Astronomy Picture of the Day 10-03-02

NASA ^ | 10-03-02 | Robert Nemiroff and Jerry Bonnell

[petuniasevan]

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2002 October 3

V838 Mon: Mystery Star
Credit: Lisa Crause (Univ. Cape Town), Warrick Lawson (Australian Defence Force Academy)

Explanation: A leading candidate for the most mysterious star found in recent times is variable star V838 Monocerotis. At a distance of about 8,000 light-years, V838 Mon was discovered to be in outburst in January of this year. Initially thought to be a familiar type of classical nova, astronomers quickly realized that instead, V838 Mon may be a totally new addition to the astronomical zoo. Observations indicate that the erupting star transformed itself over a period of months from a small under-luminous star a little hotter than the Sun, to a highly-luminous, cool supergiant star undergoing rapid and complex brightness changes. The transformation defies the conventional understanding of stellar life cycles. A most notable feature of V838 Mon is the "expanding" nebula which now appears to surround it. Seen above in two separate images from the South African Astronomical Observatory's 1 meter telescope, the nebula is probably a light echo from shells of formerly unseen material lost by the star during its previous evolution. Light-years in diameter, the shells progressively reflect the light from V838 Mon's outbursts, providing an opportunity to look back at the history of this remarkable star's behaviour.

[petuniasevan]

Looks like this star serves as a little "teaser" to show us we don't really know as much about the universe as we think we do.

V4332 Sgr is a star which showed a similar sudden change to red giant status in 1995.

[petuniasevan]

[sleavelessinseattle]

Now SEE! If I ran a powerful Hi Tech civilization and we needed some gigawatts of power, I'd cycle the sun through some different energy states as needed to get the fusion boost and maybe heavier elements I wanted...The two sci fi books "Forge of God" and "Anvil of Stars" deal with the concept of inconceivably advanced ET civilizations that use solar systems like billiard tables and create genetically modified species to act as intermediaries with new star faring civilizations moving around the galaxy...Larry Niven's great assertion that "Any sufficiently advanced technology may appear indistinguishable from "magic" to less advanced cultures." might apply here.

These odd systems may simply be massive public works projects...who knows?

[glock rocks]

hmmmm. assuming a time linear universe?

highly recommend Robert Silverberg's short story "In Entropy's Jaws."

[MeekOneGOP]

[BossyRoofer]

Great lesson! Good picture, APOD the place to be!