hint of a spiral arm on the SW edge.    Roger Ivester

The following is a pencil sketch using only a No.2 pencil, an eraser, a blank 5 x 8 notecard with the colors inverted using a scanner.  RI 

Scanned Image 161410000

The following information and image provided by Dr. James Dire from Hawaii.

M100
By James Dire, Ph.D.

M100 is located in the constellation Coma Berenices. It lies 8 degrees east and slightly north of the star Denebola (Beta Leonis). It can be found roughly 40% of the way along a line from Denebola to the star Diadem (Alpha Comae Berenices). At magnitude 9.3, M100 is one of the brightest galaxies in the Coma-Virgo Cluster. M100 was first spied by Pierre Merchain in 1781 and then confirmed by Charles Messier later that year. M100 is a face-on spiral galaxy located 56 million light years away as determined by measuring the periods of Cepheid variable stars in the galaxy.

My image of M100 was taken with a 190mm f/5.3 Maksutov-Newtonian with an SBIG ST-2000XCM CCD camera. The expose was one hour. The galaxy has two main spiral arms with numerous branches. The arms contain many massive, hot, blue giant stars with many HII giant clouds of gas. The nucleus is bright and compact.

M100

The second image has labels for several nearby galaxies and their magnitudes. All are members of the Coma-Virgo cluster.

M100_legend

The following sketch and notes compliments of Jaakko Saloranta of Finland.

M100_2016_LVAS

Rough sketch made at the eyepiece. 8 inch dobson shows a bright galaxy with a nearly stellar nucleus @ 38x –(66′). Best visible @ 152x (16′) but the spiral structure is very difficult. Flanked nicely by two 14th magnitude stars. Bright, non-stellar nucleus surrounded by a E-W elongated halo. Northern spiral arm is brighter with a brighter spot at the W end. Southern spiral arm is slightly smaller but with two brighter areas visible in the arm in both ends. It takes over an hour to discern the spiral structure properly with this aperture. NGC 4323 and NGC 4328 not looked for.    Jaakko Saloranta 

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NGC 3077 – Galaxy – Ursa Major

May 3, 2016

Observer’s Challenge Link:  APRIL 2016 OBSERVERS CHALLENGE – NGC-3077

The following pencil sketch was made using a 10-inch reflector, and a  5 x 8 blank notecard with the colors inverted via scanner.  Roger Ivester

Scanned Image 161230001

NGC 3077 – Galaxy – Ursa Major
Date: April 25, 2016
NELM: 5.0
Telescope: 10-inch Newtonian reflector
Eyepiece: 12.5 mm + 2.8x Barlow
Magnification: 256x

At 57x, fairly easy to see, appearing mostly as a circular glow. At 91x, the galaxy becomes elongated with a NE-SW orientation, and a brighter central region, however, subtle. When increasing the magnification to 256x, a stellar nucleus is visible, but cannot be held constantly. The surface brightness of this galaxy is fairly low, making it difficult from my moderately light polluted backyard.

After viewing close neighboring galaxies, M81 and M82, which are much brighter and larger, NGC 3077 can be difficult, and maybe even a bit disappointing.

Roger Ivester

The following report and images are courtesy of Dr. James Dire of Hawaii.

NGC 3077
By Dr. James R. Dire

NGC3077 is a peculiar galaxy located in Ursa Major near the galaxy pair M81 and M82. The galaxy was discovered by William Herschel on November 8, 1801. Although the galaxy looks like an elliptical galaxy in the eyepiece, images of it show it has wispy edges and dark dust lanes, atypical of elliptical galaxies. Carl Seyfert included it in his list of active galaxies (now called Seyfert galaxies) in 1943. Today it is considered an irregular galaxy. Its distorted shape is probably casued by gravitational interactions with the large spiral galaxy M81, similar to Barnard’s Galaxy, NGC6822, which is equally close to the Milky Way.

Magnitude estimates for NGC3077 range from 9.9 to 10.8. The galaxy is 5.3′ x 4.4′ in size and is located 12.8 ± 0.7 Mly away. The galaxy is located three-quarters of a degree east-southeast of M81.

The first image was taken with a Stellarvue SV102 102 mm apochromatic refractor at f/6.3 using a Televue 0.8x FF/FR. The camera was a Canon 30D and the exposure was 60 minutes. In all images, north is up and east to the left. Image 1 was framed to have M81 and M82 centered. NGC3077 is labeled in the lower left-hand corner of the frame.

The second image was taken with a 10″ f/6 Newtonian with a Paracorr II coma corrector, yielding an f/6.9 optical system. A SBIG ST-2000XCM CCD camera was used. The exposure was 100 minutes. I really need 300-400 minutes of data to bring out the wispy edges and dark dust areas of the galaxy. But they can (barely) be seen in this short exposure. Unfortunately, time and weather did not allow more imaging before submitting this report.

Image 1

 

Image 3