Author: Jeremy Perez

A Freckle on the Sun

Mercury-Solar Transit

Mercury-Solar Transit
Sketch and Commentary by Jeremy Perez
Move cursor over sketch to see labels.

On Wednesday, November 8th, 2006, Mercury was due for a solar transit. Now, in my neck of the woods, that just happens to be a work day. So I planned to set up the scope during lunch in the parking lot, or outside the lunchroom. The only thing I needed was a solar filter. A couple years ago, a very kind and generous amateur astronomer from Phoenix, Scott Kroeppler, sent me a couple small Baader solar film samples. Other than some casual, unmagnified looks at the sun, I hadn’t put them to good use. Until now. I stayed up the night before, rigging these two 1-inch square pieces of solar film and a sewing hoop to an 8 inch square piece of foam core. I wasn’t sure if it would work, but the next morning, I pulled into the parking lot at work, put my mangy, home-made solar cap on the front, and got a handheld look at the sun for the first time through my own scope. Not only did it work great, but I was pleasantly surprised to see a huge sun spot easing over the solar limb.

So I got to work, and then about 15 minutes before the beginning of the transit, I put it all together on the patio outside the lunch room where I had the best opening between all the trees. I didn’t start quite early enough, because by the time I got everything set up and the solar cap taped on securely, Mercury was already well inside the solar disc. It looked just like a printed period against blue-white filtered circle of the sun. It had entered just south of the massive sunspot I noticed earlier. A couple fainter sunspots rested on the opposite side. At that point, I made my first solar sketch, and noted how easy it would be to really exaggerate distances and proportions across the sun’s face. I was excited to see that light, textured, filamentary features were visible around the sunspots. As I studied these features, I noticed that it didn’t take long for Mercury’s motion to become apparent.

Over the next 45 minutes, I invited passing coworkers to have a look. They all seemed happy to get a look at the transit, particularly after reading about it in the newspaper the day before. As folks walked up to the eyepiece, I tried to coach them a bit with the sketch to be sure they didn’t confuse the sunspot for Mercury. Quite a few commented on how very tiny the little planet appeared. Several of them were even able to make out the two relatively faint sunspots over on the western limb as well. After a little more than an hour, I moved the scope to an out-of-the-way spot, and went back to work.

At about 20 minutes before the end of the transit, I raced outside to find that the sun was completely hidden behind trees where I had the scope set up. With a bit of scouting, I moved the whole thing into the parking lot about a hundred yards to the north where I had a clear vantage. And here I got to watch that perfect little dot edge closer to the western edge of the sun. At about four Mercury diameters from the edge, the whole shebang began to sink behind a tree-lined ridge a mile to the west. So I missed seeing Mercury merge with and disappear into the darkness on the other side of the sun. It was still a fascinating event to witness, and since Mercury won’t do this again until 2016, I’m glad I was able to fit it in.

The sketch at the top of this post was overlayed onto a digitally generated disc with limb darkening that estimates what I saw through the eyepiece. The next time I sketch the sun this way, I’m sure I’ll want to include the lighter features, which will mean generating that limb darkening manually and erasing through it.

Subject Mercury – Solar Transit
Classification Planetary/Solar
Date/Time November 8, 2006, 12:33 – 04:54 PM MST (November 8, 2006, 07:33 – 11:54 UT)
Observing Loc. Flagstaff, AZ
Instrument Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag. 25 mm (48X)
Conditions Clear, breezy
Seeing Ant. IV

Hickson 44

NGC 3190

Hickson 44
Sketch and Commentary by Kiminori Ikebe

NGC 3185 Leo galaxy
NGC 3187 Leo galaxy
NGC 3190 Leo galaxy
NGC 3193 Leo galaxy
HCG44

1997.01.12 01:27
32cm at 110x

A fine group of four different-type galaxies.
NGC 3185: The largest of the group, but faint and diffuse. Elongated. A fainter halo appears to envelop the galaxy, but not confirmed.
NGC 3187: Barely detectable. A long, narrow shape is barely discerned.
NGC 3190: A sharp, long, spindle-shape. The brightest of the group. A stellar nucleus and a small central condensation.
NGC 3193: Small and round. A dull glow of a stellar nucleus and very weak central condensation.

Gazing into Cleopatra’s Eye

NGC 1535

NGC 1535
Sketch and Commentary by Eric Graff

NGC 1535
Planetary Nebula in Eridanus
Parks Astrolight EQ6 • 6″ f/6 Newtonian Reflector
7.5mm Parks Gold Series Plössl + 2x Barlow • 240x
Field of View 13′
Lumicon OIII Filter
31 December 2007 • 04:30-05:15 UT

Secluded in an out of the way region of meandering Eridanus, the planetary nebula NGC 1535 is lost in a world of its own, far from any conspicuous guide stars. It is unfortunate that such an exceptional object languishes in relative obscurity; it is, arguably, the finest deep-sky wonder to be found on the shores of the celestial river. I found this hidden treasure by centering my scope on 5th magnitude 39 Eridani (the brightest speck of light within a triangle formed by Gamma, the Omicron1,2 pair, and 53 Eridani) and sweeping 2½° due south.

At low to moderately high magnifications NGC 1535 appears as a slightly out-of-focus blue-green star of about the 9th magnitude. It is this low-power aspect that has earned it the moniker “Ghost of Neptune”. In the low-power, wide-field ocular the planetary is situated near the center of a ragged semi-circle of 8th-11th magnitude stars with a radius of about 30 minutes of arc.

To understand NGC 1535’s other nickname, “Cleopatra’s Eye”, you’ll need to push your scope to the higher magnification ranges. I used a 7.5mm Parks G.S-5 Plössl coupled with a Parks G.S. 3-Element 2x Barlow for a magnification of 240x in making the sketch presented here. Magnifications above 200x are generally required to separate the 12th magnitude central star from the bright inner ring. This ring is somewhat irregular, about 20″ across, slightly brighter on the eastern side, darker in the middle and surrounded by a faint, diffuse outer envelope to a diameter of about 45″ and elongated slightly toward position angle 35°.

Sir William Herschel discovered NGC 1535 on February 1, 1785 with his 18.7-inch reflector. The expansion velocity of the outer atmosphere of this dying star has been measured at 19 km/sec. NGC 1535 lies at a distance of about 5,200 light years; it actual diameter is about 1.2 light years. It is five times further away and 3 times larger than the famous Ring Nebula (M57) in Lyra.

A Wide Look at M35

M35

M35
Sketch and Commentary by Rony De Laet

While Gemini is far past its optimum appearance in the sky, the view of M35 is still very exciting in a pair of binoculars.

The open cluster M35 was probably discovered in 1745 by Philippe Loys de Chéseaux. In 1764 Charles Messier added the object in his famous catalog with the entry number 35. The cluster has once been called the Shoe-Buckle Cluster for an evident reason. This misty patch can easily be found at Castors foot, between Eta and 1 Geminorum. At a distance of 2.700 l-y, M35 is visible as a mottled, misty patch to the naked eye under very dark skies. It shines with a total magnitude of 5.1.

M35 is a very rewarding object in small binoculars. Once Eta Geminorum is centered in the field of view, the sparkling cluster is easily visible near the western border of the field. I could partially resolve the cluster with my 8×56. Four stars were visible with direct vision, while a total of 14 stars could be picked out of the glow with averted vision. A few dark lanes were visible as well. Unfortunately, the sky was not very clear during the observation and M35 was approaching the north-western horizon. I saw a brightening near the position of NGC 2158, but I could not confirm its presence. M35 is certainly an object to return to next year, when it appears again near zenith. The bright star near the bottom left corner of the sketch is Eta Geminorum.

Observing data:
Date : April 7, 2008
Time : around 20.30UT
Binoculars : Bresser 8×56
FOV: 5,9°
Filter : none
Mount : Trico Machine Sky Window
Seeing : 2,5/5
Transp. : 2,5/5
Nelm : 4,8
Sketch Orientation : N up, W right.
Digital sketch made with PhotoPaint, based on a raw pencil sketch.

Light at the Junction of Fabricius and Janssen

Fabricius and Janssen

Fabricius and Janssen
Sketch and Commentary by Frank McCabe

On this evening of observing the young, spring, crescent moon just past nightfall, I was preparing to sketch crater Santbech when my eye was drawn to the terminator region of the Vallis Rheita and on south. Back in February of this year I caught this region at a time near sunset but this evening I was looking at an opportunity to capture an interesting crater rim illumination as long as I began drawing quickly. Along the terminator to the south of the valley is Nectarian crater Metius. This 90 kilometer cavity was completely in shadow except for its rim which was well displayed in morning light. Immediately south-southwest young 80 kilometer crater Fabricius was also displaying most of its rim. What captured my attention to this area initially was the way the light was illuminating the shared arcing walls between Fabricius and its neighbor Jannsen. The Jannsen component of this illuminated arc appears to be the centrally located slump block that dislodged at the time of the Fabricius forming impact (see: The Modern Moon by C. Wood page105). To the east of Pre-Nectarian crater Jannsen the paired craters Steinheil (70km.) and Watt (68km.) were putting on a show of their own. The shadows demonstrated the greater depth of Steinheil when compared to Watt. Finally on to the south along the terminator crater Rosenberger C at 48 kilometers marked the end of the large crater collection along the terminator in this sketch.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 8”x 11”, white and black Conte’pastel pencils and a blending stump. Brightness was slightly decreased (-4) and contrast increased (+5) after scanning using Microsoft Office Picture Manager.

Telescope: 10 inch f/5.7 Dobsonian and 9mm eyepiece 161x
Date: 4-10-2008 0:30 – 2:00 UT
Temperature: 4°C (40°F)
high clouds, calm
Seeing: Antoniadi III
Co longitude: 320.6°
Lunation: 3.9 days
Illumination: 20.4 %
Phase: 126.2°
Observing Location: +41°37′ +87° 47′

Frank McCabe

McNaught-Hartley in Motion

C/1999 T1 McNaught-Hartley

C/1999 T1 McNaught-Hartley B

C/1999 T1 McNaught-Hartley
Sketch and Commentary by Martin Mc Kenna

The top sketch shows C/1999 T1 Mc Naught – Hartley on Jan 14th 2001 at 06.30 LT low in the eastern pre dawn sky between Libra and Serpens in the 8″ F/10 S.Cass at 77X. Despite frozen mist, a harsh ground frost and a moon 4 days after full I could see this 8th magnitude comet quite easily and even picked out two tails, one of gas and one of dust.

The 2nd sketch shows the comet on Feb 25th 2001 at 05.47 LT in Hercules at magnitude 8.8. The sketch shows the comets NE movement over a 2 hour period.

This comet is very special to me as during Dec it was moving from the southern hemisphere into the northern hemisphere and I was desperate to see it. I tried to located it on every clear night even when the moon was full hoping to catch the comet as cleared horizon obstructions however despite trying so hard I could not get low enough in the eastern sky. The pre dawn hours of Christmas morning were cold, sharp with heavy snow on the ground and the corrector plate was threatening to freeze over at any moment. I guided the 8″ into the low eastern sky and began a hunt for new comets. 5 Minutes later as I swept through the southern section of Libra that was just rising over my neighbours rooftop and I found the comet! I was delighted beyond words and it felt like this comet was my Christmas present from the sky. I followed this icy wander on every clear night for months afterward as it moved from the morning sky into the evening sky. Mc Naught – Hartley taught me alot about observing comets, the long hours spent watching this comet have benefited me greatly with the future comets I have encountered.

Lunar Clock Face

Petavius Crater

Petavius Crater
Sketch and Commentary by Carlos E. Hernandez

I made an observation of the crater Petavius and environs on July 31, 2007 (03:00-04:15 U.T.) using my 9-inch (23-cm) F/13.5 Maksutov-Cassegrain. Petavius (25.3*S, 60.4*E) measures 110 miles (177 km) in diameter containing a central mountain range, prominent rille (Rimae Petavius, (50 miles (80 km) in length) and ridges over it’s eastern and northern sections. Smaller rilles are also noted over it’s floor. Wrottesley (23.9*S, 56.8*E) is the crater noted along the western border of Petavius. The elongated crater to the east of Petavius is Palitzsch (28.0*S, 64.5*E) which measures ~25 miles (41 km) and appears half illuminated and half in shadow. Hase (29.4*S, 62.5*E) is a disintegrated crater that lies to the south of Petavius and measures ~52 miles (83 km). Several craters in shadow (with illuminated rims) appear towards the terminator.

The observation was made using graphite (4H to HB) then scanned into Photoshop and adjusted.

Links to Petavius;
http://www.lpi.usra.edu/resources/cla/info/f2/
http://en.wikipedia.org/wiki/Petavius_(crater)
http://www.lpod.org/?m=20060814

The Box in Coma Berenices

Hickson 61

Hickson 61
Sketch and Commentary by Bill Ferris
Move mouse over sketch to see labels.

Hickson 61: Galaxy Cluster (Coma Berenices)
RA: 12h 12.3m / DEC: +29º 10′.8
Instrument: 18-inch Obsession

This quartet can be found in northwestern Coma Berenices. 4.3 magnitude Gamma (15) Comae Berenices shines as a naked eye landmark about 3 degrees to the east. My sketch presents a 199X view in the 18-inch Obsession. The brightest of the four galaxies is NGC 4169, also known as Hickson 61A. This 12.2 magnitude S0-type galaxy covers a 2′ by 1′ area and is aligned northwest to southeast. It is westernmost of the four, becomes gradually brighter towards the middle and displays a stellar core. The slender galaxy 2′ to the northeast is Hickson 61B. Hickson 61B is a 13.6 (B) magnitude spiral seen nearly edge-on. It covers a 5′ by 0′.7 area in my drawing, tapers in brightness towards the ends and is aligned northwest to southeast. Also known as NGC 4173, this galaxy’s ragged form shows no hint of stellaring at the core. The other edge-on spiral in the field is Hickson 61C, listed in Dreyer as NGC 4175. It’s a 14.2 (B) magnitude object covering a 1′.8 by 0′.4 area. NGC 4175 features a bright mid-section and has nearly the same position angle as its sibling to the northwest. Finally, NGC 4174 equals Hickson 61D. At 14.3 magnitude in the blue and 1′ by 0′.5 in size, this stellar metropolis is the smallest and faintest of the bunch. Aligned northeast to southwest, NGC 4174 features a faintly stellar core within a surrounding disk of even brightness.