Quote Originally Posted by Dragan View Post
Using data obtained from the Yerkes Observatory 40” refractor, Hubble knew R Mon to be a variable star and 2261 belonged to a family of nebulae & stars (T Tauri stars) that had pecularities in common with other variable nebula such as, NGC2245, NGC1555 (Hinds Variable), NGC6729 and even NGC7662, the Blue Snowball! (though I haven't done any research on NGC7662, this paper suggests that Hubble believed it to be variable. Does anyone have any information on this?)
Ok, so it was a little late into the night when I wrote the above but it did get me thinking.

As I was reading through some papers researching for this weeks OOTW, I came across Hubbles paper from 1916. In it, he mentions that NGC7662 is variable, not unlike Hubbles Variable Nebula, NGC2261. Well, being late into the night, I read that as if the nebula itself varies, NOT the central star. Looking further into it this morning, I realized that I misunderstood and its the star that is variable and it varies by as much as 3 magnitudes over a period of 28 days. (As proposed in EE Barnards paper published in 1908)

But, what I would like to ask the group is this: Could this lend to some variability into the nebula itself? I understand that the mechanics behind 2261's variability is different than my suggestion. 2261 is a reflection nebula and its changes are basically a play on light. But a planetary is glowing excited gas. Couldn't a variation in its central star's energy output also lend itself to a variation in those excited gases? Could a PN with a variable star be itself variable?

Just some curiosity indoors as a snow storm rages outdoors!