TAG: Stars
August 2, 2010– 3

As you go about your day, especially during the hot summer season, you probably don’t think much about the Sun other than that it makes you want to go for a quick dip in the swimming pool to cool off. After all, the Sun rises and sets every day (for those of us outside the Arctic and Antarctic Circles), and people just take it for granted without much thought.

The Sun is far more dynamic than you might think, although thankfully we don’t usually feel direct effects of its activity from Earth’s surface. The atmosphere and magnetic field of the Earth provide a nice buffer zone that protects us.

Every 11 years, the Sun completes a cycle that is fairly regular. During solar maximum, the number of sunspots is higher than usual, and during solar minimum (which we are just coming out of), it is relatively spot free.

The Sun is still coming out of solar minimum, but activity is slowly returning. At about 8:55 UTC on August 1, a measurable solar flare triggered an event known as a coronal mass ejection (CME). This is where the “atmosphere” of the Sun sends out a burst of energized plasma. In this case, nearly the entire Earth-facing side of the Sun was involved, so effects on the Earth are more likely. Here’s the X-ray signature of the solar flare that triggered the CME:

The X-ray signature of the solar flare that triggered the CME
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May 20, 2010– 4

Sitting in your office watching and cursing the rainy outdoors, have you ever wondered what the weather beyond our protective atmosphere is like?

Yes, there is weather even in the empty space above Earth’s atmosphere. Space weather typically refers to phenomena resulting from solar activity. It’s also one of the latest content additions to Wolfram|Alpha. Space weather includes things like sunspots, solar X-rays, and solar wind, as well as their effects on the Earth itself (e.g. aurorae, radio communication blackouts, and in extreme cases power outages).

The Sun has an 11-year cycle. Every 11 years, the number of sunspots rises to a peak and then falls to a minimum. Sunspots result from areas of strong magnetic fields on the Sun that cool the surrounding gas and makes the gas appear darker. When these tangled magnetic fields reconnect, the plasma carried along with it can be flung with huge amounts of energy away from the Sun. If it is directed toward Earth, we may observe a number of effects. Depending on how the magnetic field is oriented, it may bounce off the Earth’s magnetic field with no effect. If oriented the other way, the plasma funnels down the Earth’s magnetic field lines until it encounters the atmosphere, causing it to glow. This glowing is known as the aurora borealis in the northern hemisphere and the aurora australis in the southern hemisphere.

The sunspot cycle likely plays a role in Earth’s global climate. The exact nature of its effect is still a hot area of active research. More sunspots mean more energy is likely to be absorbed by the Earth from the Sun. Fewer sunspots mean less energy and potentially a cooler climate. Between 1645 and 1715, sunspots on the Sun nearly vanished. During the same period, called the Maunder minimum, Europe experienced colder-than-average temperatures, contributing to what some have called “the little ice age”. Data for sunspots goes back much further than most other space weather data. Most other phenomena could not be measured until the advent of artificial satellites, and many much more recently than that.

In 1859, the first and most powerful solar flare ever observed occurred, known as the Carrington event. Within a couple of days of the flare, the Earth’s magnetic field oscillated wildly from the magnetized plasma thrown toward us. The magnetic field lines of the Earth bounced back and forth across telegraph wires, causing massive failures and even melted wires from the induced currents. An event of that strength today would cause untold havoc, as we are far more dependent on telecommunications via both satellites and land-based wires. More »

August 28, 2009– 4

The amount of activity that takes place here on planet Earth is at times unfathomable. But it’s the merest drop in the bucket in comparison to the boundless amounts of activity in our universe—Earth is merely one planet within the Milky Way Galaxy. Most deep-sky objects cannot be seen by the naked eye, but observers looking through a telescope are treated to views of colorful clusters of light and fuzzy clouds of gas in the sky. Here we’ll demonstrate ways Wolfram|Alpha can help you find deep-sky objects such as galaxies, nebulae, and star clusters—our universe has about 100 billion member galaxies, and with so many, it’s nice to have a place to start.

Querying “galaxies” in Wolfram|Alpha will produce a list of some of the brightest as seen from Earth. Let’s compare the properties of the galaxies NGC 7544 and the nearby M 83 (well, only 15.78 million light years away). Wolfram|Alpha provides information including their approximate distance from Earth, Hubble type, apparent magnitude, equatorial position, and position in the sky and visibility from your current location. Keep in mind that object distances may not be available for all objects; one of the great mysteries of astronomy is that distance is notoriously difficult to determine except in special cases. More »

August 13, 2009– 8

Whether you are an astronomy student or just interested in learning more about those points of light in our sky, Wolfram|Alpha contains star data that will help you get started and understand what you’re seeing up there. Wolfram|Alpha not only charts the stars from your location, but offers detailed information including their distance from Earth, color, size, and much more.

To figure out which stars are the most visible to you, simply enter “10 brightest stars“. The query’s results indicate that the brightest stars as seen from Earth are the Sun, Sirius, Canopus, Arcturus, Rigel Kentaurus A, Vega, Capella, Rigel, Procyon, and Betelgeuse. Pods show comparisons of the stars’ size, their equilateral locations, and their locations in the current sky (not necessarily the night sky—unless you specify a time/location, Wolfram|Alpha assumes the current time from your current location).

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May 30, 2009– 8

Wolfram|Alpha continues to be a hot topic in online newspapers and magazines, blogs, Facebook, and beyond. But one of our favorite (and one of the most insightful) places to find chatter about Wolfram|Alpha is on Twitter.

People tweet Wolfram|Alpha results that amaze them. Some suggest features or domains we should add. Others ask questions about how to get the results they want. And what’s really great is to see people tweeting advice and recommendations to other users.

Here are a few of the tweeted results or suggestions that have caught our eyes or amused us:

  • @yooklyde: According to Wolfram|Alpha I was born approx. an hour before sunset, during a Full Moon. That last bit explains everything.
  • @petervogel: Students in my ICT classes continue to be fascinated with Wolfram Alpha; a given-name analysis seems to hook them.
  • @sqjtaipei: cool about the running calories expended… how about other sports… need swimming and cycling. thx.

We really enjoy reading and exploring your updates and responding when we can.

We also like Twittering to show you some of the many uses of Wolfram|Alpha.

We’re highlighting a different feature or input every day. Today, it was seeing stars with Wolfram|Alpha. Others have been such things as how to get tide forecasts, compute fuel usage, and figure out that tough crossword puzzle. Educational, practical, topical, just plain interesting—we’ll share it all. You’ve just got to follow us to find out.

We hope you enjoy the results we showcase. We’ll be watching for your ideas and favorite inputs—so be sure to include #wolframalpha in your next tweet.