How Many Stars Can We See?


I’ll never forsake stars, they’re as much who I am as the air I breath. A rural child, raised decades before electronic distractions – stars were my universe. A portal entered with nothing more than imagination. Mythology danced before my eyes – never forced, elusive or fleeting. Constellations made sense of history – I gazed upon stars just as ancients once looked to the cosmos for answers. Taken for granted my stars would never fade. Not until decades of emptiness met circumstance in the middle of night- a abandoned highway somewhere in Arizona, did I realize how I longed for my stars. Unfettered by light pollution – I welcomed lost stars.

Reality of light pollution – equal parts inevitable and devastating, led me to ponder how many stars we can see. The answer is – not many. Get away from urban illumination, give yourself half an hour or so adjusting to darkness – maybe you’ll see a few thousand. Deposit yourself in the middle of an Arizona wasteland, undoubtedly that number rises. The trouble is – few of us bother with Arizona nights.

Ponder the day when all who remember stars are gone, when no child rests on summer’s night grass becoming one with the ancients. Imagine not finding the North Star or plucking Orion’s belt from the sky.

San Francisco night sky as viewed without light pollution. – Thierry Cohen

Click on the link to view images of night sky sans light pollution images of 10 major cities by Thierrry Cohen…

http://www.smithsonianmag.com/science-nature/what-major-world-cities-look-like-at-night-minus-the-light-pollution-12087147/

 

 

 

 

The Great Bear


The Big Dipper needs no introduction – yet it crossed my mind, this celestial constant might deserve a little ponder. Often mistaken for a constellation, the seven stars – Alkaid, Mizar, Alioth, Megrez, Phecda, Merak and Dubhe – form an Asterism, or subset of stars within a constellation. in this case Ursa Major – the Great Bear.

In November, the Great Bear descends to the lowest point along northern hemisphere horizons. Micmac people of southeast Canada saw this as a sign “earthly” bears went into hibernation, and tree sap returned to the “womb of creation”. Ursa Major appears to touch the earth, winter takes full command. The great bear sleeps, her extremities falling below the horizon yet the Big Dipper manages to hover above the edge of perception.

The Big Dipper doesn’t come and go with seasons, it’s circumpolar, meaning it lies in the same direction as the celestial north pole.  A line drawn outwards from the pole would pass  practically through the Dipper, and intersect with Polaris (the North Star). Earth rotates on its axis around Polaris, stars that are circumpolar to the north pole travel in tight circles around Polaris, therefore visible all year, albeit with a few sways and dips. If the Big Dipper was a clock moving once around Polaris every 24 hours –  the “bowl” would always face Polaris – at 6 o’clock it would appear flat, 3 o’clock standing on the handle, 12 0’clock upside down, and 9 o’clock standing on the bowl.

Lay eyes on the Big Dipper, finding Polaris becomes a simple matter of locating the two outermost stars of the bowl (farthest from the handle) – draw an imaginary line up and beyond for roughly 5 times the depth of the bowl – voila, the North Star.

Think of the Big Dipper as a celestial guide – take comfort in understanding it will never allow you to loose your way. If you see it, you can find north. You don’t need to panic if your GPS craps out – celestial navigation won’t let you down.

http://www.theskyscrapers.org/getting-to-know-the-big-dipper

Image Credit: AlltheSky.com

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Make A Planisphere


The ridiculously difficult landing of Rosetta Mission’s Philae probe on comet 67P ignited pondering fires of cosmic wonder – a topic I’ve been silent on far too long. Months ago I wrote a post about “baby steps” to the cosmos, followed by several more on identifying specific stars, planets and constellations. Doubtful that many people bothered to follow meticulous instructions for visual orientation, my fall back has always been enthusiastic encouragement to download Google’s Sky Map app. As I pointed my phone at tonight’s sky, it occurred to me – this is too easy.  To”Google”, is to arrive at answers without the process of investigation. Sky apps are handy in a pinch, but rather like cheating on a final exam – how could I study for the test?

My mind drifted back to grade school, and it hit me – I’ll make my own Planisphere.

Planispheres have existed in one form or another for centuries – one disc over another, rotating on a central pivot. Or a “pocket” and “wheel” you slip into the pocket depending on where you are and what you want to see. I found the site linked below – step by step instructions for all your Planisphere needs. First you print a “pocket” based on your latitude, then you make “city” and “milky way” wheels. City wheels are basic orientation of the brightest objects as seen from your location. Milky Way wheels are full on representation of everything visible if you could view the night sky as if in a rural location, free of light pollution. The site gives latitudes and instructions for “traveling” star wheels – make Planispheres when you travel, or send them as Christmas gifts to anyone, anywhere.

Of course I could go out and buy a Planisphere, but that defeats the purpose. The point is to stop and think about your latitude, realizing it truly matters to the night sky. A Planisphere forces one to understand the cosmic drift and flow. Making one teaches far more than occasional posts or instant recognition Google ever could – a star wheel offers reasons, makes us think, and takes us back to the joy of discovery.

http://www.astronomyinyourhands.com/starwheel/starwheel.html

 

Regulus Occultation


Regulus is considered the 20th or so brightest star visible from Earth. A measly 77 light years away and part of the constellation Leo – Regulas couldn’t be easier to find. With apologies for the late notice – residents of New York State, Connecticut, New Jersey, Ontario, Manitoba and Nova Scotia ( assuming clear skies prevail ) bundle up around 2 AM for the Regulus occultation.

Shortly before 2 Am head out and find the moon – extend your arms and voila! – Regulus is the brightest object above your right hand, roughly the same height as the moon and certainly the brightest object in that corner of the sky.

Looking southwest, 2 a.m.

Looking southwest (90° to the right of the Moon) around 2 a.m. EDT on the morning of March 20th. Regulus will appear roughly as high as the Moon. It’s the brightest star in the area; you don’t need to know, or see, the constellations! Click image for larger view.
IOTA / Stellarium / Sky & Telescope
At 2:06 AM EDT asteroid 163 Erigone will pass Regulus – completely blacking it out for 14 seconds. An unprecedented asteroid occultation, never witnessed let alone observed by the naked eye in North America.
If nothing else, remember to look up the next clear night to familiarize yourself with a shining star. Dazzle your friends when pointing out constellation Leo, astound them when identifying Regulus , and tuck that nugget of star power under your belt.

Sky Map-Ponder the Mystery of the Night Sky


This is a shameless plug for the Google Sky Map app. If you have an android phone, download this one immediately. Hold your phone up at the night sky and it tells you exactly what stars or constellation you’re looking at. You can search for constellations, specific stars, planets, or meteor shower. It will make an astronomer out of you.

http://support.google.com/maps/bin/answer.py?hl=en&answer=91511

Once you’ve downloaded, the link above is great for learning how to use all the features. It’s very, very easy

Strain and you may find Andromeda


Andromeda, the nearest galaxy to our own, is the farthest  point in the night sky, visible to the human eye. Andromeda, 2.5 million light years away, guaranteed to set you pondering once you’ve trained your eye to settle upon this wonder. The link below is lots of help if you don’t know where to look for it.

http://www.constellation-guide.com/constellation-list/andromeda-constellation/

Messier 31 – Andromeda Galaxy

andromeda galaxy,m31,messier 31,spiral galaxy

Dog Days of Summer


The expression ” dog days of summer ” originated in ancient Rome. The Romans noticed that between July 3 -August 11, the star Sirius joined the sun at sunrise, appearing to become one. They believed this added to the extra warmth in the hottest days of the year. Sirius, the brightest star in the sky after our sun, belongs to the constellation Canis Major, known as Big Dog or the Dog Star. Because the earth wobbles on its axis these days are no longer precise, in America Sirius doesn’t “join” the sun until August 4 – Sept. 11. The hottest days of the year are still referred to as the “dog days”.

.http://suite101.com/article/the-dog-days-of-summer-a60376

photo.

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Photo from Flickr – Alexandra J.S.