Nebulae- Astronomy (nBSG minor spoiler)

Post by **Vympel** » 2006-11-20 02:02am

Quick question- in a recent episode of Battlestar Galactica, the Thirteenth Tribe used the Lion's Head Nebula as a waypoint to show the way to Earth, and this "Lion's Head" (with a "blinking eye"- i.e. pulsar) was identified in the Scroll of Pythia (a religious text) and used by the Colonials on their way to Earth- 3,000 years later.

Now, a nebula is just a cloud of gas, right? Is it plausible that the Nebula would still be a "Lion's Head" after thousands of years have passed? Do the shapes of nebula change appreciably in space over that period of time?

Junghalli · Post by **Junghalli** » 2006-11-20 02:33am

The Veil Nebula (a real life supernova remnant) is estimated to be between 5 and 8,000 years and the Crab Nebula (another one) is around 7,000 years old (the supernova was recorded by Chinese astronomers in 1054 and it's 6,000 light years away). So yes, a supernova remnant can definitely last 3,000 years.

Since a supernova remnant consists of gas blasted off the star by the supernova it is expanding, and would gradually change shape. By how much over 3,000 years I'm not sure. But if this Scroll of Pithia recorded its position in the sky it should be fairly easy to find even if it's not recognizable (once you've compensated for 3,000 years of stellar drift). Luminous nebulae make pretty obvious landmarks.

Durandal · Post by **Durandal** » 2006-11-20 04:13am

3,000 years is a pretty tiny amount of time on the galactic scale. We can still easily identify constellations that were identified centuries ago, for example.

dragon · Post by **dragon** » 2006-11-20 11:30am

Ok missed that episode but wouldn't the nebula change its shape depending on the angle you viewed it from. So if they were able to see the horse head nebula resembing a horse head than wouldn;t that mean they would have to be looking at it from the same angle as us.

CmdrWilkens · Post by **CmdrWilkens** » 2006-11-20 12:04pm

dragon wrote:Ok missed that episode but wouldn't the nebula change its shape depending on the angle you viewed it from. So if they were able to see the horse head nebula resembing a horse head than wouldn;t that mean they would have to be looking at it from the same angle as us.

Thus the usefulness as a navigational aid as it would force you to orient yourselves along the right axis of advance with a certain amount of wiggle room.

dragon · Post by **dragon** » 2006-11-20 01:31pm

CmdrWilkens wrote:
dragon wrote:Ok missed that episode but wouldn't the nebula change its shape depending on the angle you viewed it from. So if they were able to see the horse head nebula resembing a horse head than wouldn;t that mean they would have to be looking at it from the same angle as us.
Thus the usefulness as a navigational aid as it would force you to orient yourselves along the right axis of advance with a certain amount of wiggle room.

Same with using star patterns as a nav aid.

Post by **Vympel** » 2006-11-21 02:51am

That problem would be minimized in nBSG because they had a good idea of the way the Thirteenth Tribe had come already from their previous information- they knew the location of Kobol, after all.

Anyway, question answered, thanks guys.