AiM - Astronomy and internet in Münster
(Astronomy 2.0)

Goldilocks Variable, a MIRA star in Dumbbell Nebula M27

Goldilocks or NSV 24959 is a variable star of type Mira. In 2016, a group of students from the Pascal Gymnasium in Münster published an article in the BAV newsletter Nr. 2 (ISSN 0405-5497) about the change cycle. Based on our own observations and evaluations of external observations from 18 years, we predict a period of 214 days. 

Now we want to test our prediction with new daily measurements.

Dumbbell Nebula (M27)


The prediction above was generated by transforming the measurements by a given period to align in a signle cycle of the star. For the original period the cycles aligned for a test period of 214 days with an error margin of 1 day in the positive and negative direction. The transformed diagrams used for the original projections are displayed below:

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Theses measurements are aligned around a date in mid-October 2014. Projecting these dates forward, we get a predicted cycle for our new daily measurements. These diagrams are displayed below:

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The diagrams are centred around the end of May 2020. So far (mid-May 2020) our cycle predicted by assuming a period of 214 days seems to match our new observations. A period of 214 days give or take one day predicts the next increase in brightness between 19 July 2020 and 8 August 2020.