Um pequeno teste, com muita turbulência numa noite com algumas nuvens altas. Sem flats nem grandes artifícios, apenas uma passagem no Registax 6.

After some maintenance on the weekend, last night I grabbed some frames from M13 with my setup to try out the collimation. It’s only 20 minutes (click on image for full size) but it’s good enough. The sky was very hazy, with thin clouds and lots of dust from Sahara and ashes from the many fires that have stormed Portugal recently, but the purpose was to see the shape of the stars, and that was done.

M13, also know as the Hercules Cluster is a globular cluster of stars, composed by a several hundred thousand stars bound together by gravity, located 25100 light-years from Earth. At the telescope it appears like a small puff of cotton, with the core appearing to untrained eyes like some dirt on the glass, but with time it resolves nicely, and it’s a beautiful object to see. It can be seen with the naked eye from places with very dark sky, and in Portugal I’ve been lucky enough to see it twice from Alentejo.

HAT-P12-b captured on the night of June 15, 2010, from the UFObservatory, Portugal, under a Full Moon and hazy skies.

This capture was the first real test of the complete robotic system that’s been under construction and has just become operational at UFObservatory, a robotic multi-pier observatory. The session was done remotely (but just for a few dozen meters) by me and my friend João Gregório, that happens to be the first amateur to produce a light curve for this exoplanet. Another friend was capturing pretty pictures from his living room, more than 100Km away.

No Filter
Celestron C8 and Alan Gee Telecompressor + QSI 504
William Optics ZenithStar 66mm + Atik 16IC
Losmandy G11 Gemini

Captured last night, at Astrovide 2009, with my little TMB 80 and a Atik 314L, guided by a Skywatcher 70/700 with a Atik 16ICS loaned by Rui Tripa. Everything was monted on a Skywatcher HEQ5 Pro.

Exposures:

• Luminance: 150 minutes (6x300s + 12x600s)
• Red: 30 minutes (6x300s binned 2×2)
• Green: 30 minutes (6x300s binned 2×2)
• Blue: 42 minutes (6x420s) binned 2×2)

No darks, no flats.

This dull image was captured July 5, 2009 at 22h31m58s UT, and is the first image obtained remotely from the observatory. The star is Cor Caroli, the brightest in the constellation Canes Venatici, a small patch of sky near Ursa Major. The star also know an Alpha Canum Venaticorum, was named Cor Caroli Regis Martyris by Sir Charles Scarborough in honour of Charles I.

For this first test, I connected remotely to the observatory’s computers and commanded the roof to open, unparked the mount, pointed at the target and took test exposures, while a friend was on location reporting on the events and making sure that no catastrophic event would ruin the evening that was a complete success. The weather wasn’t great, with some clouds rolling in, but in the 45 minutes the roof was open I managed to point the telescope at 4 targets, and somewhat successfully image the sky.

I got a short exposure of M3, the globular cluster in the constellation Boötes before the clouds rolled in:

Mizar, one of the components of the famous double in Ursa Major:

And the last, probably the worst image of M51 that I ever made, but the one that I will keep for a long time:

The test was a success, and a major milestone was completed in our little observatory. We expect to be fully operational in a few months, and by the winter the telescopes should be looking at the sky every clear night. With a little luck, it’s going to be one of the best Christmas presents ever !

A few months back while searching for solutions to automate the observatory’s roof, I came across a small shop on Bulgary that sells USB and Serial relay boards, in various configurations. At the time I bought a couple of USB One Channel Relay Units and they sitted around for a while, while I finished some other small projects.

Today I finished the assembly of the board. I got a small plastic box, that turned out to be a tiny bit smaller that it should, forcing me to chop off a few millimeters at the corners of the PCB, cut a slot on one end for the USB port and power cable, and got a cheap triple extension cord from the local hardware store to make the thing useful.

The final result was this, with a unused board on the side:

To control it, I made a small C# application (.NET 2.0, Windows only), that presents a simple form with a button, and can be controlled from the command line. You can download it here (zip, 5Kb) if it’s useful for something.

To change the COM Port, you should edit HKEY_CURRENT_USER\Software\SigmaPower\COMPort on your registry (the key is created on first run)

To use it from the command line, you should pass it a single parameter: “ON” / “OFF”, or “1″ / “0″. Ex:

c:bin>SigmaPower ON

This one should be installed on the observatory by tomorrow!

O Hubblecast é um videocast produzido pela ESA e pela NASA, com novidades e imagens do Telescópio Espacial Hubble. O video é uma produção de alta qualidade de divulgação cientifica, e já há algum tempo que o acompanho.
Hoje decidi traduzir o Episódio 28 para português, e construir legendas para o filme, para as pessoas que possam ter dificuldade em perceber inglês.

As legendas estão em formato SRT e devem funcionar sem problemas (na verdade, no meu Mac o Quicktime com o Perian não conseguiu ler as legendas) num qualquer leitor multimédia que suporte este formato. O VLC é gratuito, Open Source, funciona em Linux, Windows, e Mac OS X, e reproduz sem problemas o filme, e as legendas.

Links

• As legendas: heic0907a.srt 16Kb
• Os filmes: em vários formatos do site do Hubble

Via kottke the Milky Way Transit Authority map by Samuel Arbesman.

From Cosmic Variance a note about a paper from Bob McElrath that appeared on arXiv. The paper is too technical for me, but a new perspective on something that puzzles scientists for so long is always a good thing…