My first variable star measurement

[Dave Smith]

Recently I produced an image of the variable star Algol winking. It was just a fun animation but not at all scientifically accurate. So I thought I might try some proper photometry with help from publications on the BAA website. This is one of the recommended stars for beginners. EG Cep. I found the star using SGPro and took a 30s sub every 5 minutes while it was clear which last night was for about 7 hours. Unfortunately it was just getting to the interesting bit as the cloud and mist rolled in. There was also a near full Moon which didn't help. I don't have the correct V-type photometric filter so used a green filter instead which means the magnitude values will be out. This was meant as a trial run to help me decide whether I want to pursue this further and whether to purchase the proper filters so that useful scientific measurements can be taken. I certainly found this fascinating especially as I could see the graph developing during data collection. This was done with my Megrez 90 refractor with 0.8 x FR/FF and Atik 460EX CCD camera. The photometry was carried out using MaximDL.

Any further advice from the experts very welcome.

Dave

[JeremyS]

Congratulations, Dave. Looks like a decent result first time out. I don't think I achieved that!

The quoted period of EG Cep is 0.54 days or ~13 hours. Looks as if you caught half a cycle. Well done!

All the best,

Jeremy

[Dave Smith]

Many thanks Jeremy. To be fair this wasn't strictly my first time. Some years ago I did the OU practical astronomy course "Observing the Universe" which included measuring an eclipsing binary as a team member. It is the first time with my own gear and alone.

It's a pity I didn't get the next part of the cycle which I presume was the main eclipse.

Dave

[dokeeffe]

Well done that looks great. Its amazing how much the magnitude changes over a short time frame.

[Dave Smith]

13 minutes ago, dokeeffe said:

Well done that looks great. Its amazing how much the magnitude changes over a short time frame.

Thank you. The two stars involved are really close together and virtually touching so their orbit time is short.

Dave

[laudropb]

Very nice results Dave. Certainly a very promising start.

[Dave Smith]

Thank you Laudropb.

Dave

[particleastro]

Cool!

 

This was my third year university project.  Our observatory was next to the student union, I remember having to request they turn off the huge floodlights on the front of the building in advance so I could take measurements.  And the go TO the student union when I was done.

 

J

[Dave Smith]

5 hours ago, particleastro said:

Cool!

 

This was my third year university project.  Our observatory was next to the student union, I remember having to request they turn off the huge floodlights on the front of the building in advance so I could take measurements.  And the go TO the student union when I was done.

 

J

Thanks J. Presumably you did much more than my effort? Measuring the period and calculating the mass ratio of the stars? Was it this star or another similar? Was your main subject astronomy or was that part of a course?

Dave

[DHEB]

Congratulations, really well done!

[Dave Smith]

Thank you Cinco.

Dave