Editing Drake equation (section)

====Rate of star creation in this Galaxy, {{math|''R''<sub>∗</sub>}}====
Calculations in 2010, from [[NASA]] and the [[European Space Agency]] indicate that the rate of star formation in this Galaxy is about {{solar mass|0.68–1.45|link=yes}} of material per year.<ref name=Robitaille>{{cite journal |author1=Robitaille, Thomas P. |author2=Barbara A. Whitney |title=The present-day star formation rate of the Milky Way determined from Spitzer-detected young stellar objects |journal=The Astrophysical Journal Letters |volume=710 |issue=1 |year=2010 |pages=L11 |arxiv=1001.3672 |bibcode=2010ApJ...710L..11R |doi=10.1088/2041-8205/710/1/L11|s2cid=118703635 }}</ref><ref name="The Drake Equation">
{{cite book
 |last=Wanjek |first=C.
 |year=2015
 |title=The Drake Equation
 |url=https://books.google.com/books?id=jcnSCQAAQBAJ&q=Robitaille+and+Whitney+came+up+with+a+figure+for+R*+between+0.68+and+1.45&pg=PA45
 |publisher=[[Cambridge University Press]]
 |access-date=2016-09-09
|isbn=9781107073654
 }}</ref> To get the number of stars per year, we divide this by the [[initial mass function]] (IMF) for stars, where the average new star's mass is about {{solar mass|0.5}}.<ref>{{cite journal |last1=Kennicutt |first1=Robert C. |last2=Evans |first2=Neal J. |title=Star Formation in the Milky Way and Nearby Galaxies |journal=Annual Review of Astronomy and Astrophysics |date=22 September 2012 |volume=50 |issue=1 |pages=531–608 |arxiv=1204.3552 |bibcode=2012ARA&A..50..531K |doi=10.1146/annurev-astro-081811-125610|s2cid=118667387 }}</ref> This gives a star formation rate of about 1.5–3 stars per year.

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