Molokai Observing Report

Part 1

by Andrew Pierce


My family and I spent a week on Molokai and northern Oahu starting May 26, 2000. I brought 7 x 50 binos, a new 150 mm Intes/Orion Mak-Cass scope, a Skyview Deluxe mount and a target list of about 30 southern deep sky objects. The optical tube weighs about 10 lbs and is a carryon. The mount w/ counterweights is about 30 lbs and can be disassembled to fit in a suitcase.

On May 27, our first night at the Molokai Ranch, on the western end of the island, there was a scheduled "Stargazing" program which the ranch puts on with Litebox telescopes. For more info check www.litebox-telescopes.com/Molokai Ranch/index.html. Barry Peckham sometimes hosts, but on May 27 Chris and Janelle Trusty ran the show with a 12.5 inch Litebox dobsonian. The site was Paniolo Village Pavilion which is at about 1000 feet. Unfortunately it started to rain about 9:00 pm so the actual observing was cut short. I did get to help move the scope and got a glimpse of M51.

Despite the weather the program was a memorable experience. Mrs. Trusty explained how the ancient Polynesians used Polaris, which they could only see when they traveled far north of their original homes, and Arcturus to navigate to Hawaii. Polaris is known as Hokupa'a, the Stationary Star, and Arcturus is Hokule'a, the Star of Happiness. Arcturus, at dec 19 10' crosses the zenith when you reach the latitude of the island of Hawaii. It was strange to see Leo almost directly overhead and Arcturus heading that way.

Lookin south for Omega Centauri I noticed a pattern of five bright stars through the mist. I knew one was probably Alpha Cen, but we couldn't tell which until it cleared slightly and a sixth star appeared. The pattern was now unmistakable --Crux, the Southern Cross w/ Alpha and Beta Centauri.

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This was the first time I'd seen the Southern Cross. It was truly an amazing sight, looking rather surreal and bright through the haze. It must have been very inspiring to the early Christian navigators. With my 7x 50s Crux just filled the field, including a fifth bright star that is familiar from the design on a certain large beverage can. I could not split Alpha Cen with the binos.

Returning to our base at the beachside Kaupoa camp I did some naked eye viewing from a hammock. It's about 70 degrees there at night. The number of bright stars in the Centaurus region was surprising. It turned out I was seeing the 100 or so stars of the Centaurus Scorpio Association, which is just below our Northern California horizon.

The next evening, May 28, began with a leisurely watch for Mercury from our westward facing beachside dining area. The sun set into the low clouds over Oahu. Sirius was the first star seen, at the same elevation, but too far south to be a convincing Mercury. The planet appeared about ten minutes later, directly over the spot where the sun had set. Its ID was confirmed when Gemini appeared above it. Mercury was not a disc in the binos, but appeared steadier and with less refracted color than the bright stars. It was almost exactly as bright as Procyon. The verticality of the ecliptic made it easy to visulize the earth slowly rotating, carrying us away from the sun, exposing Mercury near its greatest eastern elongation, then hiding it in turn.

I finally got a chance to see something with the scope that night. Mercury, seen just as it disappeared, intermittently showed its half illuminated shape. I then moved to a field about 20 yards from our "tentalows" (two steel framed canvas structures). Although there is a small light dome from Oahu to the west, it was plenty dark. I didn't do a formal test, since I didn't see the Bootes count thread til I got back, my notes indicate that M3, an extended mag 6.4 object, was naked eye. M51 could be seen in binos, a first for me. Also it got noticeably easier to see my charts and equipment after the Milky Way rose. It was certainly darker than Coe and comparable to Pinnacles.

The globular cluster Omega Centauri was my first target, NGC 5139. My observing journal lapses into exclamation marks at this point. It is an overwhelming sight in the 150 mm scope, especially with a 26 mm eyepiece. (I did virtually all my observing with 26 and 32 mm Plossls). Its also impressive in binos and the 30 mm finderscope. The qualities that make it special are are not only its size and brightness, but also the sheer number of points of light you can see. The Mak is perfect for this this object. Those of you with 18" scopes might want to put on your sunglasses before viewing it from a southern site.

My next target was NGC 4945, found after an easy Centaurus star hop. It looked elongated N-S which is about right for this edge on barred spiral galaxy.

Alpha Centauri was rising so I popped over there. I knew it was celebrated double, but I was still surprised by how impressive it was, especially since at dec -60 50' it was barely above the trees. Molokai is about 22 10' N latitude. The two main stars were bright and fat at 75x, but clearly separated. The colors were yellow-orange and yellow-oranger. Upon reflection, it occurred to me that the B star has to be the brightest B star in our sky. A chart check suggested that the next brightest comes is nearby Acrux B, with Castor B in third place.

I then went north to M84 and 86 but decided the six inch scope was not the tool to tour Virgo. I did stop at M104, which appeared as an obvious edge on spiral with a central bulge. No dark lane however.

Since I was in the neighborhood I visited NGC 4361, the planetary in central Corvus. It was still a pretty nondescript medium size planetary, just like at home.

Next stop M68, the globular in Hydra. It showed some resolution at 130x but didn't improve with more magnification. Seeing was mediocre and it was very windy. M83, also in Hydra, was more rewarding. The spiral structure was barely discernible with averted vision and some imagination. Since I could see M51 in the binos I decided to compare them in the scope. The spirality of M83 was more apparent than M51.

Sag. was rising, as was Cygnus, so I toured them with binos, but decided to save them for a night when I could stay up later. (See Part 2 for more). Just before packing up I lay on my back in the grass and saw Arcturus near the zenith.