A supernova named SN 1997 CW exploded in the galaxy NGC 105 in the constellation Cetus the Whale.?

It reached an apparent magnitude of +16.5 at maximum

brilliance, and its spectrum showed no hydrogen lines. Use this information to find the distance

to NGC 105.A supernova named SN 1997 CW exploded in the galaxy NGC 105 in the constellation Cetus the Whale.?I don't have an answer, as I'm too tired to work it out at the moment and I just want to go to sleep. However, I do want to comment that although the two previous answers look good, in terms of how they have approached the question, there seems to be something wrong with the answer 166 parsecs. The problem with this answer is that works out to be about 540 light years and that just can't be right because NGC 105 is a galaxy and if it were only 540 light years away it would be inside our galaxy! I'm wondering if that should be 166 kpc (kiloparsecs) or 166 Mpc (megaparsecs). As I mentioned, it's late, I'm tired, and I want to go to sleep, but I felt I had to contribute to this question. Also, NGC 105 appears to be in Pisces, not Cetus, although that is not terribly important in terms of working out the answer.



Good Luck!



P.S. Below is a link that you may want to investigate.



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Now that I've had a good long sleep, I see that the Astronomer from Mu Bootis (below) has contributed to this question and I am in agreement with his/her answer.



10^8.22 = 166 million



and this of course is measured in parsecs.



By the way, I've added a second link below that you may find interesting.



We certainly had a good team effort on this question, eh?



:-)A supernova named SN 1997 CW exploded in the galaxy NGC 105 in the constellation Cetus the Whale.?It was a 1a type of supernova

The absolute magnitude of a 1a type supernova at peak is -19.6(a number worth remembering..)

m(apparent) - m(absolute) = -5 + 5*log(distance) [log to the base 10]

16.5 - (-19.6) = -5 + 5*log(d)

36.1 =-5 + 5*log(d)

41.1/5 =log(d)

8.22 =log(d)

d =166 parsec approx.A supernova named SN 1997 CW exploded in the galaxy NGC 105 in the constellation Cetus the Whale.?Since it has no hydrogen lines it must be a Type 1a SN, therefore its absolute magnitude is -19.3.

Use the distance modulus:



16.5 - (-19.3) = 5logd - 5

and solve.A supernova named SN 1997 CW exploded in the galaxy NGC 105 in the constellation Cetus the Whale.?
540 million light-years or 166 million parsecs...just to stop beating around the bush...,