Skynotes for November 2012

jfSDAS

hi all,

Sorry I've been off-air recently. The notes for this month are below and feel free to drop me a note if any comments or corrections. Some items in the notes are adopted from those prepared by Neill McKeown of the Northern Ireland Amateur Astronomy Society.

John


Skylight for November 2012
Look closely at the second star in the handle of the Plough some evening. After a few moments you might spot a fainter sun very close to it. That's Alcor, a companion to the primary which is known as Mizar. With the invention of the telescope, Mizar itself was found to be a double star while later observations discovered that both these are what are termed spectroscopic binaries — when the stars are too close to be separated in a telescope but can be inferred from periodic Doppler shifts of the lines in their spectrum.

Within the same binocular field as Mizar is an unrelated eighth magnitude star that goes by the grand title of Sidus Ludoviciana. This star had a brief period of fame when it was misidentified as a new planet in the early 1700s.

Johann Georg Liebknecht, a German university professor, was observing Mizar on the evening of December 2nd, 1722 and chanced upon an eighth magnitude sun in the same field of view. Inaccurate positional measurements of the star led him to believe that he had detected it slowly moving against the background stars.

Convinced he had found a new planet, Liebknecht hastily named it Sidus Ludoviciana in honour of his monarch the Landgrave Ludwig of Hessen-Darmstadt. Other astronomers were not so convinced and reacted unfavourably to Liebknecht's pamphlet announcing his find. Some of them had looked with far superior telescopes and found that Liebknecht's "planet" was a fixed star that showed no motion.

Less kind criticism of Liebknecht came from other quarters stating that it was unnecessary for the German professor to announce every telescopic star as new and give it a special name. Liebknecht published a 16- page abusive retort but the exchange soon waned.

Sidus Ludoviciana is now just a curious footnote but is worth seeking some night as part of the rich astronomical lore of the heavens.

See also ...
· http://earthsky.org/brightest-stars/mizar-and-alcor-the-horse-and-rider
· http://www.leosondra.cz/en/mizar/ -- a detailed history along with a finder chart for Sidus Ludoviciana

The Sun
See http://www.sunrisesunset.com/predefined.asp to create a sunrise/sunset calendar for the month and http://www.suncalc.net for details of the current day's sunrise/sunset positions overlaid on a map.

Something different this month in that I'd like to highlight a branch of the hobby which probably falls somewhere between astronomy and weather. The subject is meteorological optics, the wonderful range of phenomena that are painted across the sky through the interaction of sunlight (or moonlight) and water in various forms (ice or raindrops): Two simple ingredients that produce delightful dishes such as halos, rainbows, sundogs, and much rarer treats.

The premier site on the subject is that run by Les Cowley at http://www.atoptics.co.uk/ where you will find photographs and descriptions of a riot of colour in the sky. Click through to the Resources section and you will find other links along with a list of books on the subject. For a general read though I highly recommend Kaleidoscope Sky by Tim Herd, whose site http://www.kaleidoscopesky.com is well worth browsing too.

A total solar eclipse on November 13/14 is visible along a track that crosses northern Australia, just north of New Zealand, and ends just off the Pacific coast of South America -- the dual date is because totality crosses the International Date Line. A group of amateur astronomers are travelling from Ireland to see the event.

The Moon
Last Quarter Moon is on November 7th, New Moon on the 13th, First Quarter on November 20th, and Full Moon on the 28th (when there will be a penumbral lunar eclipse, but the event is not visible from Ireland).

• On the evening of the 1st, the waning gibbous Moon lies 3° to the west of Jupiter at around 9pm.
• On the morning of the 11th, the waning crescent Moon lies 7° to the west of Venus at around 6pm.
• On the morning of the 12th, the waning crescent Moon lies to the west of Saturn at around 7am.
• On the evening of the 28th, the Full Moon lies 3° to the west of Jupiter at around 7pm.

The Planets
Mercury passes through inferior conjunction on the 17th and then becomes visible at the end of the month as a magnitude -0.3 object low in the southeast before dawn. The planet rises just before 6:30am on the 30th when a line drawn down towards the horizon through Saturn and Venus will point the way to Mercury.

Venus is a brilliant beacon in the morning skies this month and fades slightly from magnitude -4.0 to magnitude -3.9. The planet lies 4° to the northeast of Spica in Virgo on the morning of the 17th and closes to within 0.5° of Saturn on the morning of the 27th. Venus shows a gibbous phase in a small telescope at the moment .

Mars just about stays visible very low in the evening twilight during November. The crescent Moon nearby on the 16th will aid you finding the magnitude +1.2 world, but don’t expect to see any detail though as the Martian disk measures only a paltry 4 arc-seconds across at the moment. See http://www.jodrellbank.manchester.ac.uk/astronomy/nightsky/ for a screenshot from Stellarium.

Jupiter dominates our evening skies this month and is nestled amongst the stars of Taurus. The gas giant brightens slightly from magnitude -2.7 to -2.8 as it nears its December opposition date. The nightly dance of Jupiter’s four largest moons – Io, Europa, Ganymede, and Callisto – can be followed even with just a pair of binoculars. Recently, we were pleasantly surprised to spot Io reappearing from behind Jupiter’s disk as the moon came out of eclipse. The Galilean satellites undergo various phenomena that can be followed in a small telescope such as shadow transits, eclipses, and occultations. Predictions for these events can be found in any of the monthly astronomy magazines or by using Irish amateur astronomer Gary Nugent’s JupSat software, available from http://astrotips.com/software/jupsat-95 (freeware) or http://www.nightskyobserver.com/JupSatPro/ (latest version).

Saturn slowly moves out of the solar glare and will be visible in the second half of the month as a morning sky object in Virgo. The planet rises just after 5am by the 30th when it will be a magnitude +0.6 object. Telescope users will see the rings tipped Earthward by 18° and steadily held binoculars will let you spot its largest moon Titan. See above for details of Saturn’s close encounter with Venus.

Both Uranus and Neptune can be seen in the evening sky during November. Uranus (magnitude +5.8) can be found in Pisces and lies to the east of the constellation’s Circlet asterism. The planet remains on view until just after 2am. The window of opportunity to spy Neptune is shorter though as the planet sets just before 11pm by the end of the month. Look for Neptune as a magnitude +7.9 “star” in Aquarius. The charts provided at http://www.skyandtelescope.com/observing/objects/planets/12435011.html will aid your search.

Comets
C/2012 K5 (Linear) is brightening and expected to be magnitude +10 during November. The predicted peak is for around magnitude +8 at Christmas time. The comet is visible all night in November and at the beginning of November it will lie near the star gamma Boötis before crossing into Ursa Major by the end of the month. Details of this and other comets can be found on the BAA's Comet Section web site http://www.ast.cam.ac.uk/~jds/ as well as http://www.aerith.net/comet/future-n.html and http://cometchasing.skyhound.com/

168P/Hergenrother is fading from its peak magnitude of approximately +8 and is now +10. The comet surprised astronomers in October by surging six magnitudes in brightness in only a few days. This led them to believe a disruptive event had taken place in the nucleus. Intense study was followed by eventual confirmation of this theory as a team photographed a secondary object that seemed to have split from the main body of the comet. More details of the discovery can be found at http://remanzacco.blogspot.it/2012/10/splitting-event-in-comet.html

Meteors
The Northern Taurids peak on the night of the 12th with a hourly rate of 5. The waning crescent Moon sets during daylight hours on the 12th though which means viewing conditions will be excellent. The radiant is visible from 8pm. The Northern Taurids are associated with comet 2P/Encke and can produce a large number of fireballs -- the most recent occasion this happened 2008 and there are indications we may encounter a "swarm" of fireball-producing meteoroid material in 2012. A paper by Dr David Asher of Armagh Observatory at http://star.arm.ac.uk/~dja/taurid/swarmyears.html has more details, along with http://astroguyz.com/2012/10/22/astro-event-a-possible-taurid-swarm/

The Leonids peak on the morning of the 17th with a ZHR of 15. The waxing crescent Moon sets just before 7pm on the evening of the 16th which will also offer excellent viewing conditions for this annual display. The radiant doesn't rise until 2am though and can be found in the "Sickle" of Leo.

Details of annual meteor showers can be found at http://www.imo.net/calendar/2012 or http://meteorshowersonline.com/calendar.html

Asteroids
No bright asteroids are at opposition this month but a number can be swept up in binoculars or a small telescope. Check out http://www.calsky.com/ for a staggering collection of computational aids on just about everything that is visible in the sky. The Asteroids page on CalSky shows two opposition events brighter than magnitude +10 during November, while a number of other asteroids are also on view around this time.

Exploring further
The following web sites are also a great resource for information about what’s on view in our skies during the month -- we also recommend downloading the free planetarium program Stellarium at http://www.stellarium.org/

http://www.skymaps.com — superb charts you can download
http://www.jb.man.ac.uk/astronomy/nightsky/
http://www.guardian.co.uk/science/series/starwatch
http://www.telegraph.co.uk/news/newstopics/nightsky/
http://www.heavens-above.com — space station predictions
http://dcford.org.uk/index.php -- the Digital Astrolabe
http://earthsky.org/astronomy-essentials -- absolutely essential reading for what's up

http://www.jodcast.net — monthly night sky tour for MP3 players

http://www.spaceweather.com – details of transitory events during the month as well as aurora alerts

http://spaceflightnow.com — mission launches and other news (click “Launch Schedule” too)

http://www.skymania.com – astronomy and space news
http://www.universetoday.com – more astronomy and space news
http://www.nightskyobserver.com/the-sky-this-month.php -- Gary Nugent’s astronomy and space news

http://calgary.rasc.ca/downloads/ -- has two excellent documents on buying telescopes and binoculars

Zubeneschamali

jfSDAS wrote: »

No bright asteroids are visible in binoculars this month but a number can be seen in a small telescope.

I just spotted Vesta last night with 10x50s, despite the moonlight and streetlights, and indeed your Calsky link says it's at mag 7.2

jfSDAS

Zubeneschamali wrote: »

I just spotted Vesta last night with 10x50s, despite the moonlight and streetlights, and indeed your Calsky link says it's at mag 7.2

Well done on tracking down Vesta ... it's amazing to think a spacecraft was circling that world until very recently!

A possible chart to use could be the one linked to from http://rasnz.org.nz/Asteroids2012.shtml (their other pages on what's up in 2012 are excellent too) but I can see how cluttered the star field in Taurus is!

I've corrected the notes above to better say that no bright asteroids are at opposition in November. Many thanks for pointing out the error I made.

John

IamtheWalrus

What is the name of the very bright start to the east of the moon tonight?

jfSDAS

IamtheWalrus wrote: »

What is the name of the very bright start to the east of the moon tonight?

That's Jupiter and it will be well placed in the evening sky the next few months (the planet reaches opposition in December).

Look for the Pleiades (Seven Sisters) and Hyades star clusters nearby too -- although the Moon's glare will make spotting them a bit more difficult 'til it moves out of the way the next few nights. There's also two often overlooked nice NGC clusters in Taurus visible in binoculars that are worth hunting down.

Clear skies!

John

IamtheWalrus

jfSDAS wrote: »

That's Jupiter and it will be well placed in the evening sky the next few months (the planet reaches opposition in December).

Look for the Pleiades (Seven Sisters) and Hyades star clusters nearby too -- although the Moon's glare will make spotting them a bit more difficult 'til it moves out of the way the next few nights. There's also two often overlooked nice NGC clusters in Taurus visible in binoculars that are worth hunting down.

Clear skies!

John

Great! I suspected it was Jupiter and took some pics. I think that's the fist time I've seen another planet (well, been aware of it). How exciting.

Zubeneschamali

If you're up before the sun, Venus is really bright in the East, you can't miss it. Then you'll have seen 3 planets!

jfSDAS

Would be interested in seeing those photos if you have a link to them.

The web sites listed at the bottom of the sky notes post above will have details of other planet-spotting opportunities -- I'd especially recommend earthsky.org as they have nice graphics showing the alignments (albeit for latitudes of the US, but the Stellarium program will let you draw the view from Ireland).

Two guides worth procuring are;

"Stargazing 2013" which is currently in Easons, Reads, and Hodges Figgis, or via an online bookstore. It is a month-by-month guide to the night sky for the year ahead. It is published by Philips and costs €10.

The publication of "Nightscenes 2013" has been delayed and I suspect it's because Paul is probably adding information about comet ISON, which is predicted to be prominent in our skies towards the end of 2013. See http://www.astrospace.co.uk/Astrospace/shop/publications.html for details. It's often stocked by Hodges Figgis in Dublin but can be purchased direct from Paul or on Amazon.

Another annual staple is Guy Ottewell's "Astronomical Calendar" and you can see a preview at http://www.universalworkshop.com/AC.htm along with ordering info. I buy it either direct from Guy's site or on Amazon. It's a very large format publication but packed with tons of info.

atb,

john

IamtheWalrus

jfSDAS wrote: »

Would be interested in seeing those photos if you have a link to them.

To be honest the pics weren't great but I'll definitely post them up here. I'm using a Canon 650D with a 135mm lens. Do any of you know a camera like that can take decent sky pics?

jfSDAS

Lots of possibilities with that camera ... the key is practice, practice, practice, with a good dash of creativity added too. Another tip is to keep an eye on the web sites listed above for details of upcoming astronomical events like bright comets, meteor showers, planet conjunctions with the Moon, etc. These are the occasions when you'll get those great images too.

For example, have a look at The World At Night's web site where you'll see what people are achieving with standard kit to image the night sky in awesome landscapes. The site is http://www.twanight.org/newTWAN/index.asp

Another great site is that hosted by Jerry Lodriguss at http://www.astropix.com/ -- all his gallery images have full details of equipment used as well as the time & processing data. There's quite a few taken with the 550D/T2i, which is what I use. I was actually just talking to Jerry on e-mail during the week about one of his images of Hale-Bopp. His pages linked to at http://www.astropix.com/HTML/I_ASTROP/TOC_AP.HTM are required reading, as are many others on his web site.

The above should get you started but feel free to pose any other questions for myself or other forum members to answer.

Have a good weekend!

john

IamtheWalrus

Jupiter and a big disk.

IamtheWalrus

Blurrier versions.

ZeRoY

jfSDAS wrote: »

The publication of "Nightscenes 2013" has been delayed and I suspect it's because Paul is probably adding information about comet ISON, which is predicted to be prominent in our skies towards the end of 2013. See http://www.astrospace.co.uk/Astrospace/shop/publications.html for details. It's often stocked by Hodges Figgis in Dublin but can be purchased direct from Paul or on Amazon.

Got both the guide to AP and the Night Scenes 2013 and i have to say they are great little guide for the price, thanks again for the hint!

jfSDAS

Many thanks for posting up those pics of Jupiter with the Moon. You'll find yourself bitten by the astrophotography bug now

ZeRoy, cheers for the info about Paul's booklet being available now. I put in an order myself today.

John