Caoimhín's Content

Today, we will be looking at the sky for late September, especially around the day of the equinox. I won’t talk about the equinox itself that much, but you can search my previous posts to find a few more focused discussions of it. I have talked about the late September sky already, however the attached video is in Irish, so I cover slightly different things to the previous posts. While we are looking at the sky during the day, it is clear to thanks to the Stellarium software that the Moon is almost in front of the Sun. The Moon is very new and very close to the Sun in the sky, but won’t be a solar eclipse for us here in Ireland. There is a solar eclipse happening, a partial solar eclipse, happening for New Zealand on these dates, on the 22nd, the day after the equinox.

Also, at this time of the year, the planet Saturn and the planet Neptune are coming to opposition. When the planet is at opposition the planet is directly behind the Earth relative to the Sun, making it appear at its brightest and closest. The planet Saturn will be at opposition on the 21st. I have covered the opposition already in a previous piece, but we’re going to zoom in on Saturn and Neptune again. We will do this at physical midnight, when they are at their highest point in the sky and most observable. When the planets that are further from the Sun than the Earth are on the same side of the Sun as the Earth, they are necessarily at their closest to us as well. Firstly, we’ll take a look at Saturn. It’s not a great year for Saturn this year as the rings are very thin here. I discussed a couple of pieces ago that in different years Saturn’s rings can have a much larger appearance. That is due to the tilt that Saturn and the Earth have in their axes. Saturn has plenty of moons, which are quite easy to see, especially Titan. If you have a telescope, Saturn is one of the best planets to look at, and the best time of the year is when they’re at opposition.

Moving onto Neptune, the planet Neptune very close to Saturn in the sky at the moment. It is a couple of days after Saturn, reaching its opposition on the 23rd. Neptune is much further from us as well, and for that reason it is a lot harder to see anything. There’s a chance that you’ll be able to see Triton, the largest moon, if you have a very big telescope, but normally you aren’t able to see anything other than a sort of blue-ish dot. It’s fairly blue, but it’s not very blue, and a couple of the stars are blue as well. It is easy enough to get mixed up if you are looking for Neptune, it often has a sort of star-like appearance in lower power telescopes.

Using a telescope to zoom in on Saturn, and a pretty big telescope at that, then we’re certainly able to see Saturn and its moons. With a 10 inch aperture telescope, with some eyepiece help, we’re able to see the rings, even though they are thin at this time of the year. If we are focusing in on Neptune, we’re not going to see the same amount of detail. We can see one of the moons and we can see that sort of blue colour. However, without the eyepieces you are only able to see the planet. With a larger telescope, one of the biggest ones that you can use in Stellarium at 16 inches aperture, Neptune and Triton are visible. If we go back to Saturn using the same telescope and the same equipment, we get a very clear view of Saturn and its rings. There’s a very big difference between the distance from the Earth to each of these planets, to the extent that we can see Saturn with out naked eye, and we can’t see Neptune with our naked eye at all. Neptune is even further from us than even Uranus.

Moving out into the countryside will let us see more, but there’s still no hint provided for Neptune, the way there is for Uranus in Stellarium. Also, there’s a couple of famous things around Uranus at the moment which can help you find it. Other than Saturn, there’s no such features around Neptune. There’s no star clusters or anything like that around it, the way that the Pleiades or the Seven Sisters are next to Uranus. Pushing ahead towards morning, we still have Venus, nice and bright in the morning, and especially if you are out in the countryside you’ll be able to see Venus late enough. We are after the equinox now, looking at the sky at 7:15 in the morning, Venus and Jupiter are visible.

That’s from the countryside, if you are free from light pollution. If you’re in the city it will be harder to see things like that and you won’t see the planets as late in the morning. Turning around the west, Mars is down at the horizon at sunset. If you are by the seaside then there’s a chance that you’ll be able to see Mars, but it will be hard for almost everyone. The ground isn’t completely smooth in the vast majority of places, usually there are hills and trees and stuff like that in the way. With a perfectly flat horizon, Mars visible down at the horizon at sunset, but due to how low in the sky it is there’s a lot of air in the way. For that reason, Mars isn’t as bright as it could be from other places in the world or at other times of year. Turning a little north of west, we can see the Plough, pointing the way to the north star, and with its handle the way to Arcturus in the constellation Boötes. I’m after talking about Boötes in another piece recently due to the Boötes Void. Bringing back a normal horizon, with and trees and hills and everything like that, Mars is just a little too low for us to see it.

If you are out in the countryside, the equinox is a good enough night for stargazing. As the nights are getting longer now, it will be easier and easier to see things during the night, and you have more time to see things, However, as we push ahead, into October and November, at the same time of the night we see less of our galaxies core. We’re losing the Milky Way’s center, it will be behind the Sun within a couple of months and even before it goes straight behind the Sun, the glow of sunset will block it out. This means, we’ll see less and less of it in the sky. Less and less of the middle in any case, the part that’s most full of stars and nebulae and other interesting things. The other parts of the Milky Way, they’ll be up for the vast majority of the winter, we’ll be able to sort of see the outer limbs of the galaxy, but they are fainter and harder to see. Also, we’re losing the summer triangle. The summer triangle won’t be up for the entire night when we’re into winter, and we are almost into winter now according to the stars. The nights are getting longer than the days, the temperature is going down and things are getting colder. We are going into winter even if we are still in autumn. The autumn in irish is An Fómhar, and September is Méan Fómhair, Mid-Autumn. Nonetheless we are going in the direction of winter, and due to that, we will have more time to look at the stars, but we will be losing the Milky Way, the most of it at least.

In the morning there are more constellations, like Orion or An Bodach, Taurus the Bull, and the brightest star Sirius in the constellation Canis Major, the Big Dog, all up a bit after midnight. Those famous constellations will be coming back into the sky at night, and for that reason easier to see, as we push later in the year. We will be losing other constellations, like Sagittarius and Scorpius. If we turn around to the north, the Plough is there all night of course, and at this time of the year it goes low for us when we are coming past midnight, under the North Star. Looking at 1:15 the Plough is almost right under the North Star, and due to the Summer Time that we are still using, that is midnight. I’m after taking about daylight savings time and time zones, and how things are seen in the sky at different times but the same physical time. I’m after talking about that already in previous pieces, so again you can search the older posts to learn more. The stars that are visible up in the north, they’ll be visible for the whole winter and indeed the whole year, they aren’t going to change. It is in the other side of the sky in the south that changes are going to happen.

Very quickly, as it is important and interesting, we’re going to head to New Zealand, the southern tip of the South Island of New Zealand for an eclipse. Looking at the Sun and the Moon, we should be able to see a partial solar eclipse on the 22nd. Just as the Sun is rising in the east, the Moon will go in front of the Sun. It is a partial eclipse, this location gets close enough to the greatest amount of the eclipse that anyone will be able to see, up to 70%. You can’t see it if you aren’t down in New Zealand, along with small parts of Australia and Oceania. Also from some parts of Antarctica as well if you are down in Antarctica.

Those are the important things, the equinox, the solar eclipse and the planets Saturn and Neptune coming to opposition, those are the important things that are coming up at the end of this month. If you have the chance to go look at these events then good luck, I’m sure that you’ll be able to look at these things if the weather is good enough and if you’re in the right place. If you enjoyed this piece then please do like it and if you enjoy this kind of content then make sure you subscribe to this website and my YouTube channel. Thank you very much for reading, and I’ll see you back here next time.