Sunday, September 25, 2011

Urban Astronomy

with my Astromates observing at an Urban location
Dark skies are best for doing astronomy. With limited light pollution and air pollution, you can bring out the beauty of the universe through a star studded sky. Now that I am based in Quezon City, I no longer have the advantage of observing in sites with clear dark skies. However, there is still a lot observational astronomy that can be done in urban locations.

There are some periods & locations in urban sites where you can observe depending on the sky quality at a given time. Dr. Jesus Rodrigo Torres, professor of astronomy at RTU and member of the IAU, designed an urban astronomy scale (being used by NASA) for which you can categorize the night sky.

He categorized the sky conditions as follows:
I. Best sky quality with the lights from the residential and commercial centers subdued; the air is satisfactorily transparent; a hint of the Milky Way can be glimpsed in the Scorpius-Sagittarius region; moonless and cloudless.

II. Good sky quality with the air being satisfactorily transparent, but lights in commercial and residential areas still on; moonless and cloudless.

III. Moderately poor sky quality with high or fast-moving clouds revealing patches of transparent sky, but light in commercial and residential centers is subdued; Moon in crescent phase.

IV. Poor sky quality with high or fast-moving clouds; lights in commercial and residential centers are still on; Moon in crescent phase.

V. Bad sky quality with haze; lights in commercial and residential centers still on; limiting magnitude is +3.0; Moon in quarter phase.

VI. Very bad sky quality with haze or clouds almost covering the entire sky; heavy air and light pollution; Moon first quarter or bigger; limiting magnitude ranging from +2 and +3

Under each category there are still a number of things you can observe. For a category VI, you can still observe the moon, planets and bright single or double stars.

We were just observing last night till dawn under category IV-V skies. We were able to observe Jupiter, the Orion Nebula, Pleiades, Draco, Sirius and also the thin waning crescent moon (28 day old moon). We observed using a Travel Scope 70, and a 10x50 UpClose binoculars.

Thin Waning Crescent Moon. Photo Taken via afocal method with a Travel Scope 70 (10mm eyepiece) and Sony DSC-W350.Photo by Lieza Crisostomo.

Tuesday, September 20, 2011

Travel Scope 70 Review

I recently acquired a Celestron Travel Scope 70 from Cutting Edge as an early Christmas gift from my father. It was one of three affordable grab-and-go scopes sold - the other being the Firstscope and the Travel Scope 50 (both less 4k; and the scope at 4470). The Travel Scope 50 had bad reviews so I avoided it. I wanted to get the C90 Maksutov but it was out of the available budget range..hehe. This will be my 2nd refractor, the other being a Tasco 2-inch(?).

The Travel Scope series portable telescope is specially designed for traveling. Both the 50 and 70 are compact refractors suitable for terrestrial and astronomical observing.

The TS 70 has a 70mm aperture in a compact body (17 inches long). It comes with a full size photographic tripod, a 5x24 finderscope, two eyepieces (20mm and 10mm - nothing special) and custom backpack for traveling. It also comes with TheSky x First Light edition. The scope only weighs 3.3lbs making it very easy to carry around. Also, the optics are fully coated. The assembly was quite easy too, I didn't even use the manual (well, that could just be experience speaking).

The tripod was quite shifty though. Try touching the focusing knob while viewing a bright star and it will dance to your touch. It's more stable when collapsed to it's lowest height - more like a table-top scope like the Firstscope. Also, it seems like the tripod couldn't hold the whole weight when pointed towards the zenith. I think the tripod is the biggest let-down. Anyways, you can't expect much from the mount for the price.

I wasn't able to observe much during my first attempt due to poor observing conditions but I was able to view clearly the Double-Double in Lyra, and low-magnitude stars in the tail of Scorpius in a wide field of view. On my second attempt, I had Jupiter in sight and was amazed at the amount of detail I could see. I could make out the bands of Jupiter and saw all 4 Galilean moons. Online reviews say they can see the Trapezium with it, I have yet to test that for myself.

Oh, yeah! It isn't written down in the features but the focuser on the TS 70 has a T-thread on it for SLRs via T-rings. I wonder why this key feature is not mentioned? Just make sure to change the tripod before attempting to attach a weighty SLR.

Although the magnifications attainable (with the given eyepiece) are lesser than the Travel Scope 50 (especially since it comes with a Barlow lens), the TS 70 has a higher aperture for higher maximum useful magnification. Therefore, upgrade your eyepiece and you get better images.

Basically, you can just replace the eyepiece and the tripod with better ones and you get a great scope at a low price! ^_^

Monday, September 12, 2011

Philippine Planetariums

When I was in grade 3 at Baguio city, I remember the mobile planetarium that visited our school. This is one of the thing that fostered my interest for astronomy. Planetarium shows are wonderful, for kids and adults alike. Here is a list of the planetarium's I know of in the Philippines (except for the mobile one whose name I could not recall):

The Manila Planetarium/National Museum Planetarium

PAGASA Planetarium

SkyXplore SpaceDome Planetarium

Digistar Planetarium

Mayon Planetarium and Science Park

Saturday, September 10, 2011

My Astronomy Classmates at the Planetarium

After our class in RTU, we headed to MOA to visit the Planetarium at the Nido Science Discovery Center. We were supposed to go to Binangonan, Rizal for a stargazing session but due to poor weather conditions we had to cancel. My fellow astronomy classmates in RTU's graduate school were with me in watching the planetarium show and checking out the exhibits. We intended to see the 'Cosmic Safari' and 'The Dawn of the Space Age' in relation to our Life in the Universe class but were only able to see the latter. We were joined by a group of small children (in a field-trip of some sort) who were actively making comments on the planetarium show. We explored the rest of the exhibits after the planetarium show and had our picture taken beside the Sesame Street characters that was part of another planetarium show (They have many other shows, perhaps I'll make a separate post for the planetarium).