M74 - Galaxy in Pisces

The Messier Ten Minute Challenge

M74 - Galaxy in Pisces

Messier 74 (NGC 628) is a prime example of a spiral galaxy but with
its low surface brightness it is one of the more difficult objects in
Messier objects. Situated at a distance of about 35 million light
years it has a diameter of about 95,000 light years - roughly the same
as the Milky Way. There are an amazing 193 known HII regions in the
spiral arms.

http://www.martin-nicholson.info/ten...llenge/m74.htm

Martin Nicholson, Daventry, England.
http://www.martin-nicholson.info/1/1a.htm

Visit the Astronomical Hall of Shame at http://www.geocities.com/queen5658/

The Messier Ten Minute Challenge

Just out of curiosity why is it a 10 minute challenge when the image is made
from 7 x 90 second exposures?

In article , gs wrote:

The Messier Ten Minute Challenge

Just out of curiosity why is it a 10 minute challenge when the image is made
from 7 x 90 second exposures?

Because 7 x 90 seconds is ten minutes to the nearest minute?

-- Richard
--
:wq

Because 7 x 90 seconds is ten minutes to the nearest minute?

Well 630s could have gone either way as it falls on the half minute
depending on if you round up the half minute, or round it down. Normally
when rounding figures .5 or higher would be rounded up, half a minute would
therefore round upwards down.

On 27 Feb, 16:30, "gs" wrote:
The Messier Ten Minute Challenge

Just out of curiosity why is it a 10 minute challenge when the image is made
from 7 x 90 second exposures?

When the challenge was first made it was 10mins +/- 10%.

7x90s seemed better than 6x90, was better in fact. It was all just a
bit of fun and I don't know if the other people who took part still
lurk on this group? HV for example?