This page provides some astronomical information on a monthly basis for those of you living in the Taunton area. Timings are in GMT (Greenwich Mean Time) unless otherwise noted. Latest additions or updates are highlighted with a red border.
This month we have sections on:
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 is devoid of sunspots for the third day in a row. The Sun has been blank for a total of eighty-four days during 2017 or 25% of the year so far. A small coronal hole close to the western limb of the Sun's disk is emitting a stream of solar wind which reached the Earth late on November 20th. Solar winds moving at around 500km/s have initiated minor G1-class geomagnetic storms causing bright auroral displays in the polar regions of the Earth, particularly in the Lofoten Islands, northern Norway and Finland. The Earth is likely to be in the stream of solar wind for another day or so. 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. Space weather will be dominated by solar winds and cosmic rays rather than sunspots and solar flares.
The sequence of Moon phases for this month and their designations are shown in the following animation:
Moon phases specific to November 2017 are as follows:
Full Moon – Saturday November 4th at 05:23 GMT
Last Quarter – Friday November 10th at 20:36 GMT
New Moon – Saturday November 18th at 11:42 GMT
First Quarter – Sunday November 26th at 17:03 GMT
The Moon is at perigee (closest to the Earth) on Monday November 6th at 00:10 GMT when it is 361,438km from the Earth. It is at apogee (furthest from the Earth) on Tuesday November 21st at 18:53 GMT when it is 406,132km from the Earth.
The combination of the Moon being at perigee and the phase of the Moon being either new or full as it is at the end of the first week of November leads to "perigean spring tides" i.e. spring tides with a tidal range somewhat higher than those of normal spring tides.
On Monday November 6th, 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 North America except the westernmost parts, Greenland, Iceland, northern Europe, the Arctic region and north-west Asia. This occultation is visible from the United Kingdom. From Taunton, Aldebaran is occulted by the last quarter moon at 02:36 GMT and reappears at 3:19 GMT.
On Saturday November 11th, the Moon occults Regulus, the bluish-white first-magnitude star in the constellation of Leo. This occultation is visible from Japan, eastern Asia, the Aleutian Islands, southern and western parts of North America, the northern Caribbean region and Central America. 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 is visible in the south-western evening twilight sky for the whole of the month, setting around the end of evening civil twilight. Its magnitude lies in the range −0.3 to −0.4 for the whole of this interval. Mercury lies 2° north of Antares on Sunday November 12th and 7° south of the new crescent moon on Monday November 20th. Mercury reaches greatest eastern elongation on Friday November 24th and lies 3° south of Saturn on Tuesday November 28th.
Venus is slowly decreasing in prominence as the month progresses and its visibility window shortens. It rises in the east south-eastern sky during morning astronomical twilight, remaining at magnitude −3.9 throughout the month. Venus lies 4° north of Spica on Wednesday November 1st, 0.3° north of Jupiter on Monday November 13th and 4° south of the waning crescent moon on Friday November 17th.
Mars is visible low in the eastern morning twilight sky in the constellation of Virgo, rising more than an hour before the start of morning astronomical twilight. It fades slightly from magnitude +1.8 at the start of the month to +1.9 at the end of November. Mars lies 3° south of the waning crescent moon on Wednesday November 15th and 3° north of Spica on Tuesday November 28th.
Jupiter reappears out of the glare of the Sun and into the morning twilight sky in the latter half of the month at a magnitude of −1.7. It will be 0.3° south of Venus on Monday November 13th, the conjunction potentially being visible telescopically during daylight hours. Jupiter crosses the border between the constellations of Virgo and Libra on Tuesday November 14th.
Saturn can be seen low in the south-western sky in the early evening at the beginning of the month. It remains at magnitude +0.5 for the whole of the month as it moves out of the eastern part of the constellation of Ophiuchus into Sagittarius on Sunday November 19th. Saturn sets earlier each evening as the month progresses before disappearing into the evening twilight at the beginning of December. Saturn lies 3° south of the waxing crescent moon on Tuesday November 21st.
Uranus rises in the east north-eastern sky well before sunset having reached opposition on Thursday October 19th. It lies in the constellation of Pisces not too far from 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 east north-eastern sky in the early afternoon 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 Leonid meteor shower is active from Monday November 6th to Thursday November 30th. The shower typically exhibits a small number of meteors reaching a peak of activity this year on Friday November 17th at around 17:00 GMT. These meteors are related to the comet 55P/Tempel-Tuttle which last reached perihelion (the comet's closest approach to the Sun) in February 1998 when the shower generated around 500 meteors per hour on November 16th and 17th. The Leonids are known to be variable in the number of meteors they produce — in 1966 they generated around 40 meteors per minute for an interval of around 15 minutes over the United States. The maximum of the display takes place at new moon this year. Observations of the shower in the early hours of Friday November 17th will be unaffected by moonlight and around 15-20 meteors per hour can normally be observed in such favourable conditions. The radiant, the point from which the meteors appear to emanate, lies within the "Sickle" (head) of Leo. No other showers exhibiting significant numbers of meteors are active this month. Further information can be found at the International Meteor Organization and their 2017 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 brief summary of the comets that may be accessible to observers with binoculars in the northern hemisphere.
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 reached perihelion in mid-October when it was a ninth magnitude object at 0.7au from the Earth. For the first half of November, it lies in the constellation of Camelopardalis moving into Cepheus for the second half of the month. It is currently a magnitude 9.4 object visible fairly high in the northern sky in the early hours of the morning.
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 GMT on Wednesday November 15th 2017 from Taunton. The night sky will look the same an hour later at 23:00 GMT at the beginning of the month and an hour earlier at 21:00 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 November 2017, the amount of daylight (measured from sunrise to sunset) decreases from 9 hours 41 minutes at the start of the month to 8 hours 18 minutes at the end of the month. Total daylight (sunrise to sunset) for the month is 268 hours 5 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.|
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 altitudes of the observer and the local 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 time period starts at the beginning of the Hours of Darkness and finishes at the end of the Hours of Darkness.