Skywatcher's Guide: June and July 2023



Stars and Constellations

In June, the spring sky is now prominent overhead, along with the familiar Big Dipper.  The Big Dipper is high in the north, and the two stars at the end of the bowl can be used to find Polaris, our north star.  Also, the handle can be used to "arc to Arcturus", a bright star in the constellation Boötes. Then Hercules is just below towards the east.  Next, Leo the lion is very high in the west, with the constellation Virgo nearby to the south.  A few winter constellations are still visible, now very low in the west.  Castor and Pollux, the heads of Gemini the twins, are the most prominent, to the west-northwest.  The summer sky is now just starting to come up at the beginning of the night.  The bright star Vega in the constellation Lyra the harp is towards the east-northeast.  In the southeast we have the constellation Scorpius the scorpion, with the bright star Antares.  Further to the south we can also see the constellations of Centaurus and Lupus the wolf right along the horizon.

In July, the last of the winter constellations are now gone, and the spring constellations are beginning to head to the west.  The summer constellations are now mostly up in the east.  We can easily see all three stars in the Summer Triangle, Vega being the highest in the east-northeast, Deneb a little lower to the northeast, and Altair to the east.  To the southeast we can see the Teapot of Sagittarius near the tail of Scorpius.  Also, to the north-northeast we can see the W of Cassiopeia the queen.

Interesting Stars Visible in June and July (during observatory hours)

Name / Designation Apparent Magnitude
(lower = brighter)
Arcturus -0.05 36.7  
Vega 0.03 25  
Capella 0.08 42  
Procyon 0.4 11  
Altair 0.76 17  
Spica 0.98 262  
Pollux 1.16 38  
Markab 1.25 140  
Deneb 1.25 3230  
Regulus 1.36 77 means "Little King"
Castor 1.58 52  
Polaris 1.97 431  
Alpheratz or Sirrah 2.07 97  
Denebola 2.14 36.2  
Enif 2.38 670  
Albireo 3.2 / 5.8 & 5.1 390 / 380  possibly a triple star system
Eta Cassiopeiae 3.5 / 7.4 19 480 yr orbit

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Solar System

Mercury will be visible in the morning sky in early June but will be passing behind the Sun at the end of the month.  It will then re-emerge in the evening sky in late July.

Venus reaches its highest point in the evening sky in early June and will sink quickly but remain visible until the end of July.

Mars is getting lower in the evening sky, moving through Cancer and Leo.

Jupiter rises in the early morning in the constellation Aries.

Saturn rises in the late evening in the constellation Aquarius.

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Calendar of Night Sky Events

Date Event
06/03/23 Full Moon.
06/04/23 Venus at greatest eastern elongation. — Visible after sunset.
06/04/23 Appulse of Mercury and Uranus. — Separated by 2.7°.
06/10/23 Last Quarter Moon.
06/17/23 New Moon.
06/21/23 Earth at northern solstice. — Beginning of our Summer.
06/26/23 First Quarter Moon.
06/30/23 Mercury at superior conjunction. — Passing behind the Sun.
07/03/23 Full Moon.
07/06/23 Earth at aphelion. — Our farthest distance from the Sun.
07/09/23 Last Quarter Moon.
07/17/23 New Moon.
07/21/23 Pluto at opposition. — Best time to look for this dwarf planet.
07/25/23 First Quarter Moon.
07/27/23 Appulse of Mercury and Venus. — Separated by 5.1°.
07/28/23 Peak of Delta Aquariids meteor shower.

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Deep Sky

There are several open star clusters we can see this time of year. First, Coma Berenices (Bernice's Hair) is high in the west near the tail of Leo. Next, there is the Ptolemy cluster (M7) and the Butterfly (M6) in the southeast near the tail of Scorpius. Also nearby is the Wild Duck (M11) in the constellation of Scutum.

Now that the Milky Way is coming up, there are several globular clusters we can see. M3 is high in the west, in the constellation Boötes. Nearby, the famous Hercules Globular (M13) is high in the east. We also have M5 high in the south in the constellation of Serpens. Finally, for those with a clear horizon, the amazing Omega Centauri (C80) is visible low to the south.

For nebulae, we can see the Swan (M17), the Lagoon (M8), and the Trifid (M20) to the southeast in the constellation Sagittarius. The Eagle (M16) is nearby in the constellation of Serpens. The North America nebula is also in the northeast in Cygnus. For planetary nebulae, we have the Owl (M97) in Ursa Major high in the northwest. We also have the Dumbbell (M27) in the west-northwest in the constellation of Vulpecula and the Ring (M57) nearby in Lyra.

And now the galaxies: In Ursa Major to the northwest we have Bode's Galaxy (M81) and the Cigar Galaxy (M82), close enough to be seen together in a low-power telescope. Nearby in the constellation Canes Venatici we have the Whirlpool (M51), which is a pair of colliding galaxies. The Pinwheel Galaxy (M101) is also nearby near the handle of the Big Dipper. Then the Southern Pinwheel (M83) is to the southwest in the constellation Hydra. The Sombrero Galaxy (M104) is nearby in the constellation Virgo.

Interesting Deep Sky Objects to Observe during June and July (during observatory hours)

Designation Name Apparent Magnitude Apparent Size Distance
Messier 31 Andromeda Galaxy 3.4 3° x 1° 2,900,000 spiral galaxy
Messier 44 Beehive Cluster 3.7 95' 577 open cluster
Messier 3 (in Canes Venatici) 6.2 18' 34,000 globular cluster
Messier 27 Dumbbell Nebula 7.4 8' × 6' 1,250 planetary nebula
NGC 7009 Saturn Nebula 8 36" 2,400 planetary nebula
Messier 81 Bode's Galaxy 8.5 21' 12,000,000 spiral galaxy
NGC 3242 Ghost of Jupiter 8.6 25" 1,400 planetary nebula
Messier 57 Ring Nebula 8.8 1' 2,300 planetary nebula
Messier 82 Cigar Galaxy 9.5 14' 12,000,000 galaxy

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Frequently Asked Questions

What does retrograde mean, and does it affect anything?

Retrograde is a term commonly found in horoscopes, but it does have a real scientific meaning... actually two different meanings.  First, in general, everything in our solar system is spinning (rotating) and orbiting (revolving).  In most cases, this is in a counter-clockwise direction as viewed from the north, specifically the north ecliptic pole.  But a small percentage of objects either spin or orbit clockwise.  Venus, for example spins clockwise, so we say it spins retrograde.  The biggest object to orbit retrograde is Neptune's moon Triton.  Barring some catastrophic celestial event, these objects are always retrograde under this definition.

The second meaning to the term retrograde is the one astrologers are concerned with.  As viewed from Earth, most solar system objects typically appear to move from west to east in front of the background stars.  But since our motions are not linear, objects occasionally appear to switch directions and move back towards the west.  The objects aren't actually changing direction in space, but only from our point of view.  These retrograde periods can last anywhere from a few weeks to a few months depending on how close and how fast these objects are moving in their orbits relative to the Earth.

Venus, Saturn, and Neptune all begin their retrograde periods in June or July this year.  For the dwarf planets, Pluto is in retrograde the entire time, while Eris begins and Haumea and Makemake end their retrogrades in these two months.  So you can see that retrogrades in general are not uncommon.  In fact, it is very rare to have nothing in retrograde.  (If you include all the millions of asteroids, it's pretty much impossible.)

No scientific relationship has been found between planetary motion and daily events here on Earth.  For this reason astrology and horoscopes are considered pseudoscience.  When something unfortunate happens to you, it might be easy to blame such-and-such planet for being in retrograde at the time, when in fact it was merely random and could just as easily have happened when that planet was not in retrograde.

If you have any questions you'd like me to answer in the next issue of SWG, please let me know.  I'm also happy to take suggestions or comments, and also pictures if you'd like to send them.  Happy viewing!

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Date of publication: 2023