This is a 3-part report on the Mersing astro expedition (at Telok Sari) over the weekend of Fri 12 April 2013 to Sun 14 April 2013 (Remus' group).
This part 1 is on the astronomy aspects of the trip. Part 2 would be a photo essay with day-time photos taken during the trip to Telok Sari, at Mersing, and at Telok Sari itself. Part 3 would be on the amazing lightning display which we saw on the 2nd night.
First, on the astronomy. I decided this time to use a basic all-manual alt-azimuth setup for both nights, and eschew electronic goto / tracking mounts. It would be a good refresher of constellation recognition and star-hopping skills in case I get too reliant on gotos. I find that manual star-hopping also gives a more connected experience with the night sky, and it is very satisfying when one manages to eventually find a faint DSO in the eyepiece and confirm it with the star charts.
The telescope was a Skywatcher 120mm ED (5-in class) f/7.5 light-weight refractor, coupled to a Vixen Porta II mount on a Manfrotto 475B tripod. Pointing devices were a Rigel 1x quickfinder set atop a 8x50 finderscope.
Eyepieces: Explore Scientific 34mm 68-deg, Meade 5000 SWA 24mm 68-deg, Explore Scientific 14mm 100-deg, Pentax 14mm XL, and 2x and 3x apo barlows. Plus an Orion Ultrablock narrowband filter and a DGM Optics OIII filter.
The 120mm ED refractor (f.l. 900mm) provided a very good balance of a noticeably high resolving power and also wide fields of view. With the 34mm 68-deg eyepiece, the magnification was only 26.5x and the true field of view was a wide 2.6 degrees, allowing me to pan the skies through endless star fields and also frame parings of DSOs. The best eyepiece was however the superb 14mm 100-deg Explore Scientific, and the views of open clusters and nebula with that eyepiece through the 120mm refractor were marvellous.
Star charts used were a S&T Pocket Sky Atlas and Bright Star Atlas 2000. Apps: the superb Sky Safari Plus and Sky Safari Pro for Android. I also prepared a to-watch list of deep sky objects on an Excel file.
In addition to the scope, I brought a Canon 15x50 IS binoculars, and a dSLR for some simple untracked wide-field photography.
Here is the telescope set-up near the chalet:
I think I was one of the few flag carriers for mainly visual astronomy during the trip. Alas, we seem to be in the minority now!
Weather-wise, it was mixed. The several days before that Friday were very cloudy in Singapore and, from the satellite imagery, throughout most of southeast Asia. Most of us had little hope for any clear weather that weekend. However, on Thursday night the skies cleared up dramatically overnight and there were bright blue skies on Friday morning. It was one of the most complete turn-arounds in cloud cover conditions I've seen.
On Friday night the skies were about two thirds clear from sunset to around 4.30am. Transparency was good but not great. We could see the Dark Horse in the central bulge of the Milky Way as well as the dark rifts in the Aquila-Cygnus region. The Crux-Carina area was also very clear for good stretches of time. The Ursa Major and Leo-Virgo regions were also good most of the time. However, clouds moved through the sky throughout the night which made viewing objects sometimes difficult, e.g. as soon as I had located a galaxy or planetary at low powers, the clouds would obscure it before I could switch to higher powers.
Nevertheless, it was a productive night of very enjoyable visual astronomy and I would rate it a 7/10 overall.
The views through the 120mm ED refractor with the 100-deg apparent field of view of the sharp 14mm Explore Scientific eyepiece, of the Eta Carina nebula, the rich open cluster NGC3532 nearby, and the Small Sagittarius Star Cloud (M24) in Sagittarius, were together perhaps worth the whole trip there. These were simply superb!
On the 1st night, I observed the following DSOs through the scope:
Open clusters: M35 (Gem); M36, M37, and M38 (Aur); M46 (with planetary nebula NGC2438) and M47 in Puppis which I could frame nicely in one field of view at lower powers; and NGC3532 Carina (the best OC of the night by far alongside M24).
Globulars: Omega Centauri; M22 (Sgr); M13 (Her); M107 (Oph); and NGC6304 and NGC6316, both in Oph which I had hoped were comets when I first saw them, but alas a check with the charts showed were not.
Nebulae: the venerable M42 in Orion, Eta Carinae, and the Swan Nebula (M17) in Sgr. Plus the Lagoon Nebula (M8) and Trifid Nebula (M20), both in Sgr, through the 15x50 bino. I also viewed the Pipe Nebula (dark nebula, which is a part of the Dark Horse) through the 15x50 bino.
Galaxies: M104 Sombrero (Vir); M65, M66, NGC3628 Trio in Leo; M51 Whirlpool and its companion NGC5194 (Cvn) were distinct patches; and about 20-30 distinct galaxies in the Virgo cluster (which unfortunately I did not have the time to identify individually). Alas, I missed NGC4565 (the Needle Galaxy) in Com., as the clouds were blocking it when I twice tried to view it, and then forgot to try it again thereafter.
Planetaries: Blue Planetary NGC3918 (Cen); NGC2438 in M46 (Pup), M57 Ring Nebula in Lyra. I wished I had viewed more of them but did not have the time.
Star Cloud: M24 (the Small Sagittarius Star Cloud), which Kelvin highlighted to me. I kept saying to him that I could see a million sharp stars in the 14mm ES eyepiece. This is simply one excellent object to view through a refractor.
I attempted to view comet C/2012 L2 (LINEAR) in Taurus after evening twilight in the NW. The comet was then reported at around mag 10-11. However, even though I managed to pin the location down to a few mag 11 stars in the eyepiece I could not see the comet. It was probably too diffuse and the sky conditions not transparent enough.
The 2nd night (Sat night) was unfortunately very different from the first. It was mostly cloudy after sunset and we had a few patches of clear but muted skies from about 8pm for about 1 hour. Thereafter, it remained totally cloudy till dawn. Astronomy-wise, I would rate the 2nd night a 1/10. However, we were treated to an amazing lightning show from around 3.45am. See Part 3 of this report.
In that 1 hour from 8pm, I managed to view the following DSOs in the scope: M42 in Orion; the open cluster M41 in Canis Major; and 4 galaxies in the Leo I Galaxy Group (M95, M96, M105, and NGC3371, each identified individually).
Here are 3 images of the starry background with ourselves silhouetted in the foreground. The first 2 images were taken on the 1st night, and the 3rd one on the 2nd night.
Myself viewing through the 120mm refractor, with Centaurus-Crux-Carina in the background.
Canon EOS 60D on a photo tripod, untracked. Sigma 17-70mm lens at 17mm. 20s, f/2.8, ISO1600. Image brightness and contrast, and colour, adjusted.
Kelvin inspecting the sky at 1x power, and myself at 64x, with the full glory of the central Milky Way in the sky.
Canon EOS 60D on a photo tripod, untracked. Sigma 17-70mm lens at 17mm. 15s, f/3.5, ISO3200. Image brightness and contrast adjusted.
Kai Fon viewing the stars on the 2nd night. Notice the trash-bags light shield on the fence which I had set-up.
Canon EOS 60D on a photo tripod, untracked. Sigma 17-70mm lens at 17mm. 15s, f/3.5, ISO1600. Image brightness and contrast adjusted.
End of Part 1. Hope you enjoyed reading the report.
Parts 2 and 3 coming-up sometime soon.
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Enjoyed reading your report. Looking forward to part 2 and 3.
![[smilie=admire.gif]](./images/smilies/admire.gif "admire")
