Cyprus Astronomical Society

Under the Milky Way

Agapios — Thur, 03 Jul 2008 09:21:40 GMT

...and again at our favorite dam!

After last night's meeting with the C.A.S. members (the ones that showed up at least) Rolandos and myself took the road to Xyliatos for our monthly photon treatment!
Arriving on location, we were greeted by a curious dog who apparently got scared seeing us moving around in the dark with our headlamps
We set up our equipment (my new 10" dob and Rolandos's Takahashi FS102-N) and traded scopes for the night! I began taking piggyback photos with the Takahashi whilst Rolandos started scanning the areas of Leo Minor and Coma Berenice's for NGC galaxies (which he will post in detail after he sees this because I find it impossible to remember who was what unless I take notes, which I don't!).
While we were catching NGC after NGC we noticed how crowded last night was with satellites! There was a point where it became annoying and frustrating! At some points we even lost some of our dark adaptation due to these objects flying through our Field of View. And not to mention airplanes!

I will not go into too much detail target-wise but I will talk about one of the most immersive experiences a person can have. Say we are up on the dam were the skies are quite good and dark. And say you don't even own a telescope yet, just a pair of binoculars, or not even those. Take a chair, lay back, and just enjoy the unbelievable glory of the milky way. Try and grasp what it is you are seeing. You are literally standing on a piece of rock, water and gas revolving around a star on a small neighborhood of a gigantic city which is our Galaxy. To me, being able to see with my own eyes, and the ability to understand what that patchy cloud crossing the sky really is, is one of the most humbling and awe-inspiring experiences a human can have.

Now take those binoculars. Start sweeping the horizon just over the trees. In Xyliatos we are lucky because the Milky Way dives behind the trees on the mountain tops giving a breath taking view. Just imagine seeing black silhouetted trees against millions of stars filling the gaps between and over them. Continue sweeping through the patchy cloud and count the uncountable! Millions and millions of stars fill your eyes and not to mention the numerous star clusters and nebulae. The Lagoon and Trifid nebulae will almost certainly grab your attention. Cross over Saggitarius to Scutum and behold the beauty of the Swan and Eagle Nebulae. A little further left of the tea-pot's top star is the huge star cluster M22. A gigantic ball of stars. A little further up and there's M25. Jump to the right and there's M24 in all its star-filled glory.

I could go on for ever but a) I am very tired to type at the moment and b) I don't want to spoil the experience by giving you all the details. Go out there and see for yourself.

P.S. The pictures are resized and not to the fullest quality.

Forum: Deep Sky

The best eyepiece calculator EVER!

Agapios — Sat, 21 Jun 2008 06:15:38 GMT

It covers nearly every eyepiece ever made! You just add your telescope values in the top fields and it immediately calculates what any given eyepiece would mean to you!
Magnification, TFOV, exit pupil and it even automatically barlows the values with almost every barlow type ever made!

Highly recommended !

Download here

Forum: Eyepieces and accessories

C.A.S. General Meeting July 2nd

Agapios — Thur, 19 Jun 2008 08:51:31 GMT

Dear members and friends

The C.A.S. would like to invite you to a meeting to introduce new members and to register anyone who is interested to become one. At this time the C.A.S. is re-organizing its structure and operations and so it would be very helpful if you would take part with your suggestions and ideas of how you, the members or future members, want the Society to proceed. It is important that everyone attends so that we can make sure that every opinion is heard and accounted for. Amongst others, topics to be discussed are:

- The course of C.A.S. up to today.
- Evaluation of the situation at hand.
- Planning of operations for the future.

The C.A.S. aims to promote amateur astronomy on the island with any means possible. Show your support by joining us and helping us expand this hobby that we
all love! The meeting will take place on Wednesday 2 July, at 07:00pm at Strovolos town hall.

For more info

Marios Iordanou: 96 222 411
Agapios Elia: 99 986 275

Forum: Announcements

Dark frames,Flat Lights (Flats) and Offsets (Bias)

phedias — Tue, 17 Jun 2008 00:03:28 GMT

Dark frames

Digital cameras build up noise because of heat and electricity. These appear on all of your frames as tiny pixels of light, whether there is real light there or not. Some pixels are also lit up very bright red or blue as well. These are known as dead pixels. All cameras have them. There are a number of acceptable dead pixels allowed through quality control in a new camera. To remove these, we need to take dark frames.
The way it works is like this.
You take a 3 minute light. During that photo, some of the pixels in the frame will be activated by real light, some by digital noise. Put the lens cap on the telescope. Using bulb again, take a 3 minute exposure at the same ISO with the lens cap on. Later on, when you stack these together with the apropriate stacking program, the lit pixels in your darks will be identified, registered and therefore removed from every other frame, eliminating all but natural light. Thats the theory. It is important that you take these darks during or at least at the end of your imaging session, at the same temperature as your lights.
The more, the better. More than 20 is excessive though.

Forum: Digital Astrophotography methods and techniques.

Go for the aperture(me the dob owner too)

phedias — Mon, 16 Jun 2008 00:16:02 GMT

I can not believe it.
I have just ordered a new telescope.(Orion - SkyQuest XT10 Classic Dobsonian)
The price was great including a bonus accesories package(9x50 finder scope, 2" Crayford-style focuser that accepts 1.25" and 2" eyepieces,LaserMate collimator and Deep Map.)all at the fantastic price of $479.95 with no VAT because my cousin is gonna bring it to me from the US.
Now i can use it as my primary visual observation telescope all together with my SXD,VISAC and ED81S APO who they would be my imaging platform.
The only problem(i need help) is that i will have to find and use again my old sky charts!!!

http://www.optcorp.com/product.aspx?pid=1-599-63-67-11790

Forum: Telescopes

ED81S piggybacked

phedias — Sun, 15 Jun 2008 10:08:20 GMT

Guys any ideas on how to piggyback my ed81s above the VC200L?(The large accessory plate is too heavy and also side by side setup causes to many Differential Flexure problems

What accesories do i need?
Is there any chance to find them here in Cyprus?

Attached a photo of my current setup

thanks

Forum: Telescopes

Upgrading the standard Dobsonian

Agapios — Fri, 13 Jun 2008 14:32:43 GMT

Well everyone...since I got my new 10" Dobsonian I found that it too needs to be modified in order to perform to its fullest. Or at least to my liking! So I 've put together a list of things that need to be done and went out and got the parts needed.

1) Install a proper cooling fan to minimize cool down time.
2) Flock the interior of the OTA.
3) Install wheels with brakes for easier moving.
4) Install Telrad finder and 9x50 Right Angle Correct Image finder.
5) Find a proper observing chair !

Parts1,4 and 5 are already done and tested! I found a suitable fan (typical 12V pc fan) in Stephanis Electronic Sources and connected it with 9V battery cable so I can use my pair of 9V rechargeables. It slows down the fan a bit but that's ok. I've also did a good search in home furniture stores to find a stool that can fold and have the proper height and the one that better fit my needs was IKEA's 63cm folding chair (29EUR). Now as for the wheels, I went to Spanias Cyprus Engineering Stores in Salaminos Ave. and picked up 3 swivel wheels with brake worth approx 4 euro each. I am going to remove the dobsonian's rubber feet and replace them with these wheels. As for flocking, a little visit at Rainbow art studios for some black adhesive felt ("avtokolliti tsoxa") and we are set!
I will post part numbers and prices as the project goes on.
Stay tuned for the upgrades! I will finish the Rolling Dob project probably on Monday!

Forum: Telescopes

A new name for dwarf planets: Plutoids

phedias — Thur, 12 Jun 2008 23:18:57 GMT

The International Astronomical Union has chosen a new name for dwarf planets, like Pluto, that lay beyond Neptune. It's Plutoids
Pluto is finally getting its day in the sun, after being stripped of planetary status by astronomers two years ago.
1 Plutoids are celestial bodies in orbit around the Sun at a distance greater than that of Neptune
2 have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium
3 (Near-spherical) shape
4 Have not cleared the neighbourhood around their orbit.
The astronomers' action makes Pluto more important because instead of being a "puny" outer planet, Pluto is now a "prototype of a new type of fascinating objects.

ps
hydrostatic equilibrium is the condition in which pressure and gravitational forces in a star or planet are in balance. Without such balance,bodies will either collapse or expand.

Forum: General Astronomy

Film negative scan

nirbaer — Wed, 11 Jun 2008 04:40:10 GMT

Hi,
Just came back from the photo lab to find that the automatic printing machine didn't bother to print my long exps from Xyliatos because it couldn't separate between the dark frames.
Anyone knows a place (better in Nicosia) which can scan the negatives with good resolution of 2400-4000 dpi?
Either way I will try to do it myself with a digital camera setup just to compare.
Nir.

Forum: Various

Optical accessories explanation

phedias — Tue, 10 Jun 2008 18:21:50 GMT

Finder - A finder is a small telescope or aiming device with a wide field of view that is used to aim the main telescope to help find celestial objects.

Barlow - A barlow lens is a lens that multiplies the focal length of the optical system, giving more magnification and increasing focal length, but at a slower system speed. For example, a 2x barlow will make turn a 1,000mm f/8 optical system into a 2,000mm f/16 optical system.

Telecompressor A telecompressor, or reducer, is a lens assembly that shortens the length of an optical system making it faster and giving a wider field of view. For example, a 0.75x telecompressor will turn a 1,000mm f/8 optical system into a 750mm f/6 optical system.

Field Flattener - A field flattener takes a curved focal plane and makes it flat. A field flattener is a very useful accessory for astrophotography.

Coma Corrector - A coma corrector corrects for the optical aberration of coma, which gets worse near the edges of the field, in fast optical systems. It is very useful in fast Newtonian optical systems.

Minus Violet Filter - A yellow filter which filters out violet and blue light in a refractive optical system that is not perfectly corrected for color. It is very useful in achromatic doublets and other non-apochromatic refractors.

From http://www.astropix.com/GADC/SAMPLE2/SAMPLE2.HTM

Forum: Eyepieces and accessories

Summer skies at last !

Agapios — Mon, 09 Jun 2008 07:44:19 GMT

Last night Rolandos and myself strategically took the road to Xyliatos dam and arrived a bit after 23:00 giving time to the young moon to descend low enough to allow us to grab distant photons from the universe. We spent about a half hour taking pictures and allowing my new 10" to cool down. Rolandos had set up his Takahashi 22x60 bino's and I had the Hyperion Zoom ready for action. I started scanning the Milky Way for familiar friends such as M6, M7, M4, M80 and I was soon picking globular after globular on Sagittarius and Ophiuchus. M22, M14, M10, M12 and so on until Rolandos who was scanning the northern skies alerted me to M51 and how well he could see it through his bino's. I immediately turned the dob to the direction of M51 and was blown away by how clearly I could see the spirals of this majestic galaxy. It was very similar to that wonderful but very cold night at Palechori dam with the 8". The night seemed promising. Next target was NGC4565 who even though had began to descend was still easy to pick out in the Coma's chaotic galaxy cluster. The view was little short of horrible as there was very little detail visible and this made us realize that the night was fluctuating between very good and very bad. I tuned to the Milky Way again and centered the Lagoon Nebula (M8) in the Hyperion. The detail was striking! Same story with the Trifid (M20) which showed its dark dust lanes beautifully. The Swan nebula (M17) was the star of the area to me. Amazing details visible in the nebula and the "fish hook" or "swan's head" very well defined. The Eagle nebula on the other hand was another story. Upon first glance I could swear I saw the "Pillars" or the feet of the Eagle very well defined with no filter. On more careful examination using Rolandos's 11mm Nagler and UHC filter it was very hard to tell. Maybe I caught it at a very good moment of good seeing?
Some intense meteor activity caught our attention last night and by doing a bit of search I found that tomorrow (June 10) will be the peak of the Lyrid meteor shower.
Back to observing we also conducted a very interesting test between the Hyperion Zoom (set at 8mm and 12mm) and the 11mm Nagler. The selected target was M13 the great globular cluster of Hercules. The aim was to see which eyepiece better resolved the "Propeller", a very hard to see "gap" in the cluster which forms a 3-blade aircraft propeller. The Hyperion Zoom set at 12mm showed a well resolved cluster and the Propeller was visible with averted vision and very hard to see directly. Zooming in at 8mm and 125x the propeller was easier to see but still not well enough to hold steady with direct vision. The Nagler on the other hand gave the Hyperion a good smack in the butt as it displayed a fine sight and the required formation of the 3-blade propeller was easily held with direct vision.

The night ended with observing the giant Jupiter. I was pleasantly surprised at the performance of my new scope. I had never seen so much detail visually with my super-charged 8". Cloud belts, satellite shadows and festoons were easy for the 10" and even though the Hyperion Zoom only climbs up to 125x with no barlow the view was incredible. Boosting up the magnification with Rolandos's barlow and 7.5mm Takahashi LE eyepiece the view was degraded. We stepped back a bit and switched the eyepiece to the 11mm Nagler and enjoyed a fantastic view of the gas giant!

Well thats about it, we departed around 2:45 and considering the 3-hour sleep I'm still typing... must be the Snickers bar

Forum: Deep Sky

GREEK FORUM - ELLHNIKO FORUM

astronomaki — Sat, 07 Jun 2008 16:40:03 GMT

English:
For those who are interested there is an independent greek astronomy forum on:
http://astronomy.com.cy/

Greek:
Gia osous endiaferonte yparxei kai elliniko forum sto:
http://astronomy.com.cy/

Forum: Announcements

Celestron upClose 10x50

Agapios — Sat, 07 Jun 2008 07:35:32 GMT

Celestron 10x50 Binoculars
Magnification 10x
Exit Pupil 5mm
Angular Field of View 7 degrees
BK7 glass
Carrying case.

Excellent condition - Like new -

50 EYR

Forum: For Sale

The perfect summer challenge ?

Agapios — Fri, 06 Jun 2008 07:27:22 GMT

... the Ring Nebula's central star!

You all know (you should!) Messier 57 / Ring Nebula in Lyra.

Central star

A planetary nebula is formed after a medium or low mass star, such as the Sun, has exhausted the hydrogen fuel at its core. At this point the star changes form to achieve a new equilibrium condition in which it can burn helium fuel. By so doing, the outer layers expand and the star becomes a red giant. After about a billion years, temperature instabilities develop from the fusion reactions inside the star, causing the outer atmosphere to be ejected in a series of energetic pulses. This expanding gaseous shell forms a spherical nebula that is illuminated by ultraviolet energy from the star at its center.

Within the past two thousand years, the star at the center of the nebula left the asymptotic giant branch after exhausting its supply of hydrogen fuel. This means it is no longer producing energy through nuclear fusion. It is now approaching the final stage of its evolutionary life where it begins to steadily cool down as a compact white dwarf. This star now consists primarily of carbon and oxygen, with a thin outer envelope of lighter elements. It has about 0.612 solar masses and a surface temperature of 125,00000 K. Though currently 200 times as luminous as the Sun, it has a visual magnitude of only 15.75.

Well the visual magnitude is actually around 15.1 and presents a real challenge for 8-10 inch telescopes although people report having seen it with smaller instruments.
Clear, steady skies are required with the object preferably at its maximum height.
So... who's up for it? (Rolandos are you listening?)

Forum: Deep Sky

Two Of The Milky Way's Spiral Arms Go Missing

phedias — Thur, 05 Jun 2008 18:57:53 GMT

For decades, astronomers have been blind to what our galaxy, the Milky Way, really looks like. After all, we sit in the midst of it and can't step outside for a bird's eye view.
Using infrared images from NASA's Spitzer Space Telescope, scientists have discovered that the Milky Way's elegant spiral structure is dominated by just two arms wrapping off the ends of a central bar of stars. Previously, our galaxy was thought to possess four major arms.
An artist's concept of the structure of our two-armed Milky Way is online at http://www.nasa.gov/mission_pages/spitzer/multimedia/20080603a.html.

Forum: Various