One Universe at a Time

Kepler-88 (also known as KOI-142) is a sun-like star about 1200 light years away.  It is one of the stars monitored by the Kepler satellite, which looks for minor fluctuations in a star’s brightness.  When a star’s planet passes between us and the star, some of the starlight is blocked by the planet, making it slightly dimmer.  The change isn’t …

In the late 1600s Isaac Newton wanted to measure the distance of the brightest star in the night sky, Sirius.  To do this he used a idea known as the inverse square law for light.  Although we now have experimental evidence for the inverse square law, in Newton’s time it was still a hypothesis. Imagine flash of light from an …

Today is Summer Solstice, which marks the beginning of Summer for those in the southern hemisphere. On this day the sun follows its highest path in the sky. Starting tomorrow the Sun will trace a lower and lower daily path until it reaches the Winter Solstice in December.  Of course most people live in the northern hemisphere, and for them …

Back in October I wrote about observations of superluminous supernovae.  These supernovae are more than ten times brighter than type Ia supernovae.  So powerful that it was postulated that they could be caused by a pair-instability interaction, where the gamma rays produced by the explosion have so much energy that they produce pairs of electrons and positrons. But another paper …

The majority of exoplanets we’ve discovered has been in one of two ways.  The first is known as the transit method.  In this method a planet’s orbit is aligned so that it passes in front of its star on a regular basis.  As it does so, it blocks some of the light coming from the star, making it appear dimmer. …

Jupiter’s moon Europa is an interesting world.  It is a bit smaller than our moon, and its mass and density suggests it has a rocky mantle and iron core.  But most interesting is its surface, which is not only icy, but remarkably free of craters.  Given that Europa’s surface has much fewer craters than we would expect, it would seem …

Suppose you wanted to know the room dimensions of a new apartment you’ve just rented.  So you buy a new tape measure (your old one is still packed) and start measuring rooms.  When you move your furniture in, you find that things fit pretty well, but it there are some things that are just slightly…off.  That dresser you thought would …

About a week ago I talked about the various kinds of meteorites and how one kind, pallasites are a mixture of iron-nickel and a mineral known as olivine.  In another post I talked about how some pallasites from the asteroid Vesta indicate it likely had a strong magnetic field in its early days.  I noted that we can identify these …

One way in which stars are categorized is by spectral type.  In the late 1800s we started to be able to measure the spectra of stars, which gave us the ability to determine the color of stars.  By the early 1900s, astrophotography allowed us to measure the color at which a star was brightest, and this led to the formal …