Category: Star Clusters

Owl, ET, or an Airplane?

NGC 457

NGC 457
Sketch and Details by Rony De Laet

Binocular Icon 50 : The Phi Cas Cluster, NGC 457.

This observation is the 50th entry in my little binocular project that I started on March 31 of last year. Most of these objects were not hard to locate, nor did I have to dig deep to find them. I even had to skip some objects, due to a lack of time or bad weather. If someone would have challenged me a year ago to find 50 sketch-worthy binocular objects, I might have called him crazy. Today I know better. I realize that one year is not enough to sketch the most interesting binocular objects. This project is still fun to do, prove of it is the collected dust on my Skywatcher refractor tube. Binoculars really have me fascinated with their magical views of the sky. People ask me if I don’t run out of objects. But so many binocular challenges lie ahead. We shall see how long my project will continue.

At this point, I want to thank all of you who have supported me in this project. Your friendly replies to these sketches have kept me going. Thanks a lot!!

NGC 457, the Phi Cas Cluster, is one of the most fascinating clusters in the whole sky. With an apparent magnitude of 6.4 and a size of nearly 20’, NGC 457 is not extra-ordinary bright, nor is it extremely large. Its true splendour comes from its stunning appearance in the eye-piece. It doesn’t take much of your imagination to see some kind of a creature, like an owl, or Spielberg’s ET, or an airplane. The cluster shows bar shaped body, with on both ends two stars, presenting the feet and the eyes of the creature. On both side of the bar, a small chain of stars represent the arms. With 8×56 bino’s, the cluster is difficult to resolve. The low power view reminds me of a fighter jet with glowing exhaust pipes. The 15×70 bino’s allow for a better resolution of the cluster’s main body. A comic book figure comes to my mind. It seems to wave with its arms. The mag 5 Phi Cas seems to show an orange hue. NGC 457 is 8.200 l-y away, residing in the Perseus spiral arm.

A nice little bonus is offered by NGC 436 at 40’ NW of NGC 457. In my 15×70 I could detect NGC 436 as a small amorphous patch. This little cluster does look very remote. In fact it is 10.700 l-y away and 25 times less luminous than NGC 457.
The Phi Cas Cluster is easy to look up. It can be found at 2° SSW of Delta Cas (the bright star on top of the sketch).

Site : Bekkevoort, Belgium ( 51° N )
Date : November 25, 2008
Time : around 20.30UT
Binoculars : TS Marine 15×70
FOV: 4.4°
Filter : none
Mount : Trico Machine Sky Window
Seeing : 2/5
Transp. : 3/5
Sky brightness : 19.64 magnitudes per square arc second near zenith (SQM reading).
Nelm: 5.3
Sketch Orientation: N up, W right.
Digital sketch made with Corel Paint Shop Pro X2, based on a raw pencil sketch.

(Note: if the sketch does look too dark on your monitor, try to darken the room.)

A Most Impressive Globular: Omega Centauri

Omega Centauri

Globular Cluster Omega Centauri
Sketch and Details by Janis Romer

Janis writes:

During the 1985 Astronomical League Convention in Tucson, Arizona local amateur astronomer Duane Nichaus held an open house at his home observatory. This “image” (sketch) was made using his 5.4” clear aperture F/15 folded refractor on the evening of June 18.

An Often Overlooked Globular Cluster M2

M2

M2
Sketch by Janis Romer

Charles Messier made his second catalog entry in September of 1760. M 2 is located in Aquarius a bit less than 5° north of Beta Aquarii. It has a stellar population of 150,000 suns and measures some 175 light years across. M 2 is surprisingly distant for a bright globular cluster at 37,500 light years and has a visual magnitude 6.5. With the eye at the eyepiece of a moderate size telescope, this globular appears 7 minutes across and somewhat oval in shape. It is worth noting for those that observe with a Dobsonian telescope or use an Alt.-Az. mount, that when M 2 is about 175° in Azimuth you can pan your scope straight up 13° to globular M 15 and after returning to M 2 you can pan down 22.5° to globular cluster M 30. That’s a globular triple.
Object: Globular cluster M 2 – Artist Janis Romer – Telescope – Criterion 8” f/8 Newtonian Reflector – Sketching Location: Pennsylvania, USA.

Written details by Frank McCabe

Great Globular M15

M15

M15
Sketch and Details by Eric Graff

Object Name: NGC 7078 (M15)
Object Type: Globular Cluster
Constellation: Pegasus
Right Ascension (2000.0): 21h 29m 58.3s
Declination (2000.0): +12° 10′ 01″
Magnitude: 6.3
Diameter: 18.0′
Concentration Class: 4
Distance: 30,600 light years
Discovery: Jean-Dominique Maraldi II, September 1746
NGC Description: ! Cl, vB, vL, iR, vsmbM, rrr, st vS

Date/Time: 28 September 2008 • 04:30-06:15 UT
Location: Oakzanita Springs, San Diego Co., California, USA
Telescope: Parks Astrolight EQ6 • 6″ f/6 Newtonian Reflector
Eyepiece: Parks 7.5mm Gold Series Plössl
Magnification: 120x
Field of View: 26′
Filter: None
Conditions: Clear, calm, 62°F
Seeing: Pickering 6
Transparency: NELM 6.4, TLM 14.3

It has been quite some time since I’ve sketched a really nice globular cluster, so after spending a bit of time chasing down a few dubious targets in northeastern Cygnus, I settled on a prolonged observation of Messier 15. The northernmost of the autumn sky’s three “Great Globulars” (the other two being M2 in Aquarius and M30 in Capricornus), M15 is easy enough to locate 4° northwest of colorful Epsilon Pegasi, tucked into a narrow triangle of 6th, 7th and 8th magnitude stars; these are HD 204862, HD 204571 and HD 204712, respectively.

Technically visible to the naked eye (I’ve never seen it thus, however), it is easily visible in binoculars as a slightly fuzzy star. At low telescopic magnification (30x), I see M15 as an unresolved nebulous patch with a blazing center and an irregular, spidery outline in a pleasing starfield. It is an interesting exercise to defocus the low-power field and compare the 6.1 magnitude glow of HD 204862 with the 6.3 magnitude glow of M15. Which one looks brighter to you?

At medium magnification (60x), I am able to resolve perhaps a dozen stars around the perimeter of the cluster. The core remains very bright and highly condensed. The entire face of the cluster is granular with stars just beyond the point of true resolution. Wispy streamers of faint starlight that drift in and out of visibility enhance the irregular outline of M15. At high magnification (120x) scores of distinct stars dance across the face of the cluster, spilling beyond its edges in curved arcs and narrow streams. Overall, the cluster is elongated slightly NNE-SSW with a bright central core. Countless minute suns seethe like a heap of restless diamond dust and several dark lanes crisscross the cluster, particularly toward the NE where several rifts run nearly parallel to one another; a peculiar dark patch SW of the nucleus is also noteworthy. Eighth magnitude HD 204712, 10th magnitude TYC 1127-128-1, and a handful of anonymous 13th magnitude stars share the high power field of view with M15.

This sketch was made on 67 lb. cover stock in a 3-inch circle with #2 mechanical pencil (0.5mm lead), blending stump and black ink (for the two bright field stars).

Merope’s Brilliant Pedestal

M45

M45 – The Pleiades
Sketch and Details by Rony De Laet

M45 is perhaps the most attractive open cluster for binoculars. It certainly is best viewed with a low power instrument. At a distance of 410 l-y this admirable open cluster still measures 2 full degrees across. Its true diameter is 14 l-y. M45 is with an age of 20 million years a relative young cluster, so young that the dinosaurs never saw Pleiades. Charles Messier included the cluster as the final entry of his first catalogue. Some say that Messier just added the Pleiades to arrive at 45 objects in total. M45 is a very rewarding object in any aperture. The tiny dipper can also be seen with the naked eye. It’s a fun exercise to count the number of stars visible with the naked eye. And do compare the Pleiades with the other great cluster: the Hyades. Keep in mind that the Hyades are 150 l-y away, while the Pleiades are 3 times further away. With the two clusters in your line of sight, the night sky suddenly shows a greater sense of depth, doesn’t it?
An interesting fact is offered by the nebulosity associated with the Pleiades. According to recent research, the open cluster is just passing through a nebulous cloud in the Milky Way. Photographs show this nebulosity very well. The visual observer must make use of the clearest nights to see a glimpse of this faint haziness. The brightest part of this nebula is NGC 1435, also called the Merope or Temple’s Nebula. Look for a faint comet tail S of Merope. I saw NGC 1435 with a 4” refractor before, so I knew where to look. Much to my surprise, I could detect the Merope Nebula with the 15×70. There is also a small ‘stripe’ of light visible just N of Merope. This small portion of NGC 1435 runs from SE to NW. The trick is to make the best of your averted vision while trying to avoid the bright glare from Merope.
I usually have little sense of colour. But when I studied this beautiful cluster, I compared its members with the surrounding field stars. While I swept the white looking Pleiades out of the field of view, the new field stars looked pale yellow to me. When I switched back to M45, the cluster suddenly looked rather blue. I repeated this exercise several times to convince myself that M45 does look bluer than the surrounding stars.

Site : Le Castellard Melan, France ( 44° N )
Date : September 29, 2008
Time : around 0.00UT
Binoculars : TS Marine 15×70
FOV: 4.4°
Filter : none
Mount : Trico Machine Sky Window
Seeing : 2/5
Transp. : 4/5
Sky brightness : 21.33 magnitudes per square arc second near zenith (SQM reading).
Nelm: 6.5
Sketch Orientation: N up, W right.
Digital sketch made with Corel Paint Shop Pro X2, based on a raw pencil sketch.

(Note: if the sketch does look too dark on your monitor, try to darken the room.)

Globular Cluster – M2

M2

M2
Sketch and details by Wade V. Corbei

Here is a sketch from back in August. As how I am blessed with clouds and rain, I thought I’d go through my sketchbook and start to catch up on digitizing some of my sketches.

This Globular is actually quite a treat in the EP, it is bright, compact and stars resolve fairly easily. Although not as spectacular as M13 or M15, this Globular nonetheless is quite a sight for those who enjoy looking at a gazillion stars crammed into a relatively small space.

The background stars set this Globular off quite nicely.

Celestial Lollypop

M3

M3
Sketch and Details by Jeff Young

While I suppose the bent stem looks more like a flower, M3 has always struck me as a fuzzy lollypop. However, I’ve attempted to render it as accurately as possible, without colouring the image with any impressions I might have gleaned, so that you can form your own, unique impressions.

M3 (NGC5272); globular cluster in Canes Venatici
sketched 4/31/2008 in County Louth, Ireland
as viewed through 16” Mak-Cass @ 150X; Pickering 8, NELM 5.5, SQM 20.6

My globular sketching technique is a bit different from that I use on other DSOs. I first place as many brighter stars as I can stomach using a medium-soft (HB) pencil. This sketch has about 120 placed stars, most of them in the globular itself. I then lightly smudge the image with a blending stick to show the extent of un-resolved stars. Finally, I place a harder pencil (3H) vertically on the drawing and rotate it slightly to form each of the smaller stars. These are placed randomly to reproduce the levels of shading I see in the eyepiece.

The sketch is then scanned into Photoshop and inverted.

Globular Cluster M30

M30

M30
Sketch and Details by Frank McCabe

Fall has arrived in my neighborhood and some of the Ash trees have begun dropping their golden leaves. On this evening the sky had cleared nicely and I took that opportunity to observe and sketch a favorite globular cluster in Capricornus. Globular cluster Messier 30 has for decades been a favorite to visit as it approaches the meridian. This cluster was discovered by Charles Messier on August 3, 1764. It is located less than 7° south of gamma Capricorni and when on my meridian is only 25° above the horizon. This object is 8 kiloparsecs (26,100 light years) from us and measures somewhere between 90 and 140 light years across. The visual magnitude of this cluster is 7.4 and is the deep sky showpiece of Capricornus. The small dense core is bright and noticeably ellipsoidal in shape. Most of the cluster stars that resolve well (mag.12) are to the north of the core. Two short chains of stars extending northward give this globular the appearance of legs in the inverted Newtonian telescope view. The brightest star in the field of the sketch is fifth magnitude 41 Capricorni. If you have a dark sky this is a fine target for a small telescope.

Location of M-30: R.A.21hrs. 40 min; Dec. -23° 11 min.

Sketching:

9”x11” white sketching paper; 2H, HB graphite pencils, black ink pen and a blending stump;
Scanned and inverted; brightness of some stars adjusted with MS Paint.
Scope: 18” f/5 Dobsonian: 12 mm wide field eyepiece 190x and 7.5 mm eyepiece 304x
Date and Time: 10-4-2008, 1:45-2:30 UT
Seeing: Pickering 5/10
Transparency: Average 3/5
NELM: 4.3

Frank McCabe

A Swarm within a Swarm

NGC 1502

NGC 1502 and Struve 485
Sketch and Details by Eric Graff

NGC 1502 and STF 485
Open Cluster and Multiple Star in Camelopardalis
Parks Astrolight EQ6 • 6″ f/6 Newtonian Reflector
7.5mm Parks Gold Series Plössl • 120x
Field of View 26′
31 December 2007 • 03:30-04:30 UT

Dangling off the southern end of Kemble’s Cascade, one the sky’s better-known asterisms, you will find the open cluster catalogued as NGC 1502. Easily visible, even at low magnifications, as an unmistakable glittering mass of stars, the cluster is dominated by a brilliant pair of 7th-magnitude snow-white suns separated by 18″ of arc in position angle 305°. These two are the principal members of the multiple star STF 485 (ADS 2984; CCDM 04078+6220).

Increasing the magnification brings better definition and resolution to NGC 1502. A 7.5mm G.S-5 Plössl yielding 120x provided the most pleasing view in my scope, and this was used in the sketch presented here. All of the cluster stars appear to be pure white (or nearly so). The brightest stars in the cluster are concentrated into a narrow east-west band of stars spanning the cluster’s 8′ diameter. Most of these are members of the STF 485 system.

The Catalogue of Components of Double and Multiple Stars (CCDM) lists 16 members for STF 485 with magnitudes ranging from 7 to 14; these are designated (A-P) as indicated on the inset. Components C, E, F, G and M are very challenging due to faintness (mags 11.9-14.1) and proximity to A and B; the remaining members are quite easy by comparison. Component B is also a variable star, designated SZ Camelopardalis. It is a Beta Lyrae-type eclipsing variable with a period of just under 2.7 days and a magnitude range from 7.00 to 7.29. While component A might seem like a convenient comparison star for making magnitude estimates of SZ, it is suspected of being variable as well, with an observed amplitude of about 0.1 magnitude. Components H, I and J are also catalogued separately as STF 484 (ADS 2982); components K and L are catalogued separately as Holmes 3 (ADS 2989).

William Herschel discovered NGC 1502 on November 3, 1787 with his 18.7-inch reflector. It is sometimes called the Golden Harp Cluster; it contains 63 member stars and lies 2,650 light years away in the direction of Camelopardalis. Its age is estimated at 5 million years.