Roger Ivester: Amateur Astronomer

Posted December 15, 2015 by rogerivester
Categories: Uncategorized

Thank you for visiting my site.  I’m hopeful that you’ll find it both interesting and beneficial in your future observations.  Roger Ivester 

DSCF5178

 

M92 Globular Cluster in Hercules and “Trouvelot’s Hook”

Posted August 1, 2016 by rogerivester
Categories: Observer's Challenge Reports

The Observer’s Challenge complete report:  JULY 2016 OBSERVERS CHALLENGE – M-092

The following write-up and sketch by Jaakko Saloranta of Finland, one of the most talented and gifted visual observer’s in the world today.  Roger Ivester 

Messier 92

The baby brother of Messier 13. Brightest star in the cluster is magnitude 12.1 so it is fairly easy object to resolve. However, it is a difficult naked eye object: barely visible with optimal averted vision at an altitude of 57 degrees. Easily visible with a 8×30 binoculars as a non-stellar smudge.

Forms a triangle with two 10th magnitude stars. Partial resolution is achieved – only a handful of stars visible – with a 3 inch refractor @ 133x (23′). With a 4.5 inch SkyQuest XT @ 152x (20′) M92 appears as fairly well resolved, with a few dozen stars visible. Bright core, might appear slightly elliptical but is probably just an illusion caused by unresolved stars NW of the nucleus.

Messier 92 contains a little known small feature nicknamed “Trouvelot’s Hook” (named after 19th century French astronomer Étienne Léopold Trouvelot) . It is a hook-shaped chain of stars with dark bays at both sides. The feature is visible in two separate sketches made by Trouvelot. The first one is from 1874 and the second from 1877. Both sketches of M92 are made from Harvard College Observatory.

Having seen Roger Ivester’s notes on M92, it is obvious that Roger has noted – at least a part of – “Trouvelot’s hook”. He described it as “a faint chain of four stars follows the flattened edge”. This is part of the very same chain sketched by Trouvelot! I personally could not make out the dark lane sketched by Roger. I only saw a couple of bright stars just E of the cluster’s core.

Pencil Sketch By Jaakko Saloranta of Finland:

M92_2015_LVAS_1

The following sketches by French Astronomer, Trouvel0t. The first one was made in 1874 and the second 1877, both from the Harvard College Observatory.

M92_Trouvelot

Below:  Sketch by Trouvelot in 1877

DSC_0659

 

The following information and pencil sketch by the writer.  RI 

M92 – NGC 6341 – Globular Cluster in Hercules:  Date: May 27, 2016

Telescope: 10-inch f/4.5 Equatorial Reflector

Eyepiece: 11 mm – Also Other Observations With The Employ Of a 2.0x Barlow
Magnifications: 104x and 208x intermittently

Bright with an intense round core and a granular texture at 104x. When increasing the magnification to 208x, excellent resolution of stars in the outer regions and in the halo, with many outliers.

The overall shape has a subtle N-S elongation. The NNE-WSW edge is flat, which is one of the more noticeable and recognizable features of the cluster. When using averted vision a faint chain of four stars follows the flattened edge. These stars were not visible on two of the three nights of observations, and appeared intermittent or not constant.

The following is a pencil sketch using a 5 x 8 blank notecard, with the colors inverted using a scanner.  Please note the faint star chain on the eastern side of the cluster, on both my sketch and Jim Dire’s image.  It was extremely difficult for me, requiring averted vision, and could only see intermittently on the third night of observations.

Roger Ivester 

Scanned Image 162110000

M92:  The following image and text by James Dire of Hawaii

M92

James Dire, Ph.D.

M92 is the middle in size and brightness of three globular cluster located in the constellation Hercules. The brightest and largest is M13 while the smallest in our sky is NGC6229. All three globular clusters can be spied with an 8-inch or larger telescope.

Globular clusters are highly compact groupings of tens of thousands to millions of stars. There are approximately 150 of these clusters forming a spherical halo around our Milky Way galaxy. Globular clusters are also known to exist in other galaxies. The Andromeda galaxy probably has 2-3 times as many as the Milky Way.

M13 is the brightest globular cluster visible in the northern hemisphere and the third brightest visible from Earth. At magnitude 5.8, has a diameter of 25 arc minutes, nearly as large as the Moon. In comparison, at magnitude 6.4 M92 is roughly half as bright. It spans 15 arc minutes. Although both appear in Charles Messier’s famous catalog, he did not discover either of them. Edmond Halley discovered M13 in the year 1715 and Johann Bode discovered M92 in 1777.

M92 is found six and one-third degrees north of Pi Herculis, the northeastern-most star in the Keystone. Like M13, M92 can easily be spied in 50mm binoculars or finder scopes. Many stars can be resolved in both clusters using telescopes. Larger apertures will reveal more individual stars. I recommend eyepieces that yield 100x, or higher if the seeing is steady.

At magnitude 9.4, NGC6229 is quite a bit more challenging to find than M92. NGC6229 is located just north of the center of Hercules’ club, or 11 degrees north of M13. The easiest way to find it is to center the 5th magnitude star 42 Herculis in the eyepiece and hop two degrees to the southeast. William Herschel discovered NGC6229 in 1787. He was also the first to resolve stars in M92 six years later.

My image of M92 was taken with a 10-inch f/6 Newtonian with a Paracorr II coma corrector yielding a 1753mm focal length. The scope was atop a Paramount ME German equatorial mount and the image was taken with an SBIG ST-2000XCM CCD camera. The exposure was 20 minutes. The brightest star in the field of view, left (east) of the cluster, is HD156821 shining at magnitude 9.76. The faint star to the left of this is a 16.1 magnitude star. The yellow orange star on the northeast side of the cluster is HD156873, magnitude 9.98. The third brightest star in the field, to the lower right of the cluster shines at magnitude 10.9. None of these stars are members of M92.   James Dire 

Moon Day by James Mullaney

Posted July 23, 2016 by rogerivester
Categories: Uncategorized

Something I wanted to share by my good friend of many years, James Mullaney.  James is an astronomy writer, author, lecturer, former associate editor at both Astronomy and Sky & Telescope Magazines.  I sent James (Jim) a hand written letter almost twenty five years ago, praising him for his reference book “The Finest Deep-Sky Objects” and we’ve corresponded and been friends every since.  I’m really glad that I wrote that letter….sent via USPS with a stamp.   Roger Ivester 

Happy Moon Day! by James Mullaney  arcturussj <arcturussj@aol.com>: Jul 19 03:15PM -0400

Hi Everyone,

As I do just about every year at this time, I’m pushing for a national or international holiday to celebrate this momentous historic event. If there’s a Columbus Day on the calendar, surely there should be a Moon Day every July 20th. Still amazes me how many people have no clue what that date is (or October 4th, the beginning of the Space Age). Take a poll of your typical planetarium audience to see for yourself. But then just as shocking is how many people don’t know who Carl Sagan was. How very sad and shameful on all accounts.

Jim Mullaney, FRAS

M5 Globular Cluster in Serpens and The Mystery of The Ruby Eyes

Posted June 26, 2016 by rogerivester
Categories: Observer's Challenge Reports

Globular Cluster M5 and the Ruby Eyes.   Be sure to click on the following link for the complete report….

JUNE 2016 OBSERVERS CHALLENGE – M-005

10-inch reflector @ 208x:   Pencil sketch using a blank 5 x 8 blank notecard with the colors inverted via a scanner.  Note the dark lane on the northern edge, and the chain of stars on the  leading of the SSW  edge of the cluster.  RI Scanned Image 161780000

The following image was made using a 4-inch refractor by Dr. James Dire of Hawaii.  Please note the dark lane on the northern edge as shown in the previous pencil sketch.   

M5_4inch

The following Image by James Dire using a 10-inch reflector….again note the northern dark lane, and the chain of stars extending SSW away from the cluster, as shown in both images.

M5_10inch

 

Visual notes as following by the writer.  RI

M5 – NGC 5904 – Globular cluster in Serpens – Observer: Roger IvesterDate: May 27, 2016
Telescope: 10-inch f/4.5 Reflector
Magnification: 208x
FOV: 0.39º NELM: 5.0

Very bright, easily seen through an 8 x 50 finder. At magnitude 5.7, the cluster should be visible naked eye from a dark site. Well concentrated and dense in the central region, with many stars resolved at 208x. When using averted vision, a chain of stars encompasses the northern edge, creating a subtle void between this chain and the main cluster. Also with averted vision, a very faint chain of stars lead off toward the SW. A halo surrounds the main cluster in a mostly circular shape, with many outlier stars embedded in the halo and extending well beyond.

Telescope: 102 mm f/9.8 refractor
Magnification: Eyepiece 26 mm + 2.8x Barlow = 108x

Bright with a well concentrated center and much brighter more intense core. Little to no resolution, however, many brighter outliers are visible. A chain of five stars are easily seen on the north edge of the cluster. The most prominent feature of this cluster, using the 102 mm refractor is the triangular shaped core.  Notes by Roger Ivester

 

The following write-up/article by Dr. James Dire, which accompanies the two images as posted above. 

M5
By Dr. James R. Dire
M5 is one of the finest globular star clusters north of the celestial equator. Located in Serpens Caput, the cluster is very easy to find. It is 8th degrees due east of 4th magnitude 109 Virginis, 11.5 degrees north of Beta Librae, and 7.5 degrees southwest of Alpha Serpentis. The cluster is a mere 20 arcminutes northwest of 5th magnitude MQ Serpentis (or 5 Serpentis).

M5 was discovered by Godfried Kirch in 1704. Kirch discovered it while looking at a comet nearby. Charles Messier catalog it in 1764. The integrated magnitude of the cluster is 5.6 and its diameter is 28.4 arcminutes. The cluster is an easy find in binoculars!

M5 contains hundreds of thousands of stars. Of those, nearly 100 are known to be RR Lyrae-type variable stars. These variable stars pin down the distance to the cluster at 24,500 light years. The cluster is one of the largest globular clusters in the Milky Way spanning 165 light years. Any object within 200 light years of M5’s center would be gravitationally bound to the cluster, unless moving with a radial velocity equal to the cluster’s escape velocity. M5 is thought to be 13 billion years old, one of the oldest globular clusters known.

Nearby 5 Serpentis is a binary star with components of magnitude 5.0 and 10.1, separated by 11.4 arc seconds. Slightly more than two degrees south of M5 lies another globular cluster known as Polomar 5. Located three times farther away than M5, Polarmar 5 shines at magnitude 11.75 and is 16 arcminutes in size.

I offer two images I took of M5. The first was taken with a 4-inch f/7.9 Stellarvue 102mm APO. The exposure was 30 minutes with an SBIG ST-2000XCM CCD camera. The bright star partial cut off to the lower left of the cluster is MQ Serpentis! The second image was taken with the same camera on a Discovery 10-inch f/6 Newtonian with a Televue Paracorr II coma corrector. The exposure was 60 minutes. The images speak for themselves!  James Dire 

M100 – NGC 4321 – Galaxy in Coma Berenices

Posted May 21, 2016 by rogerivester
Categories: Observer's Challenge Reports

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 

NGC 3077 – Galaxy – Ursa Major

Posted May 3, 2016 by rogerivester
Categories: Observer's Challenge Reports

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

NGC 2392 – Eskimo Nebula – Gemini

Posted April 15, 2016 by rogerivester
Categories: Uncategorized

Please click on the following link for the Observers Challenge report:

MARCH 2016 OBSERVERS CHALLENGE – NGC-2392

NGC 2392 – Planetary Nebula – Gemini
Date: February 2016
Observer: Roger Ivester
Telescope: 10-inch f/4.5 reflector
Sketch magnification: 190x
FOV: 0.32º – 19 arc minutes

Description: Very bright, bluish ball, appearing as a blurred star at low magnification. When increasing the magnification to 190x, the central star is easily seen. The edges are well defined, with a darker patch noted on the SSW edge. When increasing the magnification to 267x, using a 12 mm plus a 2.8x Barlow, the nebula became granular.

Date: January 31, 1998
Telescope: 10-inch reflector@ 256x (12.5 mm plus 2.8x Barlow)
Very bright, round, bright central star, with well defined outer edges. Greater concentration on SW edge.

Date: February 8, 2008
Telescope: 10-inch reflector@ 190x (12 mm plus 2.0x Barlow)
Much brighter than double planetary nebula, NGC 2371-2372 also in Gemini. The nebula is very bright, round, but has a hint of N-S elongation. The central star is easily seen at all magnifications.  RI 

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

Scanned Image 160930001

The following image was made by Jim Gianoulakis of Las Vegas.  Can you see the face of an Eskimo, or how about a clown-face, or maybe even the face of the beloved character, WC Fields?  

ESKIMO-MORE-COLOR-CROP-1

The Rosette Nebula – NGC 2237 – Monoceros

Posted March 21, 2016 by rogerivester
Categories: Observer's Challenge Reports

LVAS Challenge Link:

FEBRUARY 2016 OBSERVERS CHALLENGE – NGC-2237

The Rosette Nebula – NGC 2237 – Monoceros
Date: February 27, 2016
Telescope: 10-inch reflector
Eyepiece: 32 mm
Magnification: 36x
Field of View: 1.7º
Naked Eye Limiting Magnitude: 5.0

Faint circular nebula over 1º in diameter, surrounding open cluster NGC 2244. The cluster contains twelve brighter members with many fainter stars. Two pairs of wide doubles are located on the NW edge of the cluster. 

Faint circular nebula over 1º in diameter, surrounding open cluster NGC 2244. The cluster contains twelve brighter members with many fainter stars. Two pairs of wide doubles are located on the NW edge of the cluster.

A low power wide field eyepiece with an O-III filter are essential in seeing the vast wealth of faint detail found in the nebula. The SE section is the brightest and most concentrated. I have found that covering my head with a cloth improves the contrast of the nebula significantly. The texture of the Rosette is very uneven, with many lighter and darker areas.

Many amateurs feel that the Rosette can only be observed successfully under a very dark sky. However, I’ve enjoyed observing it many times over the past twenty five years from my moderately light polluted backyard, using a nebula filter.

Roger Ivester

Pencil sketch using a 10-inch reflector from my moderately light polluted backyard.  

Scanned Image 160920001

The following images courtesy of Dr. James Dire of Hawaii 

Telescope: SV102 Apo refractor:  Exposure 240 minutes (24 x 10)

Rosette01

Below:  Williams Optics 71 mm f/4.9 Apo refractor.  180 minutes (18 x 10) 

NGC2237


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