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Full-Text Articles in Education
Tallgrass Prairie Center Newsletter, Fall 2018, University Of Northern Iowa. Tallgrass Prairie Center.
Tallgrass Prairie Center Newsletter, Fall 2018, University Of Northern Iowa. Tallgrass Prairie Center.
Tallgrass Prairie Center Newsletter
Inside This Issue:
--Irvine Prairie
--2018 Prairie on Farms Field Day
--IRVM Seed Pick Up
--Dr. Doug Tallamy
--New Staff at the TPC
--Save the Date
Biology News, Spring 2018, University Of Northern Iowa. Department Of Biology.
Biology News, Spring 2018, University Of Northern Iowa. Department Of Biology.
Biology News
Inside this issue:
-- Greetings from Biology
-- Biology Alumni
-- Department News
-- You Can Make a Difference
-- Support for Students
Perturbations Observed In The Orbital Elements Of The Spectroscopic Binary 57 Cygni, Kenneth W. Mclaughlin, Janak Panthi
Perturbations Observed In The Orbital Elements Of The Spectroscopic Binary 57 Cygni, Kenneth W. Mclaughlin, Janak Panthi
Journal of the Iowa Academy of Science: JIAS
We present spectroscopy that confirms periodic Doppler-shifts along with photometry that reinforces a lack of eclipsing in the double-lined spectroscopic binary 57 Cygni. Our spectroscopy concentrates on a range encompassing H-alpha and the helium 667.8 nm line, where we find Doppler-shifts of both stars resolved in the helium line but less so in the broader H-alpha profile. Although we find the radial velocities derived from both lines reasonably consistent, we retained only the helium-line derived velocities for sinusoidal curve-fits to the orbital dependence. The fit-amplitudes specify the ratio of the stellar masses as 1.03 ± 0.05, in agreement with previous …