Astronomy Weekly Newsletter

Astronomy newsletter

Top new questions this week:

How can we tell the difference between matter and antimatter by observation in space?

I just was wondering and searching on the internet with little luck in the topic. On Antimatter Wiki they tell the observable universe is built up by matter. I read antimatter can be detected in ...

observation antimatter  
asked by CsBalazsHungary 5 votes
answered by OnoSendai 9 votes

Where might a semi proficient amateur analyst participate in meaningful astronomical efforts

I am a retired engineer that has an ongoing interest in space efforts. In my youth I did work on the Apollo program but on propulsion and vehicle thermal control: not flight dynamics. I have ...

planets data-analysis  
asked by tckosvic 4 votes
answered by andy256 0 votes

Longest and shortest wavelength

What is the longest and what is the shortest wavelength of light? How fast would a light-emitting object have to recede in order to shift the frequency of light to increase the wavelength from the ...

light wavelength  
asked by Astrony 2 votes

Is radiation from neutron stars delayed by time dilation?

I understand a neutron star to be the densest stuff that can exist without becoming a black hole, the densest thing which directly gives off radiation we can detect. At the event horizon of a black ...

black-hole neutron-star time-dilation  
asked by LocalFluff 2 votes
answered by Rob Jeffries 3 votes

What happens to galaxies when they die?

Stars explode when they die and blast heavy elements into space. Do galaxies do the same thing?

asked by Michael Lee 2 votes
answered by Mitch Goshorn 4 votes

Milky Way stellar number density : is the stated equation in this paper incorrect?

The paper is : The equation is equation #23 in the paper. It's a model for the density of stars in the Milky Way's disk. It ...

milky-way stellar-dynamics  
asked by John O 1 vote

Globular cluster star density as a function of distance from the center

Context: I want to simulate globular clusters in a simple way, just to display the positions of stars. Assuming isotropy, what would be a reasonable model of the stellar number density as a function ...

asked by John O 1 vote
answered by Rob Jeffries 2 votes

Greatest hits from previous weeks:

How many sun-like stars are there in the universe?

After yesterday's announcement of the Kepler telescope finding a huge amount of newly observed exoplanets, i saw a headline claiming that as much as 22% of sun like stars in the universe have planets ...

sun exoplanet universe  
asked by Haaakon 10 votes
answered by Moriarty 9 votes

How many stars and galaxies can be seen by the naked eye?

How many of the luminous dots that we see naked are galaxies and not stars from our galaxy? I imagine that the majority of the luminous points that we see naked eye during the night, are actually ...

star galaxy nebula naked-eye  
asked by Mario Stefanutti 8 votes
answered by called2voyage 3 votes

Can you answer this?

Why aren't secondary mirrors offset to get rid of diffraction spikes due to the support vanes?

Some kind of ellipsoidal shape mirror could reflect to a secondary mirror which is not in the way of the infalling light. Two advantages are immediately obvious. The primary mirror would not be partly ...

telescope optics  
asked by LocalFluff 1 vote
Subscribe to more Stack Exchange newsletters

Unsubscribe from this newsletter or change your email preferences by visiting your subscriptions page on

Questions? Comments? Let us know on our feedback site. If you no longer want to receive mail from Stack Exchange, unsubscribe from all emails.

Stack Exchange, Inc. 110 William St, 28th Floor, NY NY 10038 <3