Venus and moon beautify the night / Nova Centauri flares to naked eye brilliance

The crescent moon and Venus brighten up the western sky after sunset tonight Dec. 5, 2013.

Good old moon. It’s back again for another appointment with the planet Venus. Watch them this evening at dusk starting 20-30 minutes after sunset when they’ll light up the southwestern sky like a celestial holiday display.

Nova Centauri isn’t far from the bright southern stars Beta and Alpha Centauri. Alpha is the closest star beyond the sun at 4.4 light years or 26.4 trillion miles away. The map shows the sky facing southeast for skywatchers in Sydney, Australia just before the start of dawn tomorrow. Stellarium

On Monday Dec. 2 John Seach of Chatsworth Island, New South Wales, Australia, discovered a brand new nova in the constellation Centaurus the Centaur using only a camera with a standard 50mm lens. He photographed the region previously on Nov. 26; when he returned and re-photographed the same piece of sky, he noticed a bright star that wasn’t there before.

At discovery, the nova had already surpassed the naked eye limit at magnitude 5.5. Today, less than a week later, it’s rocketed up to magnitude 3.7; even under suburban skies the nova’s now an easy naked eye object. That’s brighter than Nova Delphini, which was discovered on August 14 this year and widely viewed by skywatchers around the world. Nova Del peaked two days later at 4.4 and has since faded to around 11th magnitude.

Comparison of the nova and its surroundings in Centaurus before and after eruption. Credit and copyright: Ernesto Guido, Nick Howes and M. Nicolini

The only downside of the new discovery is that it’s only visible from equatorial and southern latitudes. Northern hemisphere skywatchers will have to sit this one out, watching from afar via the Web. But if you live in Australia, the nova stand high in the southeastern sky below the Southern Cross and near the two brilliant stars Beta and Alpha Centauri shortly before the start of dawn.

Likely still rising in brightness, Nova Centauri has already oogled its way into the Top 20 brightest novae ever recorded. I’d love to go down and see it, but my vacation time’s done for the year.

If you’d like to make a map of precisely where to look for the nova, please check out the AAVSO’s Variable Star Plotter. Click the link and type in Nova Cen 2013 and you’ll get a chart showing the star along with magnitudes of other stars you can use to estimate its brightness.

Novae occur in close binary systems where one star is a tiny but extremely compact white dwarf star. The dwarf pulls material into a disk around itself, some of which is funneled to the surface and ignites in a nova explosion. Credit: NASA

Just as there’s more than one variety of apple, there are different kinds of novae. All involve close binary stars with a compact white dwarf stealing gas from its companion. The gas ultimately funnels down to the surface of the dwarf where it’s compacted by gravity and heated to high temperature on the star’s surface until it ignites in an explosive fireball. This is what you see when you look at a nova – a gigantic bomb going off.

To be clear, a nova doesn’t involve the destruction of the star, only a “shock to the system”. A supernova is a different beast entirely, resulting in the complete annihilation of a white dwarf or supergiant star. If a white dwarf accumulates too much matter from a companion and crosses the Chandrasekhar Limit, it can sidestep the nova stage and go straight to supernova.

You lucky southern folks! Enjoy your new guest and let us northerners know how things are coming along.

 

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About astrobob

My name is Bob King and I work at the Duluth News Tribune in Duluth, Minn. as a photographer and photo editor. I'm also an amateur astronomer and have been keen on the sky since age 11. My modest credentials include membership in the American Association of Variable Star Observers (AAVSO) where I'm a regular contributor, International Meteorite Collectors Assn. and Arrowhead Astronomical Society. I also teach community education astronomy classes at our local planetarium.

17 thoughts on “Venus and moon beautify the night / Nova Centauri flares to naked eye brilliance

  1. Hey Bob,

    I’ve been keeping up with your site via your RSS feed for a good while now – I enjoyed the ISON coverage.

    Just wanted to say I normally don’t have a good view of the Western horizon but tonight I took a walk down to my bank and WOW! The Moon and Venus were quite magnificent from where I live, where we’re blessed with dark skies and many clear nights :)

    Paul.

    • Hi Paul,
      Tbilisi – now that’s a far place from Duluth. You get to see the show in advance. One more hour and we’ll see it too. Thanks very much for writing. Glad you liked the comet coverage.

  2. Wow Dec.2 and bam that bright.. Awesome!. So what subtype/speed is it considered to be heading for? Does the alert info or early analysis show any clues that it could end up a trickster becoming more than a classical nova?

    • Hi Kevin,
      I’ve read through the lengthy AAVSO notice on the new object and they don’t say one way or the other yet. Spectra indicate the usual strong H-a and H-b lines at this point.

  3. Christmas concert at the School. It is so cold. I almost have to make myself go outside. But going outside is not necessary to see the Moon and Venus. I just saw them through my upstairs window. A beautiful sight but I have seen them much closer before.

  4. ISON is scheduled now to rise before twilight begins. With Hubble turning to it soon, we should know shortly the current magnitude of it.

  5. In what way did John Seach use his camera and 50 mm lens to find the nova?
    Did he just point it up at the same piece of sky every night and compare views from different nights?
    Thanks

  6. The last report I heard about ISON is that it is currently about magnitude 8, and about one half a degree in size. The report said that it would be high enough to see by the 12th and then magnitude 10 or dimmer.

  7. 2013 X1 Panstaarrs has a long way to go till April of 2016, when I predict that it could brighten to magnitude 7 or 8. Of course this is subject to change.

  8. I beieve I observed the Nova Cena 2013 this morning. I live in the Dominican Republic at Lat 18.463°N Long. 69.906W. At around 0530AM I can see the 4 major stars in CRUZ in the same field of view using my old NIKON 10×70 6.5°FOV binoculars. Around 0620 I just barely picked out HADAR down near the horizon viewing south at about 160°T just above the ocean and then vertically above it was an out of place bright star which must be the NOVA. correct. By that time the predawn lighting was blocking out most of the other stars.

      • Thanks AstroBob, I will try for a picture tomorrow morning using an old 300mm russian lens I will borrow. I have a Questar 3.5 but cannot get it down to -59° on the fork mount and in Alt/Az it wont track for a time exposure. The 300mm should catch something using a shorter exposure time I hope. If I get a shot can I put it here on this site?

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