More than 50 years ago, a Norwegian astronomer named Sjur Refsdal outlined an interesting new method for calculating the Hubble constant. Last November, astronomers found the perfect test case.
Stars formed in the early Universe were extremely massive and extremely low in elements heavier than helium. The transition from the first to the second generation of stars is still hidden in the shadows of the past. However, simulations of the most massive supernovae can help us to decipher the way of how the life cycle of stars came into being.
Cepheids are bright enough that we can use them to measure distances to other galaxies, but their luminosities also makes detecting their companions particularly difficult. So how do astronomers find their uncover their secret partners? Today’s paper takes a look…
How can we measure the temperature of the Universe across cosmic epochs? Recent data from Planck suggests that the Universe’s cooling history is consistent with the Big Bang model.
Distance is a tricky thing to measure in astronomy. We can’t use tape measures or rulers, and even more sophisticated methods like laser ranging are only good for the very nearest of neighbors, like the moon. That’s where distance indicators like Cepheids come in.
The El Gordo (in Spanish, “the fat one”), one of the most massive galaxy clusters observed, is an active merger of two large subclusters. Unraveling its dynamics provides insights into $latex \Lambda$CDM.