SEMIREGULAR.COM - OBSERVING VARIABLE STARS

Sisältö

Työkalut

Muuttujaluokat

Yhteisö

For members only

Aseta kieli

Vierailut

28.12.2008 milu
28.12.2008 milu
28.12.2008 milu
02.01.2009 milu

06.01.2009 (guest)
06.01.2009 (guest)
06.01.2009 (guest)

INFOWIKI System - PROTOTYPE - Takaisin WIKI indeksin etusivulle

Artikkeli kuuluu kategoriaan : Blogs

Mika Luostarinen - Gallery

History | Gallery | Instruments

In this page you can see some photos that I have taken. Normally, I do not spend my observing time doing astrophotography but occasionally I shoot some more-or-less interesting targets or targets that just happen to be close to my variable stars ...

The camera I am using is SBIG ST402ME. It is a monochrome camera that works very well for photometric work (it's NABG camera, quite linear and photometric filters are available). Even if the camera is monochrome it is possible to take color pictures but I never do that even if I do have the LRGB color filters. Sorry, but in this page you can only see "black and white" pictures.

Some pictures show some granularity in them. This is because I do not heavily process the images I shoot. Usually I just subtract the dark-frame and I'm done.

One of the telescopes I use for observing, the Meade 10 inch SCT pictured here with the SBIG ST402ME CCD-camera, f3.3 focal reducer and HEQ-5 Pro Goto mount.

ABOVE: The planetary nebula M27 (The Dumbell Nebula) in the constellation Vulpecula is shown in this picture. Image was taken with the Scopos 66mm ED/APO with SBIG ST402ME CCD-camera. Exposure time was 30 seconds (unguided). Mount was HEQ-5 PRO Goto mount. This image was taken in the middle of light polluted Espoo in July 2007 when the sky is very bright also during night time. Image has not been processed or manipulated. Only dark-frame has been subtracted.

ABOVE: Same nebula M27 taken with William Optics FLT110 APO refractor. Exposure time was 2 minutes. Mount was HEQ-5 PRO Goto mount. This image was taken in the middle of light polluted Espoo in July 2008.

ABOVE: Same target than above (The M27 -The Dumbell Nebula). This was taken with Meade 10 inch SCT telescope with f3.3 focal reducer. Exposure time 1 minute. The moon was almost full when this was taken (24.9.2007). The corner areas of the image are not that good due to vignetting caused by the focal reducer.

ABOVE: This is another planetary nebula M57 in the constellation of Lyra (the small white ring in the lower middle part of the image).

Picture was taken with the Scopos 66mm ED/APO with SBIG ST402ME CCD-camera. Exposure time was 40 seconds (unguided). Mount was HEQ-5 PRO Goto mount. This image was taken in Artjarvi in the Ursa observatory in July 2007. Image has not been processed or manipulated. Only dark-frame has been subtracted.

ABOVE: This is M71 in the constellation of Sagitta (middle left). M71 is a star cluster that is usually classified as a globular cluster. However, the type of this object has not been verified. This is a difficult target even for bigger telescopes. Picture was taken with the Scopos 66mm ED/APO with SBIG ST402ME CCD-camera. Exposure time was 30 seconds (unguided). Mount was HEQ-5 PRO Goto mount. This image was taken in Espoo during july 2007 in less than optimal sky conditions (haze and bright summer sky). Image has not been processed or manipulated. Only dark-frame has been subtracted.

ABOVE: This is V LYRAE in the constellation of Lyra. V Lyrae is the bright star slighly off-center to upper left in the image. The picture was taken with the Scopos 66mm ED/APO with SBIG ST402ME CCD-camera. Exposure time was only 20 seconds (unguided). Mount was HEQ-5 PRO Goto mount. This image was taken in Espoo during july 2007 in less than optimal sky conditions (haze and bright summer sky). Image has not been processed or manipulated. Only dark-frame has been subtracted.

Remember M57 above ? Well, I was on my way to this target on that night and the M57 just happened to be close to this so I shot M57 too .. but this star was one of my real targets that night. The star looks very bright in this image due to reason that I used no filter. I also took other images with filters but the star is a lot dimmer in those ones and you would have a hard time finding it in the picture so I would need to mark it for you but I was lazy .. so, I just selected the photo with the bright star in it.. ok :)

Fine, but what is V Lyrae (or V LYR for short) anyways? It's a variable star. Below you can see rather recent lightcurve of V LYR. Normally you do not observe Mira type of variables with CCD camera that often but this time I decided to test the new equipment so I shot some LPV (long period variables) with the new camera.

ABOVE: Lightcurve of V LYR variable star. You can see that the star brightens up to 9-10 magnitudes and when it is dimming it dives down to 14 magnitudes. You can find more info of V LYRAE from here.

I took timeseries of cataclysmic variable IP PEG on 12th of October 2007. The period is 3.8 hours for this target. The star is marked with white lines in the two pictures below. The telescope was 6 inch Maksutov-Cassegrain with f3.3 focal reducer. Camera was SBIG ST402ME. Exposure time 20 seconds, unguided. Unfiltered. The total timeseries contains 250 images.

The pictures below are raw. Dark frame or flats have not been reduced for these.

ABOVE: IP PEG as visible. Brightness is about 14.6 magnitudes.

ABOVE: IP PEG as not visible. Brightness below 15.4 magnitudes.

Edit page