View the Twinkling Dog Star with your Celestron NexStar!

Mar 16 • News • 7837

Last night, while walking my dogs, I took a moment to gaze at the stars overhead.  Outside Chicago, there’s a lot of light pollution, which makes it challenging at times to make out more than a few constellations, but you can generally make out some of the major ones.  The Big Dipper, Orion’s Belt and a few other notable constellations are easy to spot, but my favorite has to be Canis Major.

Canis Major, as the name implies, looks like a dog.  Appropriate that my eye would be drawn to it as I walked my two pooches, but there was another reason for my attention centering on this constellation: Sirius.  No, not the satellite radio company.  Rather the star it draws its name from.  Sirius is the brightest star in the night sky.  Because of this it also twinkles more than most.  The flickering light drew in my eye the same way that a laser sight with a pulsating mode draws in your eye.  It’s a somewhat unnatural image, so you eyes will naturally be drawn to it.  The science behind this is used by companies like LaserMax for their Guide Rod Laser Sights.  On a diverse background, such as dense foliage, your eyes will be able to pick up the laser far more quickly than they would a steady dot.

This same effect makes Sirius really pop out amongst the other stars.  As I looked at it, I wondered about the twinkling.  Why, for that matter, does any star twinkle?  Thus an investigation began!

To begin, a bit more info on Sirius.  It is the brightest star in the sky for a few reasons. First, it puts out a lot of light (duh).  As a binary star, there is actually a little star next to what we think of as Sirius.  The little sister star is called Sirius B.  The amount of light put out by Sirius and Sirius B has an absolute visual magnitude of 1.42.  I’m betting many of you are with me in that you don’t understand what that means.  The easiest way to think of an absolute visual magnitude of 1.42 is that this is 25 times brighter than the sun!  When combined with the proximity of Sirius, which is only about 8.6 light years from Earth, you get the brightest star in the sky.

The brightness of Sirius actually contributed to its name, which is from the Greek word for scorcher or glowing.  Other nicknames for the star relate to its inclusion in Canis Major.  You may have heard Sirius called the Dog Star or Canicula.  It’s really interesting to note that a wide variety of cultures, many of which had little to no contact with one another, have seen Canis Major as a dog.  Many constellations look different to different groups of people, but Canis Major is fairly consistent in its dog-like appearance.

So we know why it’s bright, but what makes Sirius twinkle?

It’s not the star itself, but the path its light takes getting here. Like the light you see from every star, the light from Sirius has to pass through a great deal of different substances on its way to your eye.  While there may be clouds out in the cosmos that light passes through, the bulk of these substances are in Earth’s atmosphere.  Anyone who has ever seen a weather report knows that various gasses are constantly swirling about right above our heads.  Even on a clear night, there is a great deal of oxygen, nitrogen, hydrogen and more between you and the stars.  These gasses cause the light to bend slightly, and as they are constantly moving, the bending light is also constantly changing.  This causes stars to twinkle.

Sirius seems to twinkle more than others for two reasons.  First, as mentioned above, it is very bright.  The brighter a light source, the more obvious its twinkling will be.  The other reason Sirius twinkles so much is its placement in the sky.  The Dog Star is fairly close to the horizon.  A star that’s directly overhead will have the least amount of atmosphere between you and it, but the light from a star further down has more atmosphere to travel through, so the light bending effect is more pronounced.

I’m hoping for another clear night soon so I can take a telescope out and get a better look at the Dog Star.  The Celestron NexStar 4SE Telescope would be a fantastic option, as it has amazing lenses and an incredibly easy to use computer system that helps you find what you’re looking for.  It can be a real hurdle for amateur astronomers to find various stars, constellations and other celestial objects, so having a computer do some of the heavy lifting really makes things simpler and more fun.  You shouldn’t have any problems finding Sirius if you’re using the NexStar Telescope, so have a great time.  Spring is starting, enjoy the warmer weather this evening by pondering the mysteries of the universe with a great Celestron Telescope!

OpticsPlanet • 4 Comments on View the Twinkling Dog Star with your Celestron NexStar!

Scope out the Night Like the Pros with Pulsar Digisight Night Vision

Mar 14 • News • 4446

Night Vision is becoming more and more ubiquitous these days.  While the technology was initially intended for military use alone, it has evolved over the years to give rise to greater functionality.  Thanks for technological advancements and user ingenuity, there are more uses for night vision than ever.

For instance, I’ve been reading about how helicopter pilots are using night vision to both increase safety and aid in search and rescue operations.  The first story focused on CALSTAR (California Shock Trauma Air Rescue) which has a handful of night vision devices both for the pilot as well as for nurses and medics on board.  CALSTAR is a nonprofit air ambulance service which aims to both save lives and reduce trauma by transporting patients to proper medical facilities as quickly as possible.  They are often called upon to transport an injured hiker, camper or hunter at night, so they need to be able to land a helicopter amongst trees and other possible hazards in the dark.  Once upon a time they would have tried this without night vision.  Fortunately, those days are gone.  If for some reason their night vision is not operational, they don’t make the trip.  A single tree can be nearly impossible to see in the dark, and even a bit of fog or other inclement weather can make these trips too hazardous to risk.

With night vision a pilot can immediately make out ridgelines, or the top edge of mountains in the area, which enables them to accurately chart their course.  Both on the ground and in flight, medics are far more effective when they have night vision goggles.

Another story I read related the account of a search and rescue pilot who was able to see a lost hiker because of night vision.  The hiker was lost in the woods for several hours and didn’t have overnight supplies.  Though he had a phone on him, he didn’t have a GPS device, so he called home to let his family know of his predicament.  They called the police for help.  The hiker had a headlamp on, which was clearly visible to night vision even from high above and through dense tree cover.  There was little chance the pilot would have spotted the man if he hadn’t been wearing night vision goggles, which amplified the small amount of light from the hiker’s headlamp.  The man was cold but otherwise uninjured.  He would have had a long night if not for night vision.

I realize most of you aren’t planning on piloting helicopters at night anytime soon, but the uses for night vision are so varied that there’s a unit for everyone, from helicopter pilots and soldiers to hunters who need top quality without breaking the bank.

Case in point: one NV unit I really like is the Pulsar Digisight N550.  It’s incredibly tough, which it would have to be, as it’s a night vision rifle scope.  Pulsar designed the N550 to easily handle recoil, but the quality of this awesome NV Rifle Scope comes from more than just durability.  Unlike traditional night vision devices which use a photocathode tube to intensify light, digital night vision use a charged-coupled device (CCD), which provides a crisp, clear image from edge to edge of the scope.  That’s a huge improvement, and the detection range is far greater than most lower generation night vision devices.  The Digisight has a maximum detection range of 400 yards! When aiming, you can switch the reticle from black to white to better line up your shot, and if you don’t like the reticle style you can connect this Pulsar NV Scope to your computer and download a different one.  Imagine being able to modify your reticle quickly and easily based on your preference for a particular hunt!  Couple that with 4.5x magnification and this scope gives you an unbelievable value.

So what are you going to be hunting with the Pulsar Digisight?  Well, if you’re hunting in Texas I’m betting you’ll do a little hog hunting at some point, and these days you’re going to have to hunt them at night.  Hogs are one of the smartest animals in the world, and over the last twenty years they’ve learned to move around more at night because it’s more difficult to hunt them in the dark.  They’re so clever you’ll need every advantages you can get when hunting them.  Just like a helicopter pilot searching for a lost hiker or avoiding trees during a landing has a much better chance of success when using night vision, you’ll be far more likely to make your shot when you have a great NV Scope like the Pulsar Digisight on your rifle.

OpticsPlanet • 4 Comments on Scope out the Night Like the Pros with Pulsar Digisight Night Vision