The Stargazing Almanac

for March 2020

By the Street Astronomer

March

March is the 3rd month of the modern calendar, but the first month of the old Roman calendar. So initially, the Roman year began in the spring with March. March was named after Mars, the Roman god of war, which was Martius in Latin. So why Mars? Because the Romans considered Romulus and Remus to be the founders of Rome and their father was Mars.

On March 1st, the sun rises at 7:22 AM and sets at 6:33 PM. And on March 31st, the sun rises at 6:29 AM and sets at 7:10 PM. These times are for Boise, Idaho.

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The five visible planets reside in the following constellations this month.

Mercury: Aquarius (morning planet)

Venus: Pisces, Aries, and Taurus (evening planet)

Mars: Sagittarius and Capricornus (morning planet)

Jupiter: Sagittarius (morning planet)

Saturn: Sagittarius and Capricornus (evening planet until midmonth)

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Adhara

This month look for the star Adhara in the constellation of the Big Dog, Canis Major. Canis Major has two fairly bright stars; with its brightest, the most brilliant star in the sky. The next brightest star in the constellation is Adhara. If it weren’t for nearby brighter Sirius, Adhara would stand out as a reasonably bright star on its own. Astronomers call Adhara Epsilon Canis Majoris.

Adhara is 432 light years away from Earth. That means the light we see tonight left in the year 1588. Since Sirius is just less than nine light years away, Adhara is 50 times further away from the sun than Sirius. If Adhara were as close to us as Sirius, Adhara would appear seven times brighter to us than it does now. This means that if we viewed them from the same distance, Adhara would appear more than twice as bright as Sirius.

Its spectrum indicates that Adhara has a surface temperature of 36,000 degrees or nearly four times hotter than our sun. Including its ultraviolet radiation, Adhara emits 15,000 times more light than the sun. It’s this luminous because Adhara is 12 times more massive than our sun (greater mass causes a star’s hydrogen fuel to fuse faster). If Adhara replaced our sun, we’d have a new sun that was 13 times larger and over 3,000 times brighter. Needless to say, we couldn’t live on the Earth if it orbited Adhara.         

Look for Adhara tonight. It’s the lower right star in Canis Major. You’ll find the Big Dog almost due south at 9:00 PM in mid-March.

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The moon appears near the Hyades and Pleiades star clusters on the night of the 1st. Both star clusters are ideal targets for your binoculars since they’re so large and bright. People can often see the Pleiades in city skies. The brightest star of the Hyades is also visible, even if the rest of the star cluster is not visible to the unaided eye. But the rules change with binoculars. In fact, a telescope is too much to use on these star clusters on account of their extended size.

The moon’s first quarter on the afternoon of the 2nd. This is one of the most perfect lunar phases because it makes seeing lunar craters and mountains so much easier. So point your binoculars at the moon on the night of the 2nd. Focus most of your attention along the boundary between day and night (the terminator) and enjoy the view.

 

Also on the night of the 2nd, the first quarter moon is located just beyond the boundaries of the Hyades star cluster. Look to the right of the moon and you’ll see the bright star, Aldebaran. Aldebaran is not actually a member of the star cluster. It’s a foreground star, or one that lies closer to our solar system than the star cluster. The Hyades represents the face of Taurus the Bull and Aldebaran his eye.  

The moon pulls alongside Gemini the Twins on the 5th. That night you’ll see the brightest star of Gemini, Pollux above the moon and his slightly fainter twin, Castor higher still. The Twins appear horizontal in the winter and early spring. By summer they will have rotated to the western horizon and stand vertically.

The moon is only four degrees away from the Beehive star cluster on the 6th. Four degrees is close enough that both the moon and star cluster appear together in a pair of binoculars. The Beehive is different from either the Hyades or Pleiades. It’s moon-sized and packed with about two dozen stars. It takes the magnification of a small telescope better than the Hyades or Pleiades, too. So aim your binoculars at the moon and then move the moon just outside your view in the 8:00 position. The Beehive will appear near the center of your binoculars’ view.

For stargazers wanting to identify Leo the Lion and its two brightest stars, the 7th is your night. The moon appears above Regulus, the brightest star and heart of Leo. The five stars above Regulus form a backwards question mark with Regulus and represent the back of his head and mane. At the eastern end of Leo is its second brightest star, Denebola. This star represents the base of Leo’s tail. The other two stars forming a triangle with Denebola are the lion’s hindquarters.

The third full moon of the year is the Sap Moon and it occurs on the 9th this year. A day later, the moon will be at perigee or where its orbit brings it closest to Earth. That means the moon will appear larger and brighter than average. You probably won’t notice the difference with a typical full moon and a Super Moon. However, you can take a picture of this month’s full moon and compare it to the full moon in September. If your camera settings are the same (zoom, exposure time, and ISO), the difference between the two full moons will be noticeable. Use a camera tripod when taking your picture so that the camera doesn’t shake. Also, try several different camera settings to find one that works well. Don’t forget to record your settings as you probably won’t remember them six months from now.

The moon reaches last quarter phase on the 16th. When it comes to viewing through binoculars, last quarter is as good as first quarter. Except that you must go outside after midnight. Well, it’s not quite that easy as the 16th is a Monday morning. It would be far easier to observe this moon if it occurred over a weekend. Nonetheless, along the terminator, or straight edge of the moon you’ll see lots of craters in the moon’s Southern hemisphere.

In the Northern hemisphere of the moon are lunar maria (Latin for sea) or seas of frozen lava. The maria are rimmed with mountain ranges. Both craters and mountains cast strong shadows at first and last quarter for stargazers on Earth.

The 18th is a spectacular morning for observers of the moon and planets. That morning the moon will appear near Mars, Jupiter, and Saturn. Therefore, this will be a perfect morning for learning how to identify these three planets. The planets except for Jupiter are too small and distant to show detail through binoculars. Jupiter, however, shows a disk and several of its satellites. The relative position between these satellites and Jupiter changes every day. So it’s definitely worth looking observing Jupiter regularly.

On the morning of the 19th, the moon will have passed yesterday’s planets and appear in a neat line with all three. Observing the moon will be possible starting around 5:30 AM, depending how low and clear your southeastern horizon is.

Spring begins late night of the 19th.

Mars and Jupiter are drifting pass each other and will appear their closest on the morning of the 20th. The distance between Mars and Jupiter will be ¾ of a degree, or 50% wider than the apparent diameter of the moon. Mars, Jupiter and Saturn will be so close together that you can see all three at the same time in a common pair of binoculars.

Stargazers will find the Evening Star or Venus at its highest elevation above the western horizon on the night of the 24th. Venus is so bright that you can’t miss it. Sadly, Venus is too small and distant to show any detail through binoculars most nights. A small telescope can show its phase. However, its glare makes this difficult to see if you observe it after dark.

The moon is new on the 24th. It will be a few more days before you see it again.

Check out the waxing crescent moon on the evening of the 28th. The four-day old moon is very close to the Pleiades star cluster and the Evening Star (Venus). Get out your binoculars, this will be very attractive sight.

The moon appears on the other side of the Hyades star cluster on the 29th. So it will be fairly close to Aldebaran, the brightest star of Taurus the Bull. Again, this will be a good night for your binoculars.

Mars sweeps past Saturn on the morning of the 31st. Recall that just 11 days ago, Mars was just beneath Jupiter. Now it’s Saturn’s turn to have a Martian visitor.

On the evening of the 31st, the moon is six degrees from M-35, a star cluster in the feet of Gemini the Twins. M-35 is not as flashy of the Pleiades or even the Beehive star cluster. If you have a small telescope or even spotting scope, the view is better than through binoculars. However, it’s still worthwhile looking for this star cluster with your binoculars.

References

https://en.m.wikipedia.org/wiki/March

http://astropixels.com/ephemeris/astrocal/astrocal2020gmt.html

http://www.seasky.org/astronomy/astronomy-calendar-2020.html

https://in-the-sky.org/newscalyear.php?year=2020&maxdiff=7

The Stargazing Almanac

for February 2020

February

February is the 2nd month of the modern calendar, but it didn’t exist in the old Roman calendar. Initially, the Roman year began in the spring with March. It wasn’t until 450 BC that the winter months of January and February came into existence in their calendar. Prior to that, the winter was considered a time without months. The name February comes from the Latin name for the month, Februarius. The name Februarius is derived from the Latin term for purification, februum. The reason why is that this time of the year was a time of purification and the ritual was called Februa. Initially, February was considered the final month of the year since the year originally began in March. 

February nominally has 28 days (making it the shortest month of the year), but every four years, like in 2020, February has 29 days. The reason we have leap years is that the length of the year is closer to 365.24 days. Therefore, every four years, the modern calendar falls behind by nearly a day. The once every four adjustment is not perfect, however. Therefore, we only treat centuries divisible by 400 as leap years.

On February 1st, the sun rises at 8:04 AM and sets at 5:54 PM. And on February 28th, the sun rises at 7:25 AM and sets at 6:30 PM. These times are for Boise, Idaho.

The five visible planets reside in the following constellations this month.

Mercury: Aquarius (morning planet)

Venus: Aquarius and Pisces (evening planet)

Mars: Ophiuchus and Sagittarius (morning planet)

Jupiter: Sagittarius (morning planet)

Saturn: Sagittarius (evening planet until midmonth)

Bellatrix

This month look for the star Bellatrix, the upper right star in the shoulder of Orion the Hunter. Bellatrix is the third brightest star in Orion, after Rigel and Betelgeuse. The star is 250 light years away, meaning that the Bellatrix you see tonight is actually from 1770. It’s a young star at an estimated age of 25 million years old.

Bellatrix has a mass eight times greater than the sun’s. With that additional mass squeezing down on its core, Bellatrix fused its hydrogen supply so fast that it has probably used up its original supply. As a result, the star is now fusing helium and expanded to a giant white star. The higher temperatures needed to fuse helium makes the star’s surface temperature some four times hotter than the sun’s. Burning helium means that before we know it (but not soon on a human scale), the star will most likely expand into a red giant before dying as a white dwarf.     

The word Bellatrix is Latin for Female Warrior. So it’s not surprising to hear that Bellatrix is also known as the Amazon Star. Look for the Amazon Star in the south after it gets dark on February nights.

The moon drifts past the Pleiades on the 1st and 2nd. This means the night of the 2nd is a good time to look for the moon near the two large star clusters, the Pleiades and the Hyades. Both star clusters make great binocular objects. However, you’ll find that the Pleiades are the more compact and sparkly target. The Hyades isn’t as flashy since it has dimmer and more spread out stars. They’re a nice study in contrasts for this reason.

The moon reaches first quarter on the 2nd. First quarter, or half-moon is one with a terminator or boundary between day and night facing directly towards observers on Earth. This has the effect of stretching out the shadows cast by sunrise on the moon. The long shadows accentuate elevation changes on the moon making even tiny imperfections easier to see.

This means craters and mountain peaks stand out in stronger relief at first quarter. So aim your binoculars, spotting scope, or small telescope along the moon’s terminator at first quarter. You’ll find lots of craters in the moon’s southern hemisphere and more mountains in the north.

On the 3rd, the moon is only three degrees from Aldebaran. A good chunk of the Hyades star cluster and moon are visible together through binoculars.

The brightest star cluster in Gemini the Twins is called M-35. The cluster is attractive in an amateur telescope, but not as flashy as say the Beehive star cluster. However, it is still visible through binoculars. So aim your binoculars at the moon on the 5th and place it at the 7 o’clock position. The star cluster will appear inside your view at the 1 o’clock position.

Expect to see as many as 15 stars in a region spanning the size of the moon. Larger and more powerful binoculars are preferable.

If you’re viewing from a location with some background light, then try using averted vision on this star cluster. Averted vision means not looking directly at the star cluster. That way the more light-sensitive edge of your retina is doing the looking.

The moon glides along the bottom edge of Gemini the Twins on the night of the 6th. This side represents the brother Pollux. Use this star map to identify the rest of the constellation.   

     

The nearly full moon appears within four degrees of the Beehive star cluster on the night of the 7th. The star cluster is bright and big, and therefore a perfect target for your binoculars. If you place the moon at the top right of your binoculars’ view, then the star cluster will appear just below the center of your view. For a better look, move the moon out of the sight so it’s light cannot interfere with your view. You’ll see about two dozen stars scattered across and area about the size of the moon.

The moon is full on the 9th. The full moon in February is called the Snow Moon on account of the year’s heaviest snowfalls that we can experience this month. Through binoculars or telescope, the full moon is blinding bright. But have no fear, the effect is temporary. The dark patches on the lunar surface are maria and consist of frozen seas of lava.

They date back to over 3.5 billion years ago and formed while the moon’s core was still warm from its formation and radioactive decay.  

The full moon is residing in the constellation of Leo the Lion on the 9th and 10th. To the moon’s right is Leo’s brightest star, Regulus. This star is also known as Alpha Leonis. Regulus is a multiple star system. Although you can’t see every star through your binoculars, you should be able to see the brightest companion star of Regulus through your binoculars.

Mercury is seldom seen by the public on account of its closeness to the sun. Therefore, any time this elusive planet makes one of its brief appearances is a time to take note and go outside for a moment. Such is the evening of the 11th. Look for Venus to the lower right of brilliant Venus, the Evening Star. Mercury will be the only noticeable point of light just above the western horizon. You won’t need binoculars to see Mercury, just a clear and low horizon. By the way, you have several days before and after to see Mercury. It will just be even closer to the horizon. 

      

Stargazers staying up after midnight on the 13th have a good opportunity to see the waning gibbous moon near the brightest star of Virgo the Maiden.

This star is called Spica and its 250 light years away. The rest of Virgo is very dim, but it’s a large constellation.

The moon then passes close to a wide double star on the 15th. This one is called Zubenelgenubi and it’s one of the brightest stars in Libra the Scales. Originally, it was one of the claws of Scorpius the Scorpion. Some people with exceptional eyesight can split this point of light into two separate stars. The rest of us mere mortals need to rely on our trusty pair of binoculars. Zubenelgenubi is the brightest star to the moon’s left. You’ll need to go outside a few hours before sunrise to observe this double star.

The moon is at its third quarter phase on the 15th. This is another half-moon, but one that illuminates the moon’s western hemisphere. That means it’s a great phase to go exploring through binoculars, spotting scope, or telescope.

Idahoans get to see the moon uncover Mars on the morning of the 18th. This event is called an occultation and unfortunately, we don’t get to see the moon pass over Mars. But if you aim your binoculars at the moon before 5:45 AM on the 18th, you’ll be ready for the reappearance of Mars.

Mars will reappear from the moon’s upper right at around 5:47 AM. So be ready early. Mars will gradually reappear since it has an apparent diameter greater than a star’s. After Mars reappears, look slightly further to the lower right for a fuzzy nebula. This is the Lagoon Nebula and you just might see a sprinkle of stars inside the nebula. This is a star-forming region. The gas and dust of the nebula are collapsing into a new generation of stars. And in kind, the light of those new stars make the nebula glow. 

Hey, are you looking for Jupiter? Well, it has rounded the other side of the solar system and has reappeared in the morning skies. The moon will help you locate the solar system’s largest planet on the morning of the 19th. If you go outside at around 6:30 AM, you’ll find the moon in the low southeast. Jupiter is the bright star just to the left of the waning crescent moon. Both the moon and Jupiter will be great binocular objects. In fact, you can see up to three of Jupiter’s largest moons on the 19th. From left to right, you’ll see Callisto, Jupiter, Europa, and Ganymede. Fiery Io will be too close to the left side of Jupiter to be seen through the planet’s glare. However, a small telescope will show you even Io.

  

On the next morning, the 20th, the moon passes close to Saturn. But this pairing will be more difficult to see for two reasons. First, Saturn is fainter than Jupiter and for another, the moon and Saturn appears even closer to the horizon. That means binoculars will be helpful to seeing this event. Look for the only star just above the thin crescent moon. Binoculars won’t show any detail on Saturn and not that much on the moon since it is so thin.

The moon is new and passes closest to the sun on the 23rd. The moon is invisible to the unaided eye since it doesn’t appear in the sky after sunset. Wait a couple of days and you’ll see the moon at dusk as a waxing crescent in the low southwest. 

The moon reappears in the evening sky on the 25th. It will only be two days and five hours old. So expect a thin moon with no detail visible. Still, it should be an attractive sight.

By the 27th, the moon appears significantly higher above the horizon and close to Venus. Look this bright pair in the west after it gets dark on the 27th. It should make for an attractive target for your camera.  

References

https://en.m.wikipedia.org/wiki/February

https://www.star-facts.com/bellatrix/

http://astropixels.com/ephemeris/astrocal/astrocal2020gmt.html

http://www.seasky.org/astronomy/astronomy-calendar-2020.html

https://in-the-sky.org/newscalyear.php?year=2020&maxdiff=7

https://en.m.wikipedia.org/wiki/Spica