Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.



New Members
  • Content Count

  • Joined

  • Last visited

Community Reputation

11 Good

About alberto91

  • Rank
  1. Hi, Sorry may I ask you another doubt please? It is about the ADU. Do I need to ideally get around 30,000 in ADU for any given star, regardless of its apparent magnitude? For hd 189733 (8 mag) I got 30,000 with exposure 5s and gain 1, but now I'm trying a 12th mag star and I get the 30,000 with exposure 30s and gain 30 (out of 100), for example. With this 12th mag star, when I use exposure 30s and gain 10, I get an ADU of 10,000 only. Is 10,000 enough to detect transits or should I always try to get at least 30,000 ADU? The variation in brightness I'm getting with this 12th mag seems to be right. The dip of the transit would be 4%. Thanks in advance. Regards.
  2. Great target ! mm yes, I guess it is a matter of try/fail to find the right exposure/gain to avoid over saturation I checked the ETD and saw that wasp 33 is 8.3 magnitude and 1.5 % dip so... I would increase the exposure a bit, to for example 10, and greatly reduce the gain, to for example, 3 I'm sure the experts in the forum can give you better advices !
  3. Thanks everybody for the kind words! I really appreciate them And thanks for the tips! Yes, I would go for the brightest stars and the dippest drops in brightness.
  4. 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: Find out when is the exoplanet going to transit the star with the Exoplanet Transit Database. With a program called SharpCap, take for example 5-second exposures with a gain of 1 for 3 hours. 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: https://www.youtube.com/watch?list=PL3RiFKfZj3pv1ZqpFxuZinoGtUGEOankw&v=XHCppdWYs6w
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.