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Feb
24
comment Was the Milky Way ever a quasar?
I didn't say the question wasn't a good one; merely that concept of quasar and an active AGN had been confused. Of course there are remnants of Sgr A*'s active phase (the Fermi bubbles are thought to be an example). If you had read the link I posted, you would have found that the "10,000 year claim" was the result of radio evidence of a SNR. According to the page, a supernova may have exploded near Sgr A*, starving it of matter to accrete. It is not my claim at all (see the paragraph below the picture pointing to Saggitarius A*); read more carefully.
Feb
24
awarded  Critic
Feb
23
comment Absolute magnitudes of stars
You might also check out the Extended Hipparcos catalog (XHIP). The main.dat file contains luminosities, spectral types, and temperatures, and the photo.dat file contains absolute magnitudes in Johnson bands. References are at the top of the linked page.
Feb
23
awarded  Supporter
Feb
23
answered If Venus and Mars changed places, would we then have 3 habitable planets?
Feb
23
answered How close would quasars have been to each other?
Feb
23
comment How can I calculate the orbital periods in a binary star system?
Use Kepler's third law! In particular, use Newton's form of Kepler's third law. See this page for the formula and an example.
Feb
23
answered Heavy bombardment - Why has things cooled?
Feb
23
comment Age of the universe
J2000 has nothing to do with keeping time. It is simply how we assign coordinates to stars (see this wiki page on astronomy en.wikipedia.org/wiki/Epoch_(astronomy). Astronomers use epochs to correct for things like stellar proper motions and the precession of the earth, which change the RA and Dec of stars over time. Chaonomy is either a crank or very poorly informed.
Feb
14
revised Can redshift be measured using fourier?
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Feb
14
comment Was the Milky Way ever a quasar?
Yeah, for some reason I remember reading something in your answer that I didn't like, but looking at it again it seems mostly okay. There are a few details that are still inaccurate: black holes do not form by accretion, although they do grow into SMBH's that way; if the jet points towards earth, it is a blazar (BL Lac or FSRQ), not a quasar; your answer somewhat confuses a quasar state with an active state.
Feb
14
revised Was the Milky Way ever a quasar?
deleted 30 characters in body
Feb
14
awarded  Revival
Feb
14
awarded  Teacher
Feb
14
answered Is it possible to calculate the time of day given latitude, longitude and solar elevation angles (zenith, azimuth, elevation)?
Feb
14
comment What are the masses of the two stars (given the information provided)?
Yes, but be careful of the units!! Note that equation has the masses in solar masses, the time in years, and the radius in AU.
Feb
14
answered Was the Milky Way ever a quasar?
Feb
14
awarded  Editor
Feb
14
answered What are the masses of the two stars (given the information provided)?
Feb
14
revised Can redshift be measured using fourier?
added 16 characters in body