ALP Stargazing Report



March 12-13, 2005

Text and Images by  Jett Aguilar




James, Jun Embuido and I made our rendezvous at the Shell Alabang gas station at around 5:30 pm.  We hit the South Luzon Expressway in a 3-car convoy at about 6 pm and after a safe and thankfully uneventful trip arrived at the Caliraya Hilltop resort at 7:30 pm.  We then had a quick simple dinner before checking in for a room.  On the way out of the hotel we met Allen who just arrived after participating in a punishing martial arts competition (talk about dedication to astronomy!).

The sky at this time looked dark and promising and we wasted no time in setting up. James and I set up our astrophotography equipment right on the bridge over the fishing pond to prevent a repeat of our November mishap when we had trouble polar aligning our scope.  Polaris was easily sighted and both of us were ready after about 30 mins.

I started by imaging the large but dim Pinwheel galaxy 050312m101_jett.jpg (200779 bytes)(M 101) in Ursa Major.  I took a series of 2.5-3.5 min exposures at ASA 1600 using my Canon Digital Rebel at prime focus on my C8 (6.3 focal reducer attached).  The spiral arms were barely discernible even with the 3 min exposures.  I believed that sky transparency was  not very good at the time which sort of negated the advantage of dark skies.  Heavy dewing also added to our difficulty and I even had to wipe my corrector plate during the early morning since it had been completely dewed out.  Despite this, I was able to collect 12 images which I stacked in Maxim DL.  I also took a few "dark images" which I subtracted from the actual M 101 images in Photoshop 7 before stacking. 

At around this time Jun pointed out a bright fuzzy object seen on his binoculars low in the Southern horizon.  I jokingly told him that he might have discovered comet "Embuido" but James dashed his hopes of eternal fame by pointing out that it is the  spectacular globular cluster in Centaurus   Omega Centauri.  We spent a few minutes admiring it via binoculars and also with naked eyes.

050312m81_m82_jett.jpg (365404 bytes)After M 101, I turned my attention to M 81 & M 82 but was able to take only 1 shot before the sky suddenly clouded out at about 1:00 am. James and I waited out the clouds by taking a very long coffee break  until 3:30 am when the sky partially opened up again.  Vega was already high up and I took the opportunity to image M 57, the ring nebula.  Dewing was still bad and I had some trouble focusing my scope.  Nevertheless I still took several 3 minute exposures of m57. 

The blue ring with a reddish rim could be seen with a hint of a central star but not much else.  The loss in detail and fuzzy appearance could be the result of poor focusing, poor transparency and insufficient exposure time.  I'll try to get a better image next time.

That was my last image before I called it a "night" and 050312m57_jett.jpg (149134 bytes)James and I had the obligatory "group" picture.  Overall I was not very happy with the results of my imaging session and I hope to improve on my images next time.  However, I think it was also a productive evening despite the poor conditions since James and I were still able to do our imaging.  Lastly, our trip demonstrated the unreliability of weather predictions especially in a very dynamic place like  Caliraya.  The Accuweather prediction based on the Lumot weather station predicted rains and > 90% cloud cover all throughout the night which was fortunately not true.  I'm looking forward to going back again this April and would like to invite all the other ALPers who were not able to come to join us this time.


For Comments

2003, 2004, 2005  Astronomical League of the Philippines Inc.