According to the New York Times article How Many Stars? Three Time as Many as We Thought, Report Says, by Kenneth Clang, we may have underestimated by three times the amount. Scientists believe that by under counting the dim dwarf stars in certain galaxies astronomers may have a false understanding on how galaxies form and grow over the eons.
The problem is that astronomers cannot actually count the dwarf stars, which have masses less than a third on the Sun, in the galaxies outside the Milky Way. So alternatively they counted the brighter sun-like stars and assumed that there were about 100 unseen dwarf for each of the larger sun-like stars, since that is how the Milky Way is.
Researchers do not think every galaxy is like the Milky way. Dr. van Dokkum and Dr. Conroy used a new technique to establish the number of dwarf stars in elliptical galaxies. Dwarf stars are cooler so the fingerprint of certain colors they emit and absorb is different from that of larger stars. So without actually seeing individual stars astronomers could calculate the number of dwarf stars required to produce the telltale color fingerprint they detected in the light coming from the whole galaxy. Their finding showed that in eight elliptical galaxies the ratio of dwarf stars to sun-like was 1,000 or 2,000 to 1 opposed to 100 to 1 in the Milky Way.
"We may have to abandon this notion of using the Milky Way as a template for the rest of the universe," Dr. van Dokkum said. If the findings are correct, an undercount of dwarfs would mean astronomers have underestimated the masses of galaxies, and that would mean that galaxies developed earlier and faster than currently thought.
Although these findings seem astonishing, many are skeptical. For one, the research assumes that the stars in an elliptical galaxy are made of exactly the same stuff as those in spiral galaxies, which is an assumption that cannot be tested yet.
So for now, I think further information is needed to believe these findings.
This is a very interesting topic. I really do wonder how many stars there are in space. Hopefully the astronomers will be able to obtain the ability to count all of the stars in space. It is crazy how it is believed to be three times more the amount of stars than we originally believed there was.
ReplyDeleteI found this article to be very interesting; I always wondered how many stars were up in space. I think it would be really neat if astronomers are able to count all of the stars in space. I wonder how long that will take. It’s hard to believe there are so many more stars in space then we had originally thought.
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