Embedded Files
Image Credit: Astronomy.com
Stargazing with Torbay Astronomical Society
September sees the start of the new season of meetings of the Torbay Astronomical Society at the Torquay Boys Grammar School. This season we begin our 70th Anniversary programme with a welcome return visit from Mr Gary Poyner FRAS, AAVSO, who will talk about “The Monster in the Crab”. In order to celebrate its 70th Anniversary the society has lined up an impressive season of speakers, many of whom are leaders in their field.
As for observing evenings, the darker skies will make fainter, interesting objects such as nebulae, star clusters and galaxies more easily visible, and the potential nova, T Corona Borealis, is still, yet to explode into view.
3I/ATLAS
There has been a lot of internet chatter (mostly nonsense) about the object designated 3I/Atlas by NASA recently. This object has entered our Solar System from Interstellar space. In other words, it did not begin its journey as part of the Sun’s family.
3I/ATLAS is not even the first object to transgress our neighbourhood. 1I/Oumuamua was a rather unusual, elongated asteroid that was discovered in 2017. One of our speakers this season was on the research team that studied this object. 2I/Borisov was a comet that originated from beyond the Oort Cloud, the reservoir of Solar System comets that lies at about 1 Light Year from the Sun. 3I/ATLAS is also a comet although it displays an unusual profile. In each of these cases the capital “I” stands for “Interstellar” in the nomenclature used.
It has been claimed that 3I/ATLAS is not a comet because it shows no sign of a coma (cloud of fuzzy material) surrounding it nor any sign of developing a tail. However, in every image I have seen the object IS surrounded by a fuzzy halo (perhaps it is just that the UFO people are used to working with poor quality, out of focus or overexposed images). The fact that no tail has been detected could be because it is not yet close enough to the Sun for the surface to melt and release the gases that usually form a tail. Furthermore the comet is currently heading straight towards the Earth although, by the time it reaches its closest point to Earth’s orbit, our planet will be safely tucked away on the opposite side of the Sun. So our current view of the comet is head-on and we cannot see the tail behind it, if it is there. Such a situation was widely observed, including by myself, during the apparition of 17P/Holmes in 2007
More recent claims have suggested an unexpected brightening to be “like headlights or the firing up of nuclear motors”. On further reading I discovered that these effects were seen on the side of the object facing the Sun – exactly where one would expect changes to occur as the object got closer to the Sun and experienced the effect of the Solar radiation. Darker surface materials would melt away revealing the pristine undersurface of the object which could be many times brighter than the rest of the object.
Sky Notes
Please note all times given in this article are in BST so remember to add an hour to get the time in BST which started on Sunday 30th March.
Sky Schedule
Please note all times given in this article are in GMT so remember to add an hour to get the time in BST which started on Sunday 30th March.
Sun: From the beginning to the end of the month the period of dark sky increases from 6.5 to 8.5 hours. The Autumnal Equinox, when night and day are of equal length, occurs on 22nd. The longer period of darkness provides a good opportunity to view the summer constellations and the Milky Way that runs through them. The Milky Way is actually our view through the spiral arms of our Galaxy which we see as a faint band of light caused by millions of distant stars.
Mercury: Mercury is too close to the Sun to be visible this month.
Venus: Venus rises about 4am and is seen as the “Morning Star” in Cancer at the beginning of the month but moves to Leo by the end of September.
Mars: Mars is too close to the Sun to be visible this month.
Jupiter: The largest planet rises half an hour after midnight and can be seen in the background constellation of Gemini. The coloured bands and zones on the surface of the planet can be distinguished with small telescopes as can the Great Red Spot, a colossal hurricane, greater in diameter than the planet Earth. The Galilean moons can be seen with a good pair of binoculars or a small (bird-spotting) telescope. DSLR images of the planet will also pick up the moons.
Saturn: The ringed planet can be seen against the background stars of Pisces all night long, although it remains low in the sky. Saturn reaches opposition (closest point to the Earth and opposite the Sun in the sky) on 21st. The rings are now beginning to open out from our point of view and are becoming increasingly spectacular to see. Saturn’s largest moon, Titan, can usually also be seen.
Uranus and Neptune: Uranus rises at about 21.30 and is seen against the constellation of Taurus, close to the Pleiades star cluster. Neptune reaches opposition (due South in the sky and at its highest elevation) on 23rd although, because of its more elliptical orbit, is closer to the Earth the day before.. At magnitude 7.7 it will require large binoculars or a small telescope to find it. Neptune displays a smaller and truly blue disc compared to that of Uranus although it will appear only as a bluish star to most small instruments.
Meteor Shower: There are no bright meteor showers due in September
Comet: There are no bright comets expected this month.
Moon: The Full Moon occurs on September 7th when the Moon will rise totally eclipsed just before 8pm. The rising Moon will appear reddish in colour due to the wavelengths of light refracted through our atmosphere. This spectacle is commonly, though mistakenly, referred to as a “Blood Moon”. The calendrical “Blood Moon” is the name usually given to the Full Moon in October that marked, to early farmers, the time to slaughter and preserve (by smoking) pigs in order to lay in meat for the winter. Third Quarter then occurs on 14th. New Moon follows on 22nd September and First Quarter on 30th.
Google Sites
Report abuse