I Detect exoplanets by yourself with the cheapest equipment

[alberto91]

Hi guys,

I detected my first exoplanet (hd 189733 b) and made a video about it showing step by step how I did it. I thought it could be useful for the people interested in the topic or already starting with transit photometry.

The star has an apparent magnitude of 7.7 and the exoplanet produces a drop of 2.8% during almost 2 hours.

I used a tele-photo lens (the Pentacon 135 mm f 2.8), a CMOS camera (ZWO ASI 120 MM) and an equatorial mount (Skywatcher EQ3-2)

I also have a dual-axis motor drive, but a simple one that only controls the right ascension would be enough.

I bought most of the items second-hand from Ebay and I spent around 300 euros.

To set up the tele-photo lens and the camera I have a couple of guide rings and in order to focus the tele-photo lens, I have to separate it 33 mm from the camera by using for example 2 M42 extension rings, one of them 28 mm long and the other one 5 mm.

Now, the steps to detect the exoplanet are the following:

1. Find out when is the exoplanet going to transit the star with the Exoplanet Transit Database.
2. With a program called SharpCap, take for example 5-second exposures with a gain of 1 for 3 hours.
3. Once the transit has finished, with a program called ‘AstroImageJ’ open all the images, select the target star and for example a couple of reference stars, and perform multi-aperture photometry to detect the light curve.

I think it is better explained with a video:

 

[Drakkith]

Very nice. I managed to image a transit of Tres-3b a number of years ago using an 8-inch telescope.

 

[alberto91]

Very nice. I managed to image a transit of Tres-3b a number of years ago using an 8-inch telescope.

Thanks ! wow that is awesome :)

 

[Bandersnatch]

Very nice. I managed to image a transit of Tres-3b a number of years ago using an 8-inch telescope.

Care to describe your setup and methods, and how they differed (if at all) from Alberto's?

 

[Drakkith]

Care to describe your setup and methods, and how they differed (if at all) from Alberto's?

Major equipment:
8-inch telescope at F/8
Atlas EQ-G Mount
SBIG-2000XM camera

My method was essentially the same as Alberto's. Find the target star, take an exposure very X amount of seconds such that neither my target nor reference stars were overexposed, and then process them. Align all the images and find the average of several reference stars in the FOV for each exposure and then compare that value to the measured value of your target. Do this for each frame and then plot the results. Luckily most of the processing was a semi-automated process with the software I was using.

 

[alberto91]

Major equipment:
8-inch telescope at F/8
Atlas EQ-G Mount
SBIG-2000XM camera

My method was essentially the same as Alberto's. Find the target star, take an exposure very X amount of seconds such that neither my target nor reference stars were overexposed, and then process them. Align all the images and find the average of several reference stars in the FOV for each exposure and then compare that value to the measured value of your target. Do this for each frame and then plot the results. Luckily most of the processing was a semi-automated process with the software I was using.

Indeed! I'm glad more people are interested in this :)