Comet NeoWise Visible in July

Comet Neowise is bright and now easy to see.  I took this photo by Ft. Steele on Tuesday morning at 1:30am.  To see the comet, I’d recommend to go between midnight when it gets fully dark, until 3:30am when the Northern sky brightens with dawn.  Otherwise the faint streak of the comet is difficult to see against the glowing sky.  Binoculars make it brighter and allow you to see the pale-blue ion tail and pale-yellow dust tail, but it’s clearly visible by eye.

Neowise 2020 Jul 14 from Fort Steele, BC
Comet Neowise July 14, 2020 from Fort Steele BC

The photo shows Comet Neowise, looking North from Ft. Steele on Tuesday around 1:30am.  Lakit Mountain to the bottom right side with constellation Auriga hidden behind it, Capella the bright star there.  It was taken through a 28mm wide-angle lens.  The green glow along the horizon is the Northern Lights, which were slightly active that night.  According to NOAA, on their 9-point Kp scale it was a minor geomagnetic storm level 3.

Comet Neowise, Thurs Jul 16 at 2am from Fort Steele BC.
Comet Neowise, Thurs Jul 16 at 2am from Fort Steele BC.

Here’s the comet two days later, on Thursday morning at 2am.  Looking at the background stars, notice it’s shifted slightly upwards and to the left from the first photo.  Photographed with a more sensitive 28mm f/1.8 lens.  The comet looks a bit brighter, a white nucleus at bottom, with a pale-blue ion-jet going straight up, as well as a wide pale-yellow dust tail curving back.  Again, along the bottom right you can see Lakit Mountain with trees silhouetted in the red glow of the lights of Ft. Steele.

Comet Neowise Jul 16 zoomed in with 210mm Lens.
Comet Neowise Jul 16 zoomed in with 210mm Lens.

To take comet photos you’ll need about a 10 to 20 second exposure with a SLR camera on a tripod.  (A cell phone would be a challenge.)  This magnified photo was taken on a motorized equatorial tripod so the stars don’t make streaks as the Earth rotates.

Info about Comet NEOWISE C/2020 F3

Location: It’s currently on the Northern horizon, to the left of the constellation Auriga, in Lynx, and will slowly move higher and to the left through the feet of Ursa Major (beneath the Big Dipper asterism) over the next few weeks. It went around the Sun on July 3, inside the orbit of Mercury at 0.29 AU and it’s now moving out and away.   It will be closest to Earth within 64 million miles (103 million kilometers) on July 23.

The comet’s tail: The tail generally points away from the Sun.  (It doesn’t trace out the orbital path the comet is taking as many people assume, sometimes (after perihelion) the tail can point in the opposite direction that it is going.)  The Coma: is created when the heat of the sun melts the frozen ices and dust of the nucleus, which evaporates and lifts off the surface into a globular fog around the ice and dirt. There are various ices: water ice (H2O), dry ice (CO2), carbon monoxide (CO), methane (CH4) and ammonia (NH3). Carbon monoxide ionizes the easiest.   The Ion Tail: is the thin vertical pale-blue straight line in the photo, which is made up of carbon monoxide gases ionized by the Sun’s intense UV light and is pushed directly away from the Sun by its solar wind, along the Sun’s magnetic field streamlines.  It’s a very hot plasma that glows with a pale-blue light.  Sodium Tail: not visible in the photograph, it has a red separation in the tail caused by high amounts of sodium, which also ionizes easily.   Dust Tail: The broad and fuzzy curved pale-yellow tail in the photo. These dust grains and sublimated ice vapours (like steam) are pushed away from the coma by the Sun’s slight radiation pressure.  The dust tail curves as it is pulled by gravity along the orbit behind the comet, and smaller dust grains get pushed faster by sunlight than the bigger and heavier dust grains. The vapours and dust reflect the bright sunlight.  The comet is losing hundreds of kilograms of material every minute and will get smaller as weeks go by.  It should remain visible for a few weeks.

Why the name NEOWISE C/2020 F3?  The comet was discovered by NASA’s orbiting space telescope, the Near-Earth Object Wide-field Infrared Survey Explorer, or NEOWISE, on March 27, 2020.

How big is it?  NASA says: “From its infrared signature, we can tell that it is about 5 kilometers [3 miles] across, and by combining the infrared data with visible-light images, we can tell that the comet’s nucleus is covered with sooty, dark particles left over from its formation near the birth of our solar system 4.6 billion years ago,” said Joseph Masiero, NEOWISE deputy principal investigator at NASA’s Jet Propulsion Laboratory in Southern California.

Location of Comet Neowise plotted until July 26
Location of Comet Neowise plotted until July 26
I made up this skychart in Cartes du Ciel using data from the minor planet  In the starmap you can see Ursa Major (the Big Dipper) at upper left.  The comet drifts left along the feet of Ursa Major.  It should remain visible along the Northern horizon until Jul 26.

If you get a chance, take 50mm binoculars and try to spot the pale-blue ion tail and the pale-yellow dust tail.  Otherwise it’s clearly visible by eye for a few weeks.

Rick Nowell

2017-8-21: Solar eclipse of Monday, Aug 21, 2017

SOLAR ECLIPSE TIME max lasting for about 2min over Vancouver, to 2min 17sec as you go to Eastern BC.

Here are times for cities across BC and Alberta. There are four numbers: the local times for the start, maximum and end, and the maximum fraction of the solar diameter covered: Victoria (09:08, 10:20, 11:37, 91%), Vancouver (09:10, 10:21, 11:37, 88%), Penticton (09:13, 10:25, 11:42, 87%), Cranbrook (10:16, 11:30, 12:48, 85%), Calgary (10:20, 11:33, 12:50, 81%), Edmonton (10:24, 11:35, 12:49, 75%).


TELESCOPE: if you setup a telescope (with a solar filter and video camera) the Sun should be seen safely on a video display.  We may see sunspots at the centre of the disc, even though the Sun is nearing sunspot minimum.

SPEED OF THE MOON’S SHADOW:  If it’s hazy with forest fire smoke, try going 7000 feet up a mountain to get clearer views.  From a mountain top, I wonder if I’ll be able to see the shadow of the Moon sweeping in from the West?  Over Eastern BC, It’s approaching at around 3,000 km/h; or 0.833 km/s.  That’s 2.5x the speed of sound, so a military jet could keep up with it, but a car can’t.  The totality shadow will be about 109km wide, and take just over 2 minutes to pass.  Source:

PATH OF TOTALITY: The Map of totality below shows you’ll have to go 500 km South of the US border to Salem, Oregon or to Idaho Falls in Idaho to get the full effect.

Map by Xavier Jubier.  http:\\

ECLIPSE GLASSES:  So, where to get adequate eyewear, sunglasses won’t do!  You can send away for cardboard eclipse glasses (mine haven’t arrived yet), but be sure they are very dark, like shade 14.  Try getting some welders replacement lenses; again, shade 14 is safest.   They are rectangular glass plates, about 4” x3” x2”.  They should be available locally at Air Liquide, or Acklands, or other welders supply place (unless they are already all sold out).
EYESIGHT WARNING: When you look at the Sun, the lens in your eyeball acts as a burning glass, and the target is the back of your eye, where imaging happens. You can also damage the protein jelly, or “aqueous humour” that fills your eyeball. The damage can be permanent. Staring at the Sun using a telesc​ope or binoculars that have not been modified for solar observing could likewise lead to permanent damage. A pair of 10×50 binoculars (10 times magnification, 50mm objective lenses), will collect between 50 and 100 times the amount of light and heat that your eye lens will collect. Permanent damage will be near instantaneous. There is specialist hardware that can be used with telescopes and binoculars that make them usable for safe solar observing. However, unless you are completely familiar with these devices and how to use them… DON’T. If you are not an expert then go find one.”  Quote from Ken Tapping, astronomer at Penticton, BC.

SOLAR PROJECTION: (adults only please) using a spotting scope or binoculars (or a magnifying glass).  Set it up on a tripod, and focus the telescope at infinity (a mountain first).  Then hold a white square of cardboard about a foot away from the eyepiece, or against a white wall (some telescopes come with a little arm and clip for this purpose).  The cardboard should be in a shadowed area.  Be careful not to look through the eyepiece of the scope (or the finderscope!)–just look at the shadow of the scope on the ground to point it at the Sun.  Centre the image of the Sun on the white card.  Move the cardboard close for a smaller/brighter image; and further away for a bigger/dimmer image. That way you get enough magnification to see sunspots too. (Galileo pioneered this projection technique back in 1612.  He didn’t go blind until he was 72, and that was from cataracts.)

FIRE AND BLINDING DANGER: Don’t hold the cardboard too close or you’ll burn a hole through it.  Don’t try to look through the eyepiece,  or you’ll burn a hole in your eye’s retina.  Don’t goof-up or you’re permanently blind.  Watch out for kids around you.  Don’t leave unattended.  Don’t burn your finger or start a fire!  (That said, I did this in grade 11 astronomy class and nobody had any trouble.)