A pictorial essay on the wonders of one of the brightest stars in the Earth's sky - Vega. For maximum enjoyment, go use full-screen!

1. A Stellar Journey
VEGA
A pictorial essay by Faizan Majid, Karachi, Pakistan
Picture credit: Vega by Martin Mitchell of Nottingham, England. All rights reserved, used with the owner’s permission.

2. Where is it?
On a typical summer night in the
Northern Hemisphere, the most
prominent feature of the sky is a trio
of bright stars, almost overhead,
known as ‘The Summer Triangle’.
Vega is the brightest of the three stars
– glowing a bright bluish-white.
Picture generated with Stellarium
Let’s take a closer look…

3. Why is it so bright?
You might notice its incredible brightness – indeed it is the fifth brightest star in the Earth’s sky!
The main reason is its nearness rather
than its actual size or brightness…
At 26 light years, it is one of the Sun’s
nearest stellar neighbours!
(1 light year = 10,000,000,000 km
approx.)
Picture: Vega through Celestron CGEM DX 1100 telescope
Picture courtesy Drew Farrell, licensed under Creative Commons Attribution-Share Alike 3.0 Unported
However, let’s not underestimate its
power…
Vega is twice as massive as the Sun,
and about 40 times as bright!
The reason its nearness is more
important than its size in making it seem
bright is that there are lots of other
larger, brighter stars.
That should give you some idea of how
tiny and dim our Sun is in the great
scheme of things.
And that’s not all…

4. It’s coming closer!
The speed of a star towards or away from us can be
measured using the Doppler effect on its light
spectrum.
Just like an approaching car’s horn sounds like it has a
higher pitch, light from approaching stars is shifted to
higher frequency (i.e. ‘blue-shifted’).
Using this method, we know Vega is approaching the
Sun at 14 kilometres per second!
This also means Vega is becoming brighter…about
200,000 years in the future, it will be the brightest star in
the Earth’s sky!
Picture: Vega. Courtesy: Roberto Mura; Public Domain.
But Vega has also played an important role in Man’s past…

5. It Showed the Way
Vega used to be the Earth’s ‘North Star’
14,000 years ago – the title now goes to the
star ‘Polaris’.
This title is given to the star directly above
the Earth’s North Pole. Such a star is
invaluable in finding directions at night,
especially when no modern means like GPS
are available.
The North Star changes with time because
the Earth’s rotation is wobbly, like a spinning
top coming to a stop (‘precession’).
This cycle repeats every 26,000 years so, in
12,000 years, Vega will again be North Star
Picture: Polaris Timelapse. Courtesy Eneas De Troya from Mexico City, Mexico
licensed under Creative Commons Attribution 2.0 Generic
But a guide post is not all has been for Man…

6. A star in more ways than one!
Vega has ‘starred’ in a movie – the 1997 blockbuster
‘Contact’!
Based on Carl Sagan’s novel of the same name, the
movie showed Vega as the source of alien radio
communications that change the world forever.
But Vega has had a strong impact on human
culture, mythology and astrology in many ancient
civilizations – Arab, Egyptian, Indian, Roman,
European, and Chinese, among others.
Even the modern name ‘Vega’ is derived from its
ancient Arabic title ‘Al-Nasr-al-Waqi’ meaning ‘the
falling eagle’.
Picture: Long exposure shot of the European Southern Observatory’s APEX radio telescope in Chile
Courtesy ESO/S. Brunier, licensed under Creative Commons Attribution-Share Alike 3.0 Unported
So, what would an actual visit to Vega be
like?

7. It’ll make your head spin!
Vega is spinning rapidly - once very 12.5
hours.
For comparison, the Sun, which is about half
as massive, takes 27.5 days to rotate once.
In fact, if Vega was to rotate just 11% faster, it
would become unstable and fly apart!
Because of this rapid rotation, Vega is
considerably oval-shaped rather than
spherical, as shown in this image.
Another effect of this rapid rotation is that it is
dimmer along the middle, bulging part – an
effect known as ‘gravity darkening’, also
shown in this image. Since it bulges outward,
the middle part experiences less gravity, and
produces less energy.
Picture: Artist’s conception of the effects of Vega’s rotation
Courtesy: J. Aufdenberg and NOAO/AURA/NSF. All rights reserved. Used under NOAO/AURA Image Library Conditions of Use (Educational/Research Use).
So, the big question
is…

8. Could there by life around Vega?
Vega is surrounded by not one, but two orbiting asteroid
belts – rocks and dust warmed by the star’s light so they’re
detectable in infrared.
The belts are clearly separated – the inner one much warmer
than the outer one.
This separation suggests that Vega may be orbited by
multiple planets, sweeping the space between the belts
clear.
NASA’s future James Webb Space Telescope, the successor
to the Hubble Space Telescope, may be able to image
these planets directly in the future.
Who knows what we may find there…
Picture: Artist’s concept of debris around Vega
Courtesy NASA/JPL Caltech. Public Domain Important Notice: This slideshow is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 U
THE END

9. References / Further Reading
General
• http://www.solstation.com/stars/vega.htm
• http://www.stellar-
database.com/Scripts/search_star.exe?Name=vega
Slide # 2
• http://earthsky.org/favorite-star-patterns/the-summer-triangle-
roadmap-to-the-milky-way
• http://apod.nasa.gov/apod/ap100625.html
Slide # 3
• http://www.solarsystemquick.com/universe/vega-star.htm
Slide # 4
• http://www.madsci.org/posts/archives/apr2000/956230963.As.r.ht
ml
Slide # 5
• http://www.space.com/15567-north-star-polaris.html
• http://www.badastronomy.com/bad/misc/badpole.html
• http://csep10.phys.utk.edu/astr161/lect/time/precession.html
• http://www.youtube.com/watch?v=8z97i3FBhSs
Slide # 6
IMPORTANT NOTE: The astrology-related links are shared because
they have interesting references to Vega’s historical and cultural
influence. The author does not believe in or condone astrology. It is
not a science, there is no evidence that it works, and it is not related
in any meaningful way to the science of astronomy.
• http://earthsky.org/brightest-stars/vega-brilliant-blue-white-is-
third-brightest-star
• http://www.skyscript.co.uk/lyre.html#wega
• http://www.constellationsofwords.com/stars/Vega.html
Slide # 7
• http://www.noao.edu/outreach/press/pr06/pr0603.html
• http://www.space.com/1930-rapid-rotation-distorts-bright-star-
vega.html
Slide # 8
• http://asd.gsfc.nasa.gov/Marc.Kuchner/vegaanim.html
• http://www.jpl.nasa.gov/news/news.php?release=2013-012
• http://scitechdaily.com/vega-older-than-previously-thought-
could-harbor-life/
Notes:
If the hyperlinks do not work on clicking, please copy and paste into your browser’s address bar.
No responsibility is taken for the links’ contents. However, these are reputable sites and their information may be expected to be reasonably accurate.
This is not an exhaustive list, merely a starting point. Google away for lots more regarding Vega!