Skywatcher's Guide: October and November 2019
- Stars and Constellations
- Solar System
- Calendar of Night Sky Events
- Deep Sky
- Frequently Asked Questions
Stars and Constellations
In October, only a small portion of the spring sky is still visible at the beginning of the night. The Big Dipper (Ursa Major) is low in the north-northwest. As always, the last two stars in the bowl point to Polaris, our north star, in the Little Dipper (Ursa Minor). You can also still follow the arc of the handle of the Big Dipper to Arcturus, the bright star in Boötes, now low in the west-northwest. The summer constellations are also visible for a good portion of the night, starting the night in the middle of the sky. The Summer Triangle is almost directly overhead, with Vega closest to the west-northwest, Deneb closest to the northeast, and Altair closest to the south. The summer Milky Way is still prominently streaking across the sky, cutting from the northeast to the southwest. Scorpius with the bright star Antares is now getting low in the southwest, and the nearby "teapot" of Sagittarius in the south-southwest. The fall sky is now very prominent, taking up most of the eastern sky at the beginning of the night. The "W" of Cassiopeia is easy to spot in the northeast, with Perseus just below. The Great Square of Pegasus is up in the east, and Andromeda nearby in the east-northeast. There is also a fairly bright star called Fomalhaut in the southeast, though its constellation Piscis Austrinus is not easy to distinguish.
In November, all but a few of the spring stars are now gone, and the summer constellations are starting to get lower in the west. Deneb is the highest point of the Summer Triangle, with Vega below to the west, and Altair towards the southwest. The brightest part of the summer Milky Way is now gone, but a good portion of it is still easy to distinguish. Scorpius is now gone, but the "teapot" of Sagittarius is still above the horizon in the southwest. The fall sky is now a little higher, but still in the eastern half of the sky. We can now begin to see a few winter stars coming up along the eastern horizon, namely the bright Capella in the northeast and Aldebaran in the east-northeast. Also look for the Pleiades (aka the Seven Sisters or Subaru) star cluster just above Aldebaran.
Interesting Stars Visible in October and November (during observatory hours)
|Name / Designation||Apparent Magnitude
(lower = brighter)
|Alpheratz or Sirrah||2.07||97|
|Almak||2.1 / 5.0 & 6.3||355||triple star system w/ 64 yr orbit|
|Albireo||3.2 / 5.8 & 5.1||390 / 380||possibly a triple star system|
|Eta Cassiopeiae||3.5 / 7.4||19||480 yr orbit|
Mercury will be visible in the evening sky for most of October. It will pass directly in front of the Sun on Nov 11, and then will be visible in the morning sky by the end of the month.
Venus is now visible in the evening sky after sunset, slowly getting higher and higher each night.
Mars is becoming visible in the morning sky before sunrise, gradually rising earlier and earlier.
Jupiter is visible in the southwest after sunset, moving through Ophiuchus and into Sagittarius.
Saturn remains visible in the evening sky just above the teapot in Sagittarius.
Note: The GRS is visible on the disk of Jupiter for 50 minutes before and after meridian transit time.
|Date||Meridian Transit Time|
|10/05/19||First Quarter Moon.|
|10/08/19||Peak of Draconids meteor shower.|
|10/19/19||Mercury at greatest eastern elongation. — Visible in the evening after sunset.|
|10/21/19||Last Quarter Moon.|
|10/22/19||Peak of Orionids meteor shower.|
|10/28/19||Uranus at opposition. — Best time to see this gas giant.|
|10/30/19||Appulse of Mercury and Venus. — Separated by 2.5°.|
|11/04/19||First Quarter Moon.|
|11/11/19||Mercury at interior conjunction. — Rare transit as it passes directly in front of the Sun.|
|11/17/19||Peak of Leonids meteor shower.|
|11/19/19||Last Quarter Moon.|
|11/24/19||Appulse of Venus and Jupiter. — Separated by 1.4°.|
|11/24/19||Appulse of Mercury and Mars. — Separated by 9.5°.|
|11/28/19||Mercury at greatest western elongation. — Visible in the morning before sunrise.|
There are many deep sky objects we can see since the summer Milky Way is high in the sky. There are many open star clusters that can be seen with only binoculars scanning this part of the sky. For example we have the Butterfly Cluster (M6) and Ptolemy's Cluster (M7) near the tail of Scorpius. Further north there is the Wild Duck Cluster (M11) in the faint constellation of Scutum between Sagittarius and Aquila. There is also the asterism of the Coathanger between Aquila and Cygnus in the fainter constellation of Vulpecula. Next, heading towards the west we can see the Coma Star Cluster in the constellation of Coma Berenices, which is even visible naked-eye. The Pleiades (M45) will be visible later in the night, after midnight.
There are a several globular clusters we can see as well, as the center of our galaxy is the highest it gets for the year. Near the bright star Antares in Scorpius lies the globular cluster M4. In Sagittarius we also have the Teapot Cluster (M22). Of course we have the famous Hercules globular (M13) high in the east. Also, M15 is visible in the east near the head of Pegasus.
For nebulae, we have several in the plane of the galaxy, one of which is the Swan Nebula (M17) in Sagittarius, also known as the Omega Nebula. There is also the Lagoon Nebula (M8) nearby and the North America Nebula (C20) further north in Cygnus. For planetary nebulae we have the Ring Nebula (M57) in Lyra, the Dumbell Nebula (M27) in Vulpecula, and the Blue Snowball (C22) in Andromeda.
And now the galaxies: Although the Big Dipper is getting lower in the sky, you may still be able to find some of the galaxies in this part of the sky. We have the Whirlpool Galaxy (M51) and the Pinwheel Galaxy (M101) near the handle, and the Cigar Galaxy (M82) and Bode's Galaxy (M81) near the bowl. The spectacular Andromeda Galaxy (M31) is now coming up in the northeast, along with the nearby Triangulum Galaxy (M33).
Interesting Deep Sky Objects to Observe during October and November (during observatory hours)
|Designation||Name||Apparent Magnitude||Apparent Size||Distance
|Messier 45||Pleiades||1.6||110'||440||open cluster|
|Messier 31||Andromeda Galaxy||3.4||3° x 1°||2,900,000||spiral galaxy|
|Messier 42||Orion Nebula||4||85' x 60'||1400-1600||diffuse nebula|
|Messier 33||Triangulum Galaxy||5.7||67' x 42'||3,000,000||spiral galaxy|
|NGC 7293||Helix Nebula||7.3||16'||450||planetary nebula|
|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'||1,200,000||spiral galaxy|
|Messier 57||Ring Nebula||8.8||1'||2,300||planetary nebula|
|Messier 82||Cigar Galaxy||9.5||14'||1,200,000||galaxy|
Have we found Earth's twin?
While our exoplanet hunting is getting more sophisticated and we now have over 4000 confirmed discoveries, we still haven't found any like the Earth. This doesn't mean that Earth-like exoplanets don't exist, but rather that our technology is not yet to the point where we can make that kind of discovery. Of the exoplanets with determined values, about 76% have orbits that are more elliptical than the Earth's, 87% orbit their star in less time than the Earth orbits the Sun, 94% have radius bigger than Earth's, and 99% are more massive than the Earth. These numbers reveal what's called sampling bias, meaning that these types of exoplanets are the easiest/likeliest ones to discover.
You may have heard in the news recently about the discovery of water in the atmosphere of an exoplanet known as K2-18b. This is significant because this is the first such discovery on a planet in its star's habitable zone. However, that doesn't mean the planet is like Earth. For example, its radius is 2.7 times that of Earth, and its mass is 9 times. This means it would most likely be a super-earth type of exoplanet. It orbits its star in 33 days, at only about 14% the distance that Earth orbits the Sun. At such a small distance it is likely that the planet is tidally locked to its star, meaning that half of the planet is in continual daylight and half is in continual darkness. Its star is a red dwarf with only about 2% the luminosity of our Sun. While we have found water in the atmosphere, we don't know how much. It may just be trace amounts, or it may be a thick fog covering the planet. And we don't know if there is liquid water on the surface or even if the surface is the right temperature for that. In short, just because there is water doesn't mean it's Earth-like or even habitable.
So while we have found a few exoplanets with something in common with the Earth, we are still a long way off from finding one with everything in common. But stay tuned! As our technology improves, we may start finding more Earth-like planets within the next few years, slowly inching towards that goal.
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!
- Cornelius, Geoffrey. The Starlore Handbook: an Essential Guide to the Night Sky. San Francisco, CA: Chronicle, 1997. Print.
- Ottewell, Guy. Astronomical Calendar 2012. Raynham, Mass: Universal Workshop, 2011. Print.
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- Astronomy Magazine. February 2013. Volume 41, No 2.
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- Sky & Telescope. March 2013. Volume 125, No 3.