I think this site is overall a very good obs site in terms of distance from Singapore, dark skies, good observing conditions, and good ground conditions.
Background
Over two Saturday afternoons, two recce expeditions were made to scour the coastal region of east Johor to look for a new good observing site.
I had a few weeks earlier examined satellite imagery of the region south of Telok Mahkota (Sedili) on Google Earth and many places looked to have good potential. A cross reference with the light pollution imagery on Google Earth showed this region to have very low local light pollution conditions and to be outside the main light dome of Singapore and JB.
Last Saturday, 21 March 09, I drove up to the Sedili region with RLow and Acc. We drove for miles in the region south of Tanjong Sedili. Eventually, we decided that 3 places had good potential. However, due to time constraints, we later observed for a while at another site north of Tanjong Sedili under poor cloud conditions.
Yesterday, I joined RLow, his wife, and Elton on another recce expedition. This time RLow drove around the area north of Tanjong Sedili right up to Tanjong Leman (which is the ferry point to Pulau Sibu and other islands). I can report that that region is almost exclusively comprised of palm oil plantations for miles on end. We did not find a single site which we considered to be suitable.
Palm oil plantations are not good for astro observing for two reasons: I've heard that there are a lot of snakes in these plantations due to the large number of frogs and indeed we saw some road killed snakes. There are a lot of workers in the plantations who carry parangs (machetes) with little else to do. Indeed we saw quite a number of people on motor bikes and others lingering around who did not convey a sense of serenity to us.
The ferry terminal at Tanjong Leman has toilet facilities, good shelter and a large carpark. However, the security guard there told us that the carpark is closed a night, and I think this is because cars are parked there whilst their owners holiday in the offshore islands overnight. The beach area at Tanjong Leman is pleasant enough with many families. However, no site with low obstruction was found. The beach area is several hundred metres from the ferry terminal. There are also about 2 chalets in the beach area.
Eventually, at about 6.30pm yesterday, we decided to head back south to the small town of Tanjong Sedili to have dinner. Tanjong Sedili is about 40km northeast of Kota Tinggi, and is situated at the northern end of Telok Mahkota (Jason Bay). I can also report that Tg Sedili has two good food options. At the coffee shop right beside the ferry jetty, the roti prata (canai) is excellent. Its chewy and fluffy but not oily. However, ensure that they make one fresh and newly fluffed up or else it will be quite flat. The coffee shop is closed for dinner.
We had dinner at another coffee shop by the road side called "Restoran Sedili Seafood - Masakan ala Thai". We all had fried rice (Nasi Goreng) with chicken or seafood. The fried rice is excellent as it has very good "wok hei", I think in Cantonese it means breath of the wok, i.e. good flavouring from a very hot frying pan.
After dinner, at about 8pm, as the skies were not too cloudy, RLow decided to drive south to one of the potential sites south of Telok Mahkota which we had found the previous Saturday. And so, below is a brief obs report.
Observation session report - site 11.0km south of Telok Mahkota.
We arrived at the site at about 8.30pm. I named the site "Sedili South Centauri". We located the site using GPS coordinates obtained the previous week.
The road turn-off entrance to the site is at:
1°45'21" North, 104°11'48" East.
If using GPS, you need only concentrate on the North coordinates as the road runs north-south.
The road turn-off to the site is on the seaward side (left hand side) as heading south from Telok Mahkota, and is 11.0km (road distance) south of the south bank of the river at Sedili Kechil, i.e. 11.0km after crossing over the bridge. Sedili Kechil is a small village at the south end of Telok Mahkota (Jason Bay), and has two chalets.
The road to the site from Telok Mahkota heads in the direction of Desaru, which is very far away.
The road distance from the site to the customs checkpoint at Johor Bahru via Kota Tinggi was later measured at exactly 100km. Driving back at 4am, we took 1 hr and 20 mins to get from the site to the JB customs, at speeds of 80-110 km/h.
Site conditions:
The site is an open area with dimensions of approx 35m x 35m. The site is about 250m from the sea shore. The sea shore itself is perhaps 20m below as the road and the site are in a slightly elevated area. You can see the sea and off-shore ships from the site, which is a nice touch.
Obstruction all round is about 10 to 20 degrees, which is good enough.
See a photo below of the site which I took last Saturday.
The site is just off the road, but the good thing is that there are hedges at the area bordering the road so you are quite obscured from the view of those driving along the road. However, you can be seen through the site entrance. If you do not wish to be disturbed by curious drivers, I suggest maintaining low lighting.
From about 8.30pm to midnight, a vehicle passes along the road every 5-10 minutes. After midnight, its about 3-4 per hour.
I think when observing, there should be at least 2 or 3 male adults present for safety reasons.
There are no street lamps in the entire region south of Telok Mahkota.
The ground at the site is flat, and is comprised of gravel (small stones). There is no grass in except at the fringes.
The region of the site is very rural and sparsely populated, with no villages (kampongs) at all. The nearest village is Sedili Kechil mentioned above. The vegetation of the whole region is I think secondary forest, and importantly, not palm oil plantations. Hopefully it remains that way.
A word of caution though: we were plagued by buzzing mosquitoes throughout the night. They seemed to have encountered humans for the first time for they kept buzzing around our faces from 8pm to 4am. I sprayed a lot of Deet repellant: I was not bitten but they kept flying around my ears nevertheless. It was so irritating! I suggest a multi-pronged warfare approach if observing at this site: spray repellent, burn lots of mosquito coils, and use some sonic anti-mosquito device (add: and also spray insecticide).
Observation report:
When we arrived at the site at 8.30pm and sprang out of the car, we were wonderfully greated by the majestic sight of a large band of the Milky Way running brightly and contrastingly across the sky from the Carina/Vela/Puppis area right across to Orion and Auriga. The band of the Milky Way ran down to about 10 degrees above the horizon esp in the southeast.
It was just two nights after New Moon.
Within 2 seconds, the decision was made: "Ok, deploy!" This area was decided on the spot to be almost as good as Telok Sari.
So RLow and Elton quickly set-up Elton's 18" Obsession, which is very likely the largest aperture in Singapore (and some say JB). I assisted with the white lighting.
The area is dark, and there is a large light dome in the southwest which marks Singapore and JB. There is a smaller and dimmer light dome in the west which I think is caused by Kota Tinggi town.
I did some quick observing with 15x50 IS binoculars and saw huge swaths of innumerable multitudes of stars especially in my favourite star field areas of Canis Major, Puppis, Orion and Auriga. To me, these large star fields are anytime better than any open cluster. These fields are just like one contiguous cluster!
Unfortunately though, that initial 15 minutes was the best until about 3am. Later on until 3am, there was a persistent light layer of high haze which muted most but not all views of DSOs, as well as large patches of clouds drifting about. Nevertheless, throughout the night, the sky was overall about 70% cloud free.
Nevertheless, we did very productive observing. I think RLow and Elton may provide the details. In summary, we saw galaxies (e.g. the Trio in Leo, Centaurus A, M51, the galaxies in Virgo-Coma esp the Smiley Face, Sombrero). Also, planetary nebulae (e.g. the one in M46, the Ghost of Jupiter, the Ring Nebula), M1 and I think I saw the Vela Supernova remnant though am not sure, the Rosette nebula. Globulars (esp Omega Centauri which was bright and contrasty through a 13mm Ethos and through binoviewers - the view was breathtaking and three-dimensional) and M4 through binoculars.
Highlights for me through the 18" were: as said Omega Centauri, M51 which I saw the spiral arms very distinctly for the first time, M42 which was amazingly detailed large and contrasty, the Smiley Face, the Ring Nebula with two layers, the Ghost of Jupiter with the central star, Eta Carinae nebula in which I saw the nebulosity around the namesake orange Eta star for the second time (the first was at the South Pacific Star Party in New South Wales in April 2007 through a 25"), the Swan Nebula. And Saturn through the binoviewer on the 18" was fantastic! I saw three of its moons as large objects rather than mere dots.
I also managed to see the Coal Sack next to Crux, though it was not contrasty and just barely visible.
At 3am to 4am, we saw a second round of the Milky Way: a very large and long band stretching from Deneb in Cygnus at the northeast end, through Ophiuchus and Sagittarius in the central bulge, and on to Norma in the south.
I did very detailed observing of details of dark nebula and patches and knots of milky clouds through budget Nikon 7x35 binos (9 degree FOV) which was a real treat, and through 15x50 Canon IS binos. I was navigating my way round and about these for a long time through the binos.
With naked eyes, we could see very distinct regions of the central buldge of the Milky Way, including the Horse dark nebular with its legs (one of which is also known as the Pipe Nebula) pointing towards Antares, the separate Aquila rift band, and most of all, the distinct hamburger and patty dark lane running across the whole sky from the northeast through to the south. The is certainly the ultimate galaxy to view, and is a naked eye object!
Just before we left at 4am, the Milky Way got brighter and more contrasty. Though there was still a little very light haze, it was nearly as good as the best views I've had at Telok Sari. I've only had significantly better views in New South Wales as mentioned above.
I stood back for a while to take in the majestic view of the immense Milky Way, and I think had a good appreciation of where we are relative to it.
I tested and saw shadows cast from my arm to the car's body, though I'm not sure if that was due to the Milky Way or the sky glow from Singapore.
In my experience, when observing in east Johor in around March to May, its best to stay until 4am as sky conditions tend to improve from 2am to 4am. This also happened last year at Telok Sari. And 3am-6am is the best time to see the central buldge/band of the Milky Way.
We packed up and left at 4.10am, arriving at JB customs at around 5.30am.
Overall, I think this site (named "Sedili South Centauri") is a very good obs site relatively near to Singapore.
Do be very careful and take special care when driving up and down the Malaysian roads, esp at night where the lane markings may not be so obvious and sometimes a bit confusing, and you might be sleepy. I think if in doubt, keep left.
There may also be some pot holes about. Also, at a traffic junction outside JB centre, we saw a large tyre in the middle of the junction which was potentially a great hazard especially for motor cycles. Whether the tyre was dropped there accidentally or deliberately placed, I don't know. Anyway, a kind taxi driver got of his vehicle and dragged it aside. He might have saved a life! So it is a cautionary tale about driving in Johor, as I suppose anywhere else.

