Here is a listing of upcoming events and activities that the Hamilton Chapter of the RASC will be conducting. If you are interested in Astronomy, come check us out or contact us for more details!
Monthly Night Sky information provided by Chris Vaughan (@Astrogeoguy) at Starry Night Education (@StarryNightEdu).
September 2024
Sunday, September 8 – Mars Clips a Cluster (wee hours) On the way to Mars’ bright opposition in January, the red planet will slide closely past several planets and deep sky objects. On Sunday night, September 8, Mars will pass less than a finger’s width to the lower right (or 0.9 degrees to the celestial south) of the large open star cluster in Gemini named the Shoe-Buckle, Messier 35, and NGC 2168. The planet and the distant cluster will share the field of view in a backyard telescope from Friday to Wednesday, and in binoculars for a week on either side of September 8. Mars will approach the cluster from the right (celestial west), but your telescope will likely flip and/or mirror the view.
Monday, September 9 – Mercury Raids Regulus (before sunrise) Skywatchers with a clear view to the east before sunrise on Monday morning, September 9 can use binoculars or a backyard telescope to see the speedy planet Mercury shining very close to the 7 times fainter, white star Regulus. Mercury’s daily descent towards the sun will cause it to approach Regulus from above on the prior mornings and then drop out of sight about a week later. On Monday, Mercury will appear just half a degree to Regulus’ left (or celestial north). In a telescope Mercury will display a waxing gibbous phase.
Monday, September 9 – Moon Dances with the Scorpion (early evening) Once the sky has darkened on Monday evening, September 9, the stars of Scorpius will appear to the left (or celestial east) of the waxing crescent moon. The bright, reddish star Antares, which marks the heart of the scorpion, will shine a palm’s width to the moon’s left. The up-down row of fainter stars that form the claws of the critter will extend upwards through the moon. Observers located in eastern Canada and the northeastern USA can see the moon occult the magnitude 2.85 claw star Pi Scorpii. Hours later, on Tuesday evening, observers in a zone west of central Australia and southeastern Indonesia can watch the moon occult Antares. An app like Starry Night can provide the occultation circumstances where you live. On Tuesday evening, the moon will hop east to shine to Antares’ left.
Tuesday, September 10 – Ptolemaeus, Alphonsus and Arzachel (evening) On Tuesday night, September 10, the terminator boundary on the waxing gibbous moon will fall just to the west of a trio of large craters located a short distance south of the moon’s center. Ptolemaeus, Alphonsus, and Arzachel are all large enough to see with binoculars and any size of telescope. The northernmost crater Ptolemaeus (96 miles or 154 km wide) has been battered by later impacts that confirm its older age. The flat, almost featureless floor has been filled by lava flows, submerging its central peak and elevating its floor. Alphonsus (74 miles or 119 km wide) is older yet, and only partially filled, allowing its central peak to remain visible. Alphonsus contains a triangle of dark spots that are most prominent when the moon is full – ash deposits from long-ago volcanic venting. Relatively young Arzachel (60 miles or 96 km wide) has an unaltered floor and a terraced rim. Numerous north-south lineations carved by ejecta blasted out during the powerful Imbrium Basin impact event surround those craters.
Wednesday, September 11 – First Quarter Moon (at 06:06 GMT) When the moon completes the first quarter of its journey around Earth on Wednesday, September 11 at 2:06 a.m. EDT or 06:06 GMT, its 90 degree angle away from the sun will cause us to see the moon half-illuminated – on its eastern side. At first quarter, the moon always rises around mid-day and sets around midnight, so it is also visible in the afternoon daytime sky, too. The evenings surrounding first quarter are the best ones for seeing the lunar terrain when it is dramatically lit by low-angled sunlight, especially along the terminator, the pole-to-pole boundary that separates the lit and dark hemispheres.
Friday, September 13 – Major Mare Imbrium (evening) On Friday, September 13, the lunar terminator will fall just beyond the western rim of Mare Imbrium, the Sea of Rains, allowing it to be fully illuminated. That dark, circular feature dominates the northwestern quadrant of the moon’s Earth-facing hemisphere. The mare is the moon’s largest impact basin, measuring more than 715 miles (1,145 km) in diameter. It was formed during the late heavy bombardment period approximately 3.94 billion years ago. Telescope views of Mare Imbrium at this phase will reveal ejecta blankets around its major craters (Aristillus and Archimedes), several nearly-submerged ghost craters (Cassini and Wallace), and numerous subtle wrinkle ridges (Heim, Stille).
Friday Sep 13 – Friday Night Sights at the Observatory
Saturday, September 14 – The Aristarchus Plateau (all night) Three prominent craters break up the expanse of Oceanus Procellarum, the widespread dark region on the moon’s left-hand side. Large Copernicus is the easternmost of the craters. Its extensive, ragged ray system intermingles with that of the smaller crater Kepler to its southwest. The very bright crater Aristarchus positioned northwest of them occupies the southeastern corner of a diamond-shaped plateau that is one of the most colorful regions on the moon. NASA orbiters have detected high levels of radioactive radon there. Use a telescope and high magnification to view features like the large, sinuous rille named Vallis Schröteri. Its snake-like form begins between Aristarchus and next-door Herodotus and meanders across the plateau.
Monday, September 16 – Bright Moon Shines with Saturn (all night) After the bright, waxing gibbous moon clears the eastern rooftops in early evening on Monday, September 16, the yellowish dot of Saturn will shine prominently to its left (or celestial northeast). As the pair cross the sky overnight, the moon’s eastward orbital motion will carry it closer to Saturn. Meanwhile, the diurnal rotation of the sky will lift Saturn above the moon by the time they set in the west before dawn. Observers on the west coast of North America and within a zone extending south and west to northern Australia, Melanesia, southern and eastern Micronesia, and northwestern Polynesia (including Hawaii) can watch the moon occult Saturn. Use an app like Starry Night to look up the occultation timings for your location.
Tuesday, September 17 – Full Harvest Supermoon (at 10:34 PM EDT) The moon will officially reach its full phase on Tuesday, September 17 at 10:34 p.m. EDT or 7:34 p.m. PDT, which converts to 02:34 GMT on Wednesday. With perigee arriving only 10 hours later, this full moon will also be the second of four supermoons in 2024. It will appear about 6% larger and 16% brighter than an average full moon cross the sky from sunset to sunrise, and will produce large tides around the world. The September full moon, traditionally known as the “Corn Moon” and “Barley Moon”, always shines in or near the stars of Aquarius and Pisces. The indigenous Anishinaabe people of the Great Lakes region call this moon Waatebagaa-giizis or Waabaagbagaa-giizis, the Leaves Turning or Leaves Falling Moon. Because this is the closest full moon to the autumnal equinox in 2024, it is also the Harvest Moon. On the evenings around its full phase, the moon normally rises about 50 minutes later than the previous night. But the shallow slope of the evening ecliptic (and the moon’s orbit) around the equinox causes Harvest Moons to rise at almost the same time each night – only delayed by as little as 10 minutes, depending on your latitude. This phenomenon traditionally allowed farmers to work into the evening under bright moonlight – hence the name.
Tuesday, September 17 – Partially Eclipsed Harvest SuperMoon (at 10:34 PM EDT) The northerly portion of this full moon will also dip into Earth’s umbra for 63.7 minutes, generating a shallow partial lunar eclipse visible across the Americas (except Alaska), the Atlantic Ocean, and western Europe and Africa. The moon will begin to enter Earth’s penumbra, slightly darkening it, at 8:41 p.m. EDT. A small “bite” out of the moon will be visible between 10:13 p.m. and 11:16 p.m. EDT, with a maximum of 8.5% of the moon within Earth’s shadow at 10:45 p.m. EDT. The moon will fully emerge from Earth’s penumbra at 12:48 a.m. EDT. Lunar eclipses are completely safe to look at without protective filters.
Wednesday, September 18 – Bright Lunar Ray Systems (all night) While the moon is near its full phase, bright ray features may be seen radiating from the younger craters on the lunar near side. The impact that created the bright crater Tycho, which is located in the south-central area of the moon, produced streaks of bright material that extend in multiple directions across the moon’s near side. Another particularly interesting ray system surrounds the crater Proclus. The 16 mile (27 km) wide crater and its ray system are visible in binoculars. They are located at the lower left edge of Mare Crisium, the round grey basin near the moon’s upper right edge (northeast on the moon). The Proclus rays, about 370 miles (600 km) in length, only appear on the eastern, right-hand side of the crater, and within Mare Crisium, suggesting that the impactor arrived at a shallow angle from the southwest. The small crater Menelaus on the southern edge of Mare Serenitatis hosts some small rays. A long, possibly unrelated, ray passes through both Menelaus and the mare.
Friday, September 20 – Neptune at Opposition (all night) On Friday night, September 20, Neptune will reach opposition. At that time the distant planet will be closest to Earth for this year – a distance of “merely” 2.68 billion miles, 4.32 billion km, 4 light-hours, or 28.9 Astronomical Units. At opposition, blue Neptune will shine with a slightly enhanced magnitude of 7.8. Since it will be opposite the sun in the sky, Neptune will be visible all night long in backyard telescopes. Good binoculars can show it, too, if your sky is very dark – but unfortunately, Neptune will have to share the sky with a very bright moon. Your best views will come after 9 p.m. local time, when the blue planet has risen higher. Around opposition, Neptune’s apparent disk size will peak at 2.4 arc-seconds and its large moon Triton will be the most visible (inset). Throughout September, Neptune will be located below (or celestial southeast of) the circle of stars that forms Pisces’ western fish, and about a thumb’s width above the medium-bright star pair 29 and 27 Piscium. Much brighter Saturn will shine 1.3 fist diameters to the upper right (or 13.5 degrees to the celestial west-southwest) of Neptune.
Friday Sep 20 – Friday Night Sights at the Observatory
Saturday, September 21 – Bright Moon Kisses the Seven Sisters (overnight) When the still very full and bright, waning gibbous moon rises over the rooftops to the east on Saturday evening, September 21, the bright little cluster known as the Pleiades, the Seven Sisters, the Hole in the Sky, Matariki, and Messier 45 will be sparkling several finger widths to the moon’s lower left – close enough for them to share the view in binoculars. To better see the stars, which are spread over an area nearly four times larger than the moon, hide the moon beyond the upper right edge of your binoculars’ field of view. Skywatchers viewing the scene later at night, and in more westerly time zones, will see the moon approach closer to the cluster, pass among its stars around 11:00 GMT, and then begin to move off to their east. The faint blue speck of Uranus will also be positioned less than a palm’s width to the right (or 5 degrees to the celestial SSW) of the Pleiades.
Sunday, September 22 – September Equinox (at 12:44 GMT) On Sunday, September 22 at 8:44 a.m. EDT, 5:44 a.m. PDT, or 12:44 GMT, the sun’s apparent motion along the ecliptic will carry it across the celestial equator traveling southward, marking the autumnal equinox in the Northern Hemisphere and the beginning of autumn there. On the equinoxes in March and September, day and night are of equal length and the sun rises due east and sets due west (yellow arc).
Monday, September 23 – The Moon Visits Jupiter in the Winter Hexagon (wee hours to dawn) Late on Monday evening, September 23, the gorgeous half-moon will rise in the east with brilliant Jupiter shining a palm’s width to its right (or 6 degrees to its celestial southwest). The prominent star Elnath, which marks the northern horn tip of Taurus, the Bull, will sparkle just above the moon. The trio will climb high into the southern sky by dawn. If you head outside before the sky brightens, watch for the bright ring of the Winter Hexagon asterism’s stars surrounding Jupiter and the moon. Jupiter will spend the coming year wandering inside the hexagon. The moon will visit it monthly.
Tuesday, September 24 – Third Quarter Moon (at 18:50 GMT) The moon will complete three quarters of its orbit around Earth, measured from the previous new moon, on Tuesday, September 24 at 2:50 p.m. EDT and 11:50 a.m. PDT or 18:50 GMT. At the third (or last) quarter phase the moon appears half-illuminated, on its western, sunward side. It will rise around midnight local time, and then remain visible until it sets in the western daytime sky in early afternoon. Third quarter moons are positioned ahead of the Earth in our trip around the Sun. About 3½ hours later, Earth will occupy that same location in space. The week of dark, moonless evening skies that follow this phase are the best ones for observing fainter deep sky targets.
Wednesday, September 25 – Crescent Moon Meets Mars (wee hours to dawn) Once the waning crescent moon has cleared the eastern treetops shortly after midnight on Wednesday morning, September 25, look for the prominent ochre dot of Mars shining less than a palm’s width below it (or about 5 degrees to the celestial south). The pair will be close enough to share the view in binoculars, and will make a nice widefield photo when framed with bright Jupiter and the bright winter stars off to their upper right.
Thursday, September 26 – Waning Moon passes Gemini’s Twins (pre-dawn) Early risers on Thursday morning, September 26, can see the pretty sight of the waning crescent moon shining below Gemini’s brightest stars Pollux and Castor. The moon will be close enough to the lower star, warm-tinted Pollux, for them to share the field of view of binoculars and backyard telescopes. Reddish Mars will be shining to the moon’s upper right. With each passing hour, the moon will shift noticeably right to left (or eastward) below Pollux.
Friday, September 27 – The Great Square of Pegasus (all night) Pegasus, which is climbing the Eastern sky during evening in September, contains one of the most recognizeable asterisms in the sky, a giant square of four similarly bright stars called the Great Square. The square’s edges are about 1.6 fist diameters (or 16°) in length, and it spans two fist widths (about 20°) measured corner to corner. The pattern might remind you of a baseball diamond when you see it, because it’s often tilted with one corner downwards. For the Lakota people, the square represented the great shell of Keya, the Turtle. The Anishinaabe of the Great Lakes region view the square as the torso of Mooz, the Moose. Using unaided eyes only, from the suburbs, the Great Square appears empty. Look carefully for two dim stars offset to the upper right from the centre of the square. They represent the moose’s heart.
Friday Sep 27 – Friday Night Sights at the Observatory
Saturday, September 28 – The First Known Exoplanet (all night) In the eastern sky on starry September evenings, look for a dim star shining a thumb’s width just outside of the baseball diamond shape of Pegasus’ Great Square, midway between the top and right corners. That yellow, sunlike star named Helvetios (or 51 Pegasi) is orbited by the first exoplanet ever discovered, in 1995. The planet, which orbits that star every 4.23 days at a distance much closer to the star than Mercury does in our solar system, is categorized as a Hot Jupiter type. Originally nick-named Bellerophon, one of the original riders of Pegasus in Greek mythology, the planet is now officially named Dimidium, the Latin word for “half” – since the planet has half the mass of Jupiter.
October 2024
Friday Oct 4 – Friday Night Sights at the Observatory
Friday Oct 11 – Friday Night Sights at the Observatory
