Blog Archives

Eyes on the Sky: June 11 thru June 17

How to find EVERY planet in the solar system this week! Find Mercury, Mars and Saturn in the evening sky, and Neptune, Uranus, Jupiter and Venus in the morning sky.

Neptune& Uranus Finder Chart: CLICK HERE (5.4 MB)

There is also a wide-field and narrow-field chart available from “Sky and Telescope” magazine, here.

Pluto finder chart: CLICK HERE (6.8 MB)

More detailed chart to magnitude 14.5: Click here (opens new window to different website – the top two “TYC” stars identified are the same two “HIP” stars identified in my chart, above, and in Stellarium)


Related articles

Eyes on the Sky: June 4 thru Jun 10

Two Sun/Earth alignments, and plumbing the depths for Pluto

This week’s “Eyes on the Sky” details who is best situated to see the lunar eclipse of June 4, how nearly everyone worldwide can watch the Venus Transit of June 5 (or 6th, depending on your location in the world – also see links below last week’s video), as well as a really difficult challenge: PLUTO!  This 14th magnitude icy body revolves around our Sun at nearly 3 billion miles distance; can you spot this tiny, dim speck in Sagittarius?  This week’s video shows you how to learn the area it’s in, some fantastic clusters you can see easily even with binoculars from light polluted areas, and when to look to try and find the 9th plan…. errr – previously-the-9th-planet.  (See link to PDF finder chart, below).  Check it out, and “see what’s up” in the sky this week.

Pluto finder chart: CLICK HERE (6.8 MB)

Eyes on the Sky: May 28 thru Jun 3

Venus Transit: Transit lunar craters, transit history, and more

The Transit of Venus across the face of the Sun only occurs twice every 100+ years.  On June 5/6 (depending on where you are in the world; it will be on the 5th in the United States), the last chance humans will have to see the disk of Venus transit across the face of the Sun will occur.  Accurately calculating the times the transit occurred in the past helped astronomers hundreds of years ago to calculate the distance from the Earth to the Sun, also known as the Astronomical Unit (AU).  Because these transit viewings and calculations were so important to understanding the size of our own solar system, quite a few craters on the Moon have been named after astronomers of the past involved in these efforts.  This week’s video takes a look at some of these craters, astronomers, and prepares you for this last-in-our-lifetime transit.  Check it out, and “see what’s up” in the sky this week.

Lots of links about the Venus Transit

For times and dates of when you can see the transit, click here.

Eyes on the Sky’s solar safety video can be seen here, along with ways to make safe solar viewing equipment.

Charts for finding/viewing the Horrocks/Halley craters on the Moon: COMING SOON

Thread by Paulie about Venus Transit lunar craters at Chicago Astronomer site.

For a lot of wonderful information about the transit, see

Here’s how to safely photograph the transit.


Eyes on the Sky: May 21 thru May 27

Two crescents on the 22nd; Hunting in the Dragon

With the Venus Transit just a couple weeks away, the brilliant point of light in the western sky is sinking towards the horizon.  And given the recent solar eclipse seen by much of the Pacific area of the world on the 20th, the Moon is just past new, and pays a visit to the planet.  Check out how these two crescents can be seen easily from most any location.

Looking to the north, we find the constellation of Draco the dragon.  Though dimmer overall than many of the more prominent constellations, it’s location near the Big Dipper and the bright star Vega means that we can go hunting for some interesting objects with binoculars and telescopes.  For a star charts of the Draco region, click here and download Star Charts #1 and #6.  And don’t miss Saturn near a couple of brighter stars in Virgo, neatly framed in a wide-field telescopic view.  Check it out, and “see what’s up” in the sky this week.

Related articles

Eyes on the Sky: May 14 thru May 20

Binocular binaries in Bootes; May 20 solar eclipse

Last week’s video showed a number of double stars that can be spotted in the “ice cream cone” shaped constellation of Bootes, the Herdsman.  This week there are more double stars to see there – all of them easy, and all can be seen naked eye or with binoculars.  Check out these great color-contrast objects this week.  And on May 20th, an annular solar eclipse will occur, and many in the western United States will have a chance to view parts or all of it.  Be sure to see the week’s “Eyes on the Sky” for when to view it, and how to view it safely (DO NOT look at the Sun directly during the eclipse!).  Wishing you clear and dark skies (well, except for the eclipse)!

You can find more information about the May 20 solar eclipse on NASA’s website.

View the solar eclipse safely by making a simple pinhole solar viewer.

Related articles

Eyes on the Sky: May 7 thru May 13

Eyes on the Sky: May 7 thru May 13

Mars and more Messiers; Bootes doubles up

Mars makes moves heading out of Leo starting this week, but not before it gives us one last pointer to the Leo Triplet of M95, M96 and M105.  Faint galaxies all, but worth attempting if they have been difficult to find previously for you.  If that challenge is a bit too much for your skies, take a whirl back over to Bootes, and see “double” with some double stars lurking in the Herdsman.  Wishing you clear and dark skies!

Free Lecture 03: Universe Scale, and Light II

The lecture video is embedded below but also available here in MP4 format.
Additionally, slides used in the lecture are embedded below but also are available here in Powerpoint format.
Questions after the lecture? Please ask them in here.

Wikipedia entries:
Black body
Spectral line
Bohr model
Doppler Effect

Additional Apod photos disccussed

Imagine if we lived in a binary solar system or a triple star or even an open cluster with 10-100 stars or  why not a globular cluster with 100000-1000000 stars….. But don’t we see that we live with one bright star, which is kind a bit unusual, but it rather appears that it is the greatest benefit to humanity, allowing us to have a Night.

The Bohr atom

The Doppler shift high and low

Sheldon Doppler

Eyes on the Sky: April 30 thru May 6

Eyes on the Sky: April 30 thru May 6

Venus at brightest; a celestial time trip(let)

Venus will be taking center stage in about a month when it transits across the face of the Sun for the last time in 105 years.  But it manages to steal the spotlight by outshining everything else in the sky except the Sun and the Moon.  Learn how to spot its phases with a a telescope, or catch the brilliant planet’s dazzling glow near a fairly bright star in Taurus, which will look quite dim in comparison.

Later in the week, the nearly Full Moon glides by Saturn and Spica.  These three objects are vastly different distances from each other, and contemplating the time differences of light from each is a pretty cool exercise to consider.  Use a telescope to spot Saturn’s rings.  Wishing you clear and dark skies!

How to find the Winter Hexagon


Orion is the key for
cracking the winter sky

The winter sky is an excellent place to begin exploring the constellations that make up the night sky. Orion is the key, or signpost, for locating many of the other constellations in the winter sky. There are two convenient ways to locate all of the main constellations around Orion once Orion is located. Fortunately, Orion is easy to locate and well known to most people.

The first way is to follow lines made by pairs of stars in Orion. The second way is to locate the great winter hexagon of bright star around Orion.

The Constellations of the Winter Sky

If you live in the northern latitudes and you scan the sky from the southern horizon to the region overhead, you should be able to see the following constellations on a clear winter night: Orion the Hunter, Canis Major the Great Dog, Canis Minor the Little Dog, Taurus the Bull, Auriga the Charioteer, Gemini the Twins and the Pleiades star cluster. (See the map on the next page).

 In Greek mythology, Orion was a great hunter who eventually offended the gods, especially Apollo. Apollo tricked Artemis, the Goddess of the hunt, into shooting Orion on a bet. When she discovered that she had shot Orion, she quickly lifted him to the heavens and made him immortal, where he now hunts eternally with his two dogs, Canis Major and Canis Minor. In front of him is his prey Taurus the Bull.

 The myths surrounding Auriga the Charioteer vary, but it is an ancient constellation dating back to at least to the Ancient Greeks. Some say Auriga invented the chariot and others that he trained horses for the best chariots.

 Gemini is a constellation made up of two stick figures known as the twins, Castor, who was a great horseman, and Pollux, who was a great boxer. According to one myth, Castor and Pollux (a.k.a. Polydeuces) were the sons of Zeus and Leda (from Leda and the Swan) and were hatched from an egg. Their sister was the beautiful Helen whose face launched a thousand ships to do battle in front the Trojan city of Troy.

Method 1: Using Pairs of Stars in Orion as a Guide

Finding Sirius and Canis Major

If you follow a line from the belt stars of Orion to the left and slightly down, you will come across a very bright star called Sirius, which is also known as the Dog Star. (See the arrows in the diagram to the right).

Sirius is the brightest star in the night sky so it is hard to miss. Once you’ve located Sirius you can locate the other stars in the constellation Canis Major the Great Dog.

Finding Procyon and Canis Minor

Follow the a line from the shoulder stars of Orion to the left. The first bright star that you will come close to is Procyon, which resides in Canis Minor.

From there you should be able to see the other star that us easily visible. Together, the two stars make up the constellation Canis Minor, which is also known as the Little Dog. Along with Canis Major, Canis Minor follows Orion across the heavens on an eternal hunt.

Finding Aldebaran and Taurus

Following the belt stars to the right, you will pass just below the bright star Aldebaran and through the constellation Taurus, which is also known as the Bull.

Continuing on you will run across a fuzzy blur of stars closely grouped. These are the Pleiades, or the Seven Sisters.

Finding Capella and Auriga

Follow the bottom most star on the left and the left most belt star upwards (going roughly over your head) and you will come across a very bright star called Capella. From Capella, you can follow the pentagon of brighter stars nearby that make up Auriga. Just below Capella, there is a triangle of stars known as ‘the kids’ as in goat babies.

Capella was one of the most important stars for navigation as it could be seen throughout most of the year from mid northern latitudes.

Finding the Twins Castor and Pollux

Follow a line from Rigel to Betelgeuse heading upwards and overhead. You will come to two rough sticks of stars that are headed by two brighter stars. This is the constellation Gemini, composed of the twins Pollux and Castor. Pollux is on the left and Castor is on the right.

Method 1: Using the Winter Hexagon Centered About Orion

If you look in around the sky centered on Orion, you should be able to see a rough hexagon of very bright stars. This is called the Winter Hexagon. Starting at Rigel, if you go counterclockwise by one, you end up at Aldebaran in Taurus. Go counterclockwise once more and you end up at Capella in Auriga. Go counterclockwise once more and you end up at the pair of stars Pollux and Castor in Gemini. Go counterclockwise once more and you end up at Procyon in Canis Minor. Finally, if you go counterclockwise once more you end up at Sirius in Canis Major.


The winter hexagon v/s the summer hexagon?

Credits : Winter hexagon - Felgari

The winter hexagon is not a constellation but simply an asterism. But when there’s winter in the Northern Hemisphere, its summer in the Southern Hemisphere. I find it really unfair for the world to call this set of stars as the winter hexagon. Why don’t call it the summer hexagon? Frankly speaking I feel like being discriminated on belonging from the Southern Hemisphere.

Winter Hexagon from the Tropics

I understand that development in the astronomy field knew its leap in the Northern Hemisphere, but still I am hereby campaigning for a change in the name of this asterism ( I know Asterisms are not even officially recognized names). But the “winter hexagon” It is a complete misnomer. When I first got to see this beautiful set of constellations in its entirety by the seaside, I was feeling hot. One as it was a breezeless night, hot and damp. Secondly for the utter pleasure of being able to identify the hexagon which covered almost ¼ the portion of the sky and being able to identify six constellations in one go.  It was awesome.

But Do you Know How to find the winter hexagon?

One could ask it’s already April and the spring is already here, so why talk about the winter hexagon? It’s just because the winter hexagon in a few months would not remain in our skies. During January at dusk I would have to raise up my head towards the zenith to see the Orion as it would highlight our north western skies, but now in April it’s already halfway between the horizon and the zenith towards the west at dusk. And to tell you Scorpion is already on its way. (Hope you know about the Scorpion – Orion saga) So to say in a few months Orion would be no more on the skies. (I would miss Orion a lot)

And as April is here, it would be a lovely time to appreciate the nature in its bloom and a have good time to observe the night sky. No more shivering and complaining about the chilly weather to have a look at the sky (for my friends of the Northern Hemisphere). As for us Mauritians, we have only two seasons per se. Our hot humid summer is already gone and we are slowly entering the winter phase.

So, if you feel being discriminated by pronouncing the Winter Hexagon, (or any other misnamed constellation or asterism) then campaign with me for this misnomer. Together, united we can change the name of this marvelous hexagon to a common name. Because as the saying goes “the sky has no borders, it is for everyone”. (Is it really a saying or I just made it up?). I suppose I got it from The Astronomers without borders. They have their motto as One people, One Sky.

Related Articles:

How to find the winter hexagon

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