Looking Up: A Rising Constellation 'Kite' Signals Spring

Mar 19, 2018

If you're seeing Bootes rising in the east can spring be far behind?
Credit Till Credner, AlltheSky.com / Creative Commons / Wikimedia Commons

This week on Looking Up we learn about a rising star in the east that is a harbinger of spring and summer weather.

We are only a couple days away from the beginning of Spring, at least astronomically speaking. And for astronomers, one of the stars we look for as a sign that warmer days are ahead is the brilliant Arcturus, the brightest star in the roughly kite-shaped constellation of Bootes.

Back in 2015 we talked about the weird and wonderful Arcturus, so today let’s talk about the much less discussed but also very interesting star at the other end of the kite shape, the star whose name means “ox driver,” the lovely Nekkar.

Nekkar is about 220 ly away, and is roughly 20 times bigger than our Sun. It is also much brighter than the Sun, throwing off 190 times more light. A relative baby at only 350 M years old, Nekkar hasn’t been a good baby – it’s burned through most of its core elements and is about to expand into a red giant star.

Nekkar is also, well, weird. It rotates on its axis about once every nine months compared to our Sun’s 28-day cycle. And every now and then, it throws off very powerful bursts of X-rays. Once in 1993, Nekkar was observed to emit a massive blast of X-rays, but for only 10 minutes. It was thought to be too cool a star for such things, but Nekkar was a surprise. You might say astronomers weren’t sure, maybe they had a Nekkar wavier? 

Credit Egres73 / Creative Commons / Wikimedia Commons

If you’d like to take a closer look at Nekkar or any of the other wonderful and amazing things in the sky, please visit csastro.org for a link to information on our monthly meetings and our free public star parties.