A new star explosion, called a nova, has flared up in the night sky,
and it is fairly easy to spot with binoculars — and potentially even the
naked eye — by stargazers with clear weather and dark skies. You can
even see the new nova online tonight in a skywatching webcast.
Called Nova Dephinus 2013, the new nova (Latin for "new star") was
discovered Wednesday (Aug. 14) by amateur astronomer Koichi Itagaki of
Yamagata, Japan, at 2 p.m. EDT (1800 GMT) in the constellation
Delphinus, the Dolphin. Itagaki used a CCD camera attached to a 7-inch
reflecting telescope.
A nova is a powerful eruption from star, but is not as strong as a
supernova, which is a catastrophic explosion that signals the death of a
star.
Weather permitting, you can
see the star explosion in a webcast on SPACE.com tonight,
courtesy of the online Slooh Space Camera. The webcast will begin at 7
p.m. EDT (2300 GMT) and feature views of Nova Delphinus 2013 from the
Canary Islands off the western Africa coast. [
See photos and sky maps of the new nova star explosion]
"Slooh members have already imaged the nova, and it looks amazing," Slooh President Patrick Paolucci told SPACE.com.
The new nova's visual magnitude was estimated at +6.8, meaning it was
just below the threshold of visibility with the naked eye on the
magnitude scale used by astronomers to measure brightness of
night skyobjects. (The lower the number, the brighter the object.)
The new nova was not present in a photo taken by Itagaki on Tuesday
(Aug. 13), when he observed stars down to a magnitude +13, so overnight
it had brightened at least 300-fold. More likely, however, it initially
was much dimmer — perhaps as faint as magnitude +17, implying that in
less than 24 hours it may have increased in brightness by more than
10,000 times!
I was able to view the nova from my home in Putnam County, N.Y. just before midnight on Wednesday night with 7x35
binocularsand
estimated its brightness at magnitude +6. So since its discovery some
10 hours earlier, the nova had doubled in apparent brightness, and it
might continue to get even brighter over the next day or two.
The location of the star explosion Nova Delphini
2013 is seen in the Delphinus constellation (the Dolphin). This photo is
by astrophysicist Gianluca Masi of the Virtual Telescope project. The
nova was discovered by Japanese astronomer Koichi Itagaki of Yamagata,
Japan. Image released August 14, 2013.
Credit: G. Masi, P. Schmeer and F. Nocentini/The Virtual Telescope Project 2.0
How to see the new nova
Nova Delphinus 2013 is located within the boundaries of the small
constellation of Delphinus, the Dolphin, which is immediately adjacent
to the famous Summer Triangle composed of the bright stars Vega, Altair
and Deneb. Delphinus is recognized for a small diamond of four
moderately dim stars that are sometimes referred to as "Job's Coffin."
Astrophysicist Gianluca Masi, who oversees the online Virtual Telescope
Project for stargazing, snapped images of the new nova and plotted its
position in sky maps.
"This nova is now close in brightness to the faintest stars visible
with the naked eye from a dark place. It is a very easy object with a
small pair of binoculars or a
little telescope,"
Masi wrote on the Virtual Telescope Project website.
The nova is situated roughly 5 degrees above the diamond (your clenched
fist held at arm's length measures roughly 10 degrees). Near Delphinus
is the similarly small and dim constellation of Sagitta, the Arrow. By
coincidence, the arrowhead of this star pattern seems to be pointing
almost directly at the nova.
As darkness falls around 9:30 p.m. local time, Delphinus can be found
high in the southeast sky. It reaches its highest point about two-thirds
up from the southern horizon to the overhead point (called the zenith)
at midnight and is still visible about one-third up from the western
horizon as dawn is breaking (at around 5 a.m. local time). So currently
you can actively search for the nova at any time during the course of
the night, as it will always be above the horizon.
http://www.space.com/19422-bursting-star-pairs-between-nova-and-supernova-video.html
Nova vs. supernova
You may have have heard of the terms "nova" and "supernova," but they refer to two completely different phenomena of
star evolution.
What we see as a nova is believed to originate from the surface of a
white dwarf star in a binary system. If these two stars are close
enough, material from one star can be pulled off the companion star's
surface and onto the white dwarf, producing an extremely bright outburst
of light.
When the outburst has subsided, the white dwarf usually reverts back to
its original state. This likely is the case for the nova discovered in
Delphinus. Interestingly, we have observed stars that have gone through
such contortions more than once.
But there is no second time for a
supernova.
In a supernova scenario, a star, far more massive than our sun and
nearing the end of its life, suddenly blows itself apart and in the
process briefly shines with an apparent brilliance of more than 100
billion normal stars! [
Spectacular Supernova Photos of Star Deaths (Gallery)]
How common are novas?
Bright naked-eye novas appear perhaps once or twice per decade.
During the last 50 years, the brightest nova that has appeared occurred
in August 1975, when a nova suddenly blazed in the constellation of
Cygnus, the Swan. It reached magnitude +1.8 — brighter than Polaris, the
North Star, though not quite as bright as first-magnitude Deneb, the
brightest star in Cygnus.
The last naked-eye supernova to flare in our galaxy appeared in the
constellation Ophiuchus in the year 1604 and equaled or rivaled the
planet Jupiter in brightness. We are overdue for another.
Shades of '67
The announcement of a nova in Delphinus stirred up a childhood memory
for me. Back in the summer of 1967, when I was a budding young amateur
astronomer living in The Bronx, N.Y., a nova appeared in Delphinus, not
far from where our current nova now resides. After its discovery in July
1967, Nova Delphini vacillated between magnitude 4.5 and 5.5.
By mid-September, the star seemingly leveled off at around fifth
magnitude, but then suddenly in mid-December its brightness unexpectedly
spiked at magnitude 3.5, making it a rather easy naked-eye object
before it faded just as rapidly by year's end.
What will this latest version of a nova in Delphinus do? We really
don't know, but it certainly will be something worth monitoring in the
days and weeks to come.
You can watch the Slooh webcast of Nova Delphinus 2013 directly on the Slooh website at:
http://www.slooh.com
Editor's Note: If you snap an amazing picture of the
new nova star explosion, or any other night sky view that you'd like to
share for a possible story or image gallery, send photos, comments and
your name and location to managing editor Tariq Malik at
spacephotos@space.com.
Joe Rao serves as an instructor and guest lecturer at New York's
Hayden Planetarium. He writes about astronomy for Natural History
magazine, the Farmer's Almanac and other publications, and he is also an
on-camera meteorologist for News 12 Westchester, N.Y.