This page provides some astronomical information on a monthly basis for those of you living in the Taunton area. Timings are in BST (British Summer Time) unless otherwise noted. Latest additions or updates are highlighted with a red border.
This month we have sections on:
Clocks in the United Kingdom and the rest of the European Union go back one hour on the last Sunday of October under the provisions of Directive 2000/84/EC of the European Parliament and of the Council. Consequently, on October 29th at 02:00 BST (British Summer Time) clocks are moved back to 01:00 GMT (Greenwich Mean Time). Any event listed here taking place after 01:00 GMT on October 29th will be given in terms of Greenwich Mean Time.
Additional information on the phases of the Moon, the seasons, summer times, eclipses, chronological cycles and eras, religious calendars, the civil calendar and holiday dates in the United Kingdom can be found in HMNAO's Astronomical and Calendarial Sheet No. 104 for 2017. This is a pdf document for which a document reader can be downloaded by clicking on the Adobe Reader icon on the right.
This web page can also be accessed from outside the UK Hydrographic Office on http://astro.ukho.gov.uk/nao/taunton.html.
An animated view of the Sun's disk over the last twenty eight days is shown in the image on the left. North is at the top of the image and east is to the left. These images come from the Helioseismic and Magnetic Imager instrument on the NASA Solar Dynamics Observatory (SDO) satellite. More multi-wavelength data from the SDO can be found here.
The Earth-facing hemisphere of the Sun's disk is spotless for the third day in a row after the disappearance of the tiny, short-lived sunspot AR2684. The Sun has now been blank for sixty six days during 2017 or 23% of the year. There is a small coronal hole in the south-western quadrant of the Sun close to the central meridian. Solar winds emanating from this feature are likely to reach the Earth on October 21st. The solar winds from the previous polar coronal hole were less vigorous than expected hence the possibility of minor G1-class geomagnetic storm activity on October 19th has diminished. A co-rotating interaction region (CIR) is expected to hit the Earth's magnetic field on October 21st bringing an increased chance of geomagnetic storm activity. This CIR is a transition region between fast- and slow-moving solar-wind streams. The density gradients and shock waves in this type of feature are a breeding ground for auroral activity. Overall solar activity remains at very low levels.
NASA reported that a reversal of the Sun's magnetic field took place at the start of 2014 indicating that the maximum of solar cycle 24 had been reached. A plot of sunspot numbers, both observed and predicted versus time indicates that this solar maximum is more complex than had been previously predicted. The maximum is double-peaked in a similar manner to that of the previous maximum of 2001/2002. The individual peaks occurred in 2011 and 2014 with the latter being the larger of the two. However, sunspot numbers are significantly down on the predictions made for this maximum — indeed solar cycle 24 may be the weakest in the last 100 years or so i.e. since solar cycle 14. Assuming the start of 2014 was the beginning of the post maximum phase of solar cycle 24, we are now well into the decreasing phase of activity where individual energetic events can spawn some of the most powerful flares and coronal mass ejections of the cycle. The so-called Carrington event of 1859 is a good example of just what might be expected from this type of violent outburst. The next solar minimum, characterized by periods of many days without sunspots and flare activity, may occur in 2019 or 2020. It is likely to be a deep minimum with long periods without much sunspot or flare activity.
The sequence of Moon phases for this month and their designations are shown in the following animation:
Moon phases specific to October 2017 are as follows:
Full Moon – Thursday October 5th at 19:40 BST
Last Quarter – Thursday October 12th at 13:25 BST
New Moon – Thursday October 19th at 20:12 BST
First Quarter – Friday October 27th at 23:22 BST
The Moon is at perigee (closest to the Earth) on Monday October 9th at 06:55 BST when it is 366,855km from the Earth. It is at apogee (furthest from the Earth) on Wednesday October 25th at 03:26 BST when it is 405,154km from the Earth.
On Monday October 9th, the Moon continues its current series of occultations of Aldebaran, the orange first-magnitude star in the constellation of Taurus. This occultation is visible from central and north-eastern Asia, northern Japan, Alaska and north-western Canada. This occultation is not visible from the United Kingdom.
On Sunday October 15th, the Moon occults Regulus, the bluish-white first-magnitude star in the constellation of Leo. This occultation is visible from the North America except most of Canada, most of the Caribbean region, Cape Verde, the Canary islands and west Africa. This occultation is not visible from the United Kingdom.
Please follow the New Moon link above to take part in our Crescent Moon Watch program which involves sighting the new crescent moon as early as possible after the instant of New Moon.
If you want to know what the Moon looks like now, try this USNO page generated by our colleagues in the Astronomical Applications Department at the US Naval Observatory in Washington.
There are four eclipses in 2017, the first of which occurred in February as a deep penumbral eclipse of the Moon which was visible in its entirety from the United Kingdom. The second eclipse of February, an annular eclipse of the Sun, was not visible from our shores. We had a very brief glimpse of the final penumbral stages of a partial eclipse of the Moon at moonrise early in August. The last eclipse of the year was a total eclipse of the Sun visible principally from the United States. It is interesting to note that as many as 250 to 300 million people were within a day's drive of the path of totality of this eclipse. It must rival the popularity of the August 11th 1999 total eclipse of the Sun seen over Europe, south-western Asia and India.
A penumbral eclipse of the Moon occurred on Friday February 10th-Saturday February 11th 2017 which was visible from western Asia, Africa, Europe, Greenland, the Americas and parts of the Pacific Ocean. This deep penumbral eclipse was visible from the United Kingdom starting at 22:32 GMT on February 10th and ending at 02:55 GMT on February 11th. Penumbral eclipses of the Moon involve very subtle changes in brightness and can be difficult to observe. From Taunton, the whole eclipse was visible.
An annular eclipse of the Sun occurred on Sunday February 26th 2017 which was visible as a partial eclipse from the south-eastern Pacific Ocean, the southern half of South America, the south Atlantic Ocean, most of Antarctica and Africa except the northern part. The path of annularity started 1800km south of Easter Island and crossed southern parts of Chile and Argentina, the Atlantic Ocean, central Angola, the north-western tip of Zambia and ended over the southern part of the Democratic Republic of Congo, 100km north west of Lubumbashi. The minimum duration of annularity was 0m44s over the mid-south Atlantic Ocean. The eclipse was not visible from the United Kingdom.
A partial eclipse of the Moon occurred on Monday August 7th 2017 which was visible from the western Pacific Ocean, Oceania, Australasia, Asia, Africa, Europe and the easternmost tip of South America. This shallow partial eclipse was visible from the United Kingdom during its final penumbral stage from 20:19 BST to 21:53 BST. From Taunton, the eclipse was visible as a penumbral eclipse from moonrise at 20:40 BST to the end of the penumbral stage at 21:53 BST.
A total eclipse of the Sun occurred on Monday August 21st 2017 which was visible as a partial eclipse from the Hawaiian Islands, the north-eastern Pacific Ocean, Oceania, North and Central America, northern parts of South America, the westernmost tip of Europe and West Africa. The path of totality started 2600km north-west of the Hawaiian Islands and made landfall over the United States mainland on the Oregon coast between Depoe Bay and Lincoln City. It then passed over northern Oregon, southern Idaho, the extreme south-western tip of Montana, central Wyoming, Nebraska, north-eastern Kansas, the south-western tip of Iowa, Missouri, southern Illinois, western Kentucky, eastern Tennessee, north-eastern Georgia, western North Carolina and South Carolina leaving the United States mainland near McClellanville. The path of totality ended 1200km south-west of Dakar in Senegal. The maximum duration of totality, 2m41s, occurred approximately 10km south-east of Makanda in Illinois. A more detailed map of the United States showing the path of totality and local circumstances for a number of locations is available.
This eclipse was also visible at sunset from the United Kingdom as a very small partial eclipse (see the diagram above). From Taunton, the eclipse started at 19:40 BST, reached maximum eclipse (4.7% obscuration) at 20:06 BST and ended at 20:31 BST, 10 minutes after sunset. The eclipsed part of the Sun set at 20:17 BST from Taunton.
Further information on all the eclipses in 2017 can be found on the Eclipses Online web pages. This web site provides information on both solar and lunar eclipses in the period from 1501 CE to 2100 CE. Global circumstances of both solar and lunar eclipses are provided as well as local circumstances of the solar eclipses based on a gazetteer of approximately 1500 locations worldwide. Eclipses for next year, 2018, are also available.
Mercury rises a little over half an hour before the Sun at the start of the month at a magnitude of −1.5 rendering it almost impossible to observe with the naked eye. It reaches superior conjunction with the Sun on Sunday October 8th and reappears in the evening twilight sky at the beginning of the last week of October. It sets not long after the Sun and is very difficult to see with the naked eye.
Venus is slowly becoming a less prominent object low in the morning twilight sky having risen in the eastern sky less than an hour before the start of morning nautical twilight. It remains at magnitude −3.9 throughout the month. Venus lies 0.2° north of Mars on Thursday October 5th and 2.0° south of the waning crescent moon on Wednesday October 18th.
Mars is visible low in the eastern morning twilight sky at the start of the month in the constellation of Leo. It crosses into Virgo in the middle of the month, rising more than an hour before the start of morning nautical twilight. Mars remains at magnitude +1.8 throughout the month. It lies 0.2° south of Venus on Thursday October 5th and 1.8° south of the waning crescent moon on Tuesday October 17th.
Jupiter sets only forty minutes after the Sun at the start of the month making a sighting unlikely. It moves into the glare of sunset reaching conjunction with the Sun on Thursday October 26th. Jupiter reappears in the morning sky in mid-November in the constellation of Virgo, remaining at magnitude −1.7.
Saturn can be seen low in the south-western sky in the mid-evening. It remains at magnitude +0.5 for the whole of the month as it moves through the eastern part of the constellation of Ophiuchus. Saturn sets in the late evening at the start of the month, setting earlier each night as the month progresses. Saturn lies 3° south of the waxing crescent moon on Tuesday October 24th.
Uranus rises in the eastern sky in the early evening as it moves towards opposition on Thursday October 19th. It lies in the constellation of Pisces close to the 4th magnitude star Omicron Piscium. Uranus is a magnitude +5.7 blue-green object visible with binoculars. This planet can also be glimpsed with the naked-eye under optimum conditions.
Neptune rises in the eastern sky in the early evening having reached opposition on Tuesday September 5th. It lies in the constellation of Aquarius close to the 4th magnitude star Lambda Aquarii. Neptune is a magnitude +7.9 object visible with good binoculars under optimum conditions. However, it can be difficult to distinguish Neptune from other stellar objects of a similar magnitude.
The rarely-spotted Zodiacal Light is best seen in the half hour or so before astronomical twilight starts in the morning or in the half hour or so after astronomical twilight ends in the evening. It is best seen when the ecliptic, the path the Sun takes in the night sky, is at a steep angle to the horizon. In northerly latitudes, this occurs in the western evening post-twilight sky in February and March and the eastern morning pre-twilight sky in September and October. The Zodiacal Light appears as a large, softly radiant pyramid of light with its base near the horizon and its axis centred on the Zodiacal constellations. It appears to be about as bright as the Milky Way, consequently a dark, unpolluted sky without haze is essential to see this phenomenon. Beware, it can easily be confused with twilight itself. In the photograph, the Zodiacal Light is on the left and the Milky Way is on the right. For Taunton, astronomical twilight starts in the morning at around 05:20 BST at the beginning of the month and at 05:10 GMT (06:10 BST) at the end of the month. The cause of this so-called "false dawn" is sunlight reflecting of a lens-shaped cloud of dust in the plane of the inner solar system.
The Orionid meteor shower is active over very nearly the whole of October and the first week of November. The shower exhibits a moderate number of fast meteors and fireballs with long trains reaching a peak of activity at the end of the third week of October. These meteors are debris connected with the orbit of Halley's Comet which is encountered by the Earth at this time of year. The new moon occurs on Thursday October 19th, very close to the peak of the shower on Saturday October 21st at around midday. This means moonlight will not interfere with the optimum early morning observation window for this shower when up to 25-30 meteors per hour can normally be observed. Occasionally, the peak rate can reach 70 meteors per hour on a 12-year period due to the influence of Jupiter. Unfortunately, we are close to the minimum of that cycle. The radiant, the point from which the meteors appear to emanate, lies on the border of Orion and Gemini. Subsidiary maxima close to the main peak of activity ensure that rates will remain high for several days around October 21st. No other regular showers exhibiting significant numbers of meteors are active this month. Further information can be found at the International Meteor Organization Meteor Shower Calendar.
It is worth noting that bright sporadic meteors and fireballs are possible at any time e.g. the fireball observed over many parts of England and Scotland on Saturday March 3rd 2012 at 21:40 GMT. Extremely bright meteors or "bolides" can also seen occasionally. Typically these objects are as bright as or brighter than the full moon. A recent example of such an object was seen over the West Country, Wales and the West Midlands on Monday June 30th 2014 at 03:04 BST.
Another loosely-related phenomenon is the re-entry of space debris from space vehicles and satellites whose orbits are decaying to the point where they burn up in the Earth's atmosphere. A recent well-reported example of this occurred at around 23:00 BST on Friday September 21st 2012.
There are a number of comets around the sky at the moment. However, most of them require telescopic assistance to see them and some may be too far south in the sky to be seen by observers based in the United Kingdom. Here is a summary of the comets that may be accessible to northern observers with binoculars.
The brightest comet currently visible in the night sky requires a small telescope to see it. C/2017 O1 was discovered on Wednesday July 19th 2017 by the All-Sky Automated Survey for Supernovae program. It reaches perihelion in mid-October when it will be a ninth magnitude object at 0.7au from the Earth. For the first half of October, it lies in the constellation of Perseus moving into Camelopardalis for the second half of October. It is currently a magnitude 9.4 object visible high in the eastern sky around midnight.
If you want to look for the International Space Station (ISS) as it passes over Taunton, please have a look at this page on the Heavens Above web site. The ISS is at least as bright as a first magnitude star and can approach the brightness of Venus. Similarly, if you want to look for the Chinese space station, Tiangong-1, have a look at this page. It has been known for some time now that Tiangong-1 will re-enter the Earth's atmosphere in an "uncontrolled manner" late in 2017. Tiangong-1 is significantly fainter than the ISS, normally as bright as a third or fourth magnitude star. Information for Tiangong-2, the latest Chinese addition to the space stations orbiting the Earth, can be found on this page. It is of a similar brightness to the larger Tiangong-1. Predictions for other satellites may also be obtained from the Heavens Above web site.
Another satellite-related phenomena to look out for are the so-called "Iridium flares". These bright flashes of sunlight reflecting off the Iridium series of communication satellites can be seen at night and also occasionally during the daytime if they are bright enough. Predictions for the next seven nights are available.
The above image is a 30 minute forecast of the location and probability of auroral activity based loosely on a model developed at Johns Hopkins' Applied Physics Laboratory known as the Ovation Aurora Forecast model. It provides estimates of the energy per unit area on the Earth's atmosphere from observations of the solar wind and interplanetary magnetic field made by the Advanced Composition Explorer satellite in conjunction with empirical relationships derived from the Defense Meteorological Satellite Program. It shows where the aurora is most likely to be seen and how bright it is likely to be. The model generates a global estimate of power, called the Hemispheric Power, deposited into the atmosphere in gigawatts (GW). For powers of less than 20GW, little or no aurora may be visible. For powers of 20-50GW, you may need to be relatively close to the aurora to see it. For values above 50GW, the aurora should be easily observable, active and mobile. For values above 100GW, this is considered to be a significant storm where the aurora may be visible from hundreds of miles away. The current prediction is downloaded when you load this page. If you want to download the latest model, simply reload this page or hit F5. If you want to see the full-sized map, please click on the above image.
The above sky chart, generated from the Heavens-Above.com web site, shows what the night sky looks like at 22:00 BST on Monday October 16th 2017 from Taunton. The night sky will look the same an hour later at 23:00 BST at the beginning of the month and an hour earlier at 21:00 BST (20:00 GMT) at the end of the month. If you want to generate your own star chart for Taunton for another date and/or time please follow this link
In October 2017, the amount of daylight (measured from sunrise to sunset) decreases from 11 hours 37 minutes at the start of the month to 9 hours 45 minutes at the end of the month. Total daylight (sunrise to sunset) for the month is 330 hours 48 minutes.
start and end times of civil, nautical and astronomical twilights.
|h m||h m||h m||h m||h m|
|** ** No phenomenon that day|
|PLEASE NOTE: These times are in Greenwich Mean Time (GMT) except between 01:00 GMT on March 26th and 01:00 GMT on October 29th when the times are in BST (British Summer Time) which is one hour in advance of GMT. Times given in red are in GMT.|
The timings in the table above should be accurate to within 1-2 minutes inside the red circle superimposed on the map shown on the left.
Rising and setting times for the Sun, Moon and planets and times of twilights for other locations can be obtained from HMNAO's Websurf web pages.
The actual times at which the Sun will just appear, or disappear, will depend on the difference of the heights of the observer and the horizon and the actual refraction, which depends on the meteorological conditions along the light path. Differences of a minute or so from the tabulated times are to be expected.
For the drivers amongst you, the "Hours of Darkness", as defined by the Road Vehicle Lighting Regulations (1989), start half an hour after sunset and end half an hour before the following sunrise. Headlights should be used during the Hours of Darkness and sidelights in the half hour periods after sunset and before sunrise. These timings can also be obtained from HMNAO's Websurf web pages using the Rise, Set and Twilight Times option.
For the VFR (Visual Flight Rules) pilots amongst you, night, according to Statutory Instrument 2009 No. 3015, Civil Aviation, The Air Navigation Order 2009, Part 33 (Interpretation), Article 255(1), means "the time from half an hour after sunset until half an hour before sunrise (both times inclusive), sunset and sunrise being determined at surface level". In other words, the night period starts at the beginning of the Hours of Darkness and finishes at the end of the Hours of Darkness.