Camelopardalis the Giraffe

Camelopardalis the Giraffe
We don't hear much about the constellation of the giraffe, and you may even be wondering if this is a spoof story. But yes, it does exist – Camelopardalis [kah.MEL.o.PAR.da.liss] is a northern polar constellation whose official abbreviation is Cam. However even its brightest stars are so dim that the ancient Greeks had completely ignored them. Not a single one of them has a traditional name.

History
The constellation has no folklore attached to it. It was invented about 400 years ago by a Flemish astronomer and cartographer named Petrus Plancius (1552-1622). He presented Camelopardalis on a celestial globe in 1612, forming it out of neglected dim stars.

Camelopardalis looks like a strange name, but it's Greek for giraffe. Since a giraffe has a long neck that's somewhat camel-like and spots like a leopard, I suppose it was descriptive. The giraffe's scientific name is Giraffa camelopardalis. I'm less puzzled by the name than by why Plancius chose a giraffe for his creation, but no one knows. However Johannes Hevelius (1611-1687) took a liking to it and made Camelopardalis the centerpiece of one plate of his atlas. Oddly, it doesn't seem to have any spots.

Stars and planets
The three brightest stars are of the fourth magnitude. (The higher the magnitude number, the dimmer the star, with sixth magnitude stars being at the limit of our unaided vision). Interestingly, these three apparently dim stars are actually very luminous – they're all supergiants. However they're also very far away and further dimmed by the dust between them and us.

The brightest star in Camelopardalis is Beta Cam, a triple star system about 1000 light years away. The primary star is a yellow supergiant over 3000 times brighter than the Sun, and it has a binary companion that's around 25,000 AU away. (An AU is the astronomical unit – it's equal to the Earth-Sun distance.) It takes a million years or so to orbit the supergiant.

The second brightest star CS Cam is a binary star made up of a variable blue-white supergiant and its ninth-magnitude companion.

The third brightest star is the most interesting. Alpha Cam is a blue-white supergiant six thousand light years away. Although it looks dim from Earth, it's over half a million times brighter than the Sun. It's also a runaway star, zipping along at somewhere between 680 and 4200 kilometers per second. That sort of speed would get you from here to Jupiter in about five days. It's certainly fast enough for Alpha Cam's stellar wind to be at supersonic velocity as it collides with the gas and dust in the space between the stars. This produces a bow shock that's clearly visible in this infrared image from NASA's WISE spacecraft. Our Sun has a bow shock, but it's nearly invisible at any wavelength.

There are four stars which, as of February 2016, were known to have planets. Although HD 33564 b is in the habitable zone of its star, it – as well as the other three planets – is a gas giant much bigger than Jupiter. However if it has rocky moons, they might harbor life.

Deep Sky Objects
Kemble's cascade is an asterism, a recognizable pattern of stars that isn't a constellation. Amateur astronomer Father Lucian Kemble (1922-1999) described this colorful chain of stars as “a beautiful cascade of faint stars tumbling from the northwest down to the open cluster NGC 1502.” NGC 1502 is a small cluster with less than fifty stars about 3000 light years away.

NGC 1501 is a planetary nebula discovered by William Herschel (1738-1822). The central star is prominent in the Hubble Space Telescope image of the bubbly nebula. This is the star that has used up its hydrogen fuel, and is shedding the outer layers that form the nebula. It's nicknamed the Oyster Nebula since it looks like a bright pearl in a shell.

Another of Herschel's discoveries is NGC 2403, a spiral galaxy about 8 million light years away. NGC 2403 was the first galaxy outside our Milky Way's Local Group of galaxies found to have a Cepheid variable. These variable stars have been one of the keys to determining cosmic distances.

An unusual dwarf irregular galaxy NGC 1569 lies about eleven million light years distant. It contains two massive star clusters. In one of them the star formation took place long ago, and most of the stars are old. In the other a burst of starbirth began around 25 million years ago, and continues to supply the cluster with young stars.

The most distant galaxy ever discovered could be MACS0647-JD. Remember that a telescope is a time machine, and as we look at ever more distant objects, we're looking further back in time. In this case the Hubble Space Telescope was looking back to a time when the Universe was three percent of its present age. However it was only able to do this by using the massive galaxy cluster MACS J0647.7+7015 as a gravitational lens to increase the brightness of the distant galaxy.

Four supernovae have been discovered in Camelopardalis. Perhaps the best known one is known because its discoverer was a 10-year-old Canadian girl. She was examining star pictures in search of supernovae. Although unlikely that she'd spot one, in fact she did discover SN 2010lt. It was 240 million light years away in galaxy UGC 3378. At the time, she was the youngest person ever to discover a supernova, but since then her younger brother has claimed the record.



You Should Also Read:
ABC of Astronomy – G Is for Gravitational Lens
Young Astronomers Reveal the Universe
Johannes Hevelius

RSS
Related Articles
Editor's Picks Articles
Top Ten Articles
Previous Features
Site Map





Content copyright © 2018 by Mona Evans. All rights reserved.
This content was written by Mona Evans. If you wish to use this content in any manner, you need written permission. Contact Mona Evans for details.