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:
The Earth reaches perihelion, the point closest to the Sun in its orbit, on Wednesday January 3rd at 05:35 GMT when it is 147,097,233km from the Sun.
Additional information on phases of the Moon, seasons, summer times, eclipses, chronological cycles and eras, religious holidays, the United Kingdom civil calendar and holiday dates can be found in HMNAO's Astronomical and Calendarial Sheet for 2018. This is a pdf document for which a document reader can be downloaded by clicking on the Adobe Reader icon above.
This web page can also be accessed from outside the UK Hydrographic Office on http://astro.ukho.gov.uk/nao/taunton.html.
↻ The last update to this page was made on Tuesday, 2018 January 23 at 09:01:38 GMT.
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 Sun has been devoid of active regions for the past seventy-two hours, bringing the total number of spotless days for 2018 to ten or 43% of the year so far. There is a long canyon-shaped coronal hole crossing the Sun's disk from the south polar region to the north-western equatorial limb. The Earth lies inside a stream of charged particles, moving at approximately 500km/s, emanating from this feature. For the past couple of days, auroral displays have been seen in the polar regions of the Earth, such as those seen on Sunday January 21st in Tromsø and the Lofoten Islands in northern Norway. The size of the coronal hole means that these displays could last for several days to come. The remains of active region AR2696 erupted on January 22nd at 03:00 UT generating a minor B9-class solar flare. The position of former sunspot means that the resulting coronal mass ejection is unlikely to hit the Earth. 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 for January 2018 are as follows:|
|Full Moon||—||Tuesday January 2nd at 02:24 GMT
Largest Full Moon of 2018 / "Supermoon"
|Last Quarter||—||Monday January 8th at 22:25 GMT|
|New Moon||—||Wednesday January 17th at 02:17 GMT
|First Quarter||—||Wednesday January 24th at 22:20 GMT|
|Full Moon||—||Wednesday January 31st at 13:27 GMT
Calendrical Blue Moon for January / "Supermoon"
The Moon is at perigee (closest to the Earth) on Monday January 1st at 21:49 GMT when it is 356,565km from the Earth. It is at apogee (furthest from the Earth) on Monday January 15th at 02:10 GMT when it is 406,464km from the Earth. It is again at perigee on Tuesday January 30th at 09:57 GMT when it is 358,994km 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 both the beginning and end of January leads to "perigean spring tides" i.e. spring tides with a tidal range somewhat higher than those of normal spring tides.
On Friday January 5th, the Moon occults Regulus, the bluish-white first-magnitude star in the constellation of Leo. This occultation is visible from Alaska, the eastern tip of Russia, northern Canada, the Arctic Ocean region, Greenland, Svalbard, Iceland, Scandinavia, most of Europe and north-western Africa. This daylight occultation is visible from the United Kingdom for those with telescopes. From Taunton, the occultation by the waning gibbous moon starts at 08:25 GMT, ten minutes after sunrise and ends at 09:20 GMT, an hour and ten minutes before moonset.
On Saturday January 27th, 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 most of India, central Asia, most of China, Mongolia, most of Russia, Alaska and north-western parts of North 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.
Many of you will have heard of the term "Blue Moon" in phrases such as "once in a blue moon" meaning a rare or infrequent event. Some of you may be aware that this month's second full moon is being called a blue moon.
There are two "definitions" of a blue moon describing an extra full moon in a subdivision of a year. One refers to the third of four full moons in a season and, more recently and erroneously, the second full moon in a calendar month. This definition came from an article in the March 1946 edition of Sky & Telescope by James Hugh Pruett and was propagated until 1999 by this well-known astronomy magazine. If you divide the year up into quarters using solstices and equinoxes as limiting dates then the blue moons are termed "seasonal". If you adopt calendar months as your criterion, where two full moons occur in a month, then the blue moons are termed "calendrical".
The blue part of the name has nothing to do with the colour of the Moon, although on very rare occasions smoke and/or dust in the atmosphere can give the moon a bluish tint. The term blue moon may be linked to the belief that this second moon was a betrayer moon or "belewe" moon in the determination of Lent.
Blue moons of both types are listed in sequential order for the period 2000 to 2040 in the table below.
|Year||Full Moon||Year||1st Full Moon||2nd Blue Moon|
|2000||February 19||2001||November 1||November 30|
|2002||August 22||2004||July 2||July 31|
|2005||August 19||2007||June 1||June 30|
|2008||May 20||2009||December 2||December 31|
|2010||November 21||2012||August 2||August 31|
|2013||August 21||2015||July 2||July 31|
|2016||May 21||2018||January 2||January 31|
|2019||May 18||2018||March 2||March 31|
|2021||August 22||2020||October 1||October 31|
|2024||August 19||2023||August 1||August 31|
|2027||May 20||2026||May 1||May 31|
|2029||August 24||2028||December 2||December 31|
|2032||August 21||2031||September 1||September 30|
|2035||May 22||2034||July 1||July 31|
|2038||May 18||2037||January 2||January 31|
|2040||August 22||2037||March 2||March 31|
|2039||October 2||October 31|
The above timings are predicated on GMT-based dates. Whichever scheme one adopts, a blue moon is not as rare an event as it might seem. In fact, seasonal blue moons happen seven times in nineteen years or once every 2.7 years.
You can also have a "Black" moon; there are several definitions for this type of moon. One is the second occurrence of a new moon in a calendar month. It can also be the third new moon in a season of four new moons. Both of these are analogous to the blue moon definitions. The third is the absence of a full moon in a calendar month and the fourth is the absence of a new moon in a calendar month. The last two can only happen in February in addition to the previous January and the following March having two full or new moons respectively. Next month, February 2018, is an example of the third definition which occurs about once every 19 years.
Some people may have heard of "dry" moons and "wet" or "Cheshire" moons, where the cusps or horns of the crescent point upwards. In the northern hemisphere, the dry moon is a summertime moon whereas the wet moon is a wintertime one. Both of these terms are thought to come from Hawaiian astrology where the crescent moon is regarded as a bowl for collecting water.
Folklore has also given us a plethora of names for each month's Full Moon. Here are a selection of names from a variety of cultures including Native American Indian, Colonial American, Pagan and English Medieval. I should point out that this list is by no means an exhaustive one.
|Month||Full Moon names|
|January||Wolf / Cold / Chaste / Old / Ice|
|February||Snow / Storm / Hunger / Chaste / Wolf|
|March||Worm / Crow / Sap / Chaste / Lenten / Death / Crust / Sugar|
|April||Pink / Paschal / Seed / Sprouting Grass / Egg / Fish / Hare|
|May||Flower / Milk / Mother's / Hare / Corn Planting|
|June||Strawberry / Mead / Rose / Dyan / Thunder / Hot|
|July||Buck / Hay / Wort / Summer / Thunder|
|August||Sturgeon / Corn / Red / Fruit / Green Corn / Grain / Barley|
|September||Harvest / (Full) Corn / Barley|
|October||Hunter's / Dying Grass / Blood / Sanguine / Falling Leaf / Travel / Harvest|
|November||Beaver / Frost / Snow / Mourning / Oak / Hunter's|
|December||Cold / Winter / Oak / Long Night|
In the previous "The Moon" section, you may have noticed that the first full moon of the month occurs 4 hours and 35 minutes after the time of perigee. Consequently, we can be fairly certain that the word "Supermoon" will be used to describe this month's first full moon. There is also a second full moon in January where full moon occurs 27.5 hours after the time of perigee. This, too, will probably be referred to as a supermoon.
The term Supermoon was coined in 1979 by astrologer Richard Nolle. He defined it as "a new or full moon which occurs with the moon at or near (within 90 percent of) its closest approach to Earth in a given orbit", without explaining why the 90 percent figure was chosen. As the Moon's orbit is elliptical, not circular, there is a point in its orbit where it is closest to the Earth (perigee) and another one where it is furthest away from the Earth (apogee) and these perigee and apogee distances change somewhat from one orbit to another. In the period between 1850 and 2050, perigee distances for the Moon range from 356,375km to 370,355km while apogee distances range from 404,055km to 406,710km.
The closest full moons occur on average in cycles of just over a year as 14 lunar months or lunations are almost equal to the time taken for 15 returns to perigee. The full moon of 2017 December 3rd took place at distance of 357,983km. The 2018 January 2nd and January 31st full moons take place at distances of 356,602km and 360,198km respectively. Similarly, the run of 2016 full moons of October 16th, November 14th and December 14th all took place at distances of less than 360,000km from the Earth. We might say that the supermoon of November 14th is "more super" than the other 2016, 2017 and 2018 supermoons as it lay at a distance of only 356,520km from the Earth. In fact, the November 2016 event was the closest full moon until that of November 25th 2034 when the Moon will be at a distance of 356,446km from the Earth. The last time the Moon was at a similar distance to this occurred on 1948 January 26th when it reached a minimum distance of 356,491km.
|The Fifteen Closest Full Moons: 1850-2050|
Many media articles will mention that the Moon will be 14% bigger and 30% brighter than when the full moon occurs furthest from the Earth or 7% bigger and 15% brighter than average. A nice illustration of this can be seen on the Astronomy Picture of the Day site. As a result of these differences, you might expect to see a significantly bigger and brighter Moon but this is not the case. The transition between an apogee full moon and a perigee full moon takes place over seven lunar cycles so the apparent changes in size from one full moon to the next are only perhaps 2% in apparent size and 3% in apparent brightness. These kinds of changes are more difficult to detect. Indeed, discerning changes in the size of the Moon is even more difficult to detect when the Moon is close to the horizon due to the so-called "Moon Illusion". On a given night, the rising or setting Moon will appear larger than when it is high in sky. There is no proper explanation for this perceived difference but it may be related to the presence of perceptual cues for the eye near the horizon which are missing for an object much higher in the sky.
Is the supermoon just another piece of media hype? Have you also noticed the increasing use of the term "Micromoon" for the smallest full moon in a given period of time? Neil de Grasse Tyson, the director of the Hayden Planetarium in New York, has suggested that supermoons are indeed over-hyped. "I don't know who first called it a Supermoon," he told StarTalk radio. "I don't know but if you have a 16-inch pizza, would you call that a super pizza compared with a 15-inch pizza?". Enough said ...
There are five eclipses in 2018, two are total eclipses of the Moon and the remaining three are partial eclipses of the Sun. One total eclipse of the Moon is visible in the United Kingdom, namely that of 2018 July 27th. One partial eclipse of the Sun is also visible from the northernmost parts of the United Kingdom on 2018 August 11th.
A total eclipse of the Moon occurs on Wednesday January 31st 2018. It will be visible in its entirety from Alaska, western Canada, the Hawaiian Islands, western Polynesia, Melanesia, Micronesia, most of Australia, New Zealand, eastern Indonesia, the Philippines, eastern China, Japan and eastern Siberia. Western parts of the United States, western China and India will also see the total phase of the eclipse. The eclipse ends just before moonrise in the United Kingdom so it will not be visible in Taunton.
A partial eclipse of the Sun will occur on Thursday February 15th 2018. It will be visible in its entirety from most of Antarctica except parts of eastern Antarctica including Enderby Land, American Highland and Wilkes Land, and the southern part of South America including Argentina and the southern half of Chile. This eclipse is not visible from the United Kingdom.
A partial eclipse of the Sun will occur on Friday July 13th 2018. It will be visible from the easternmost part of Wilkes Land in Antarctica, the southern tip of New Zealand and the southernmost parts of South Australia and Tasmania. This eclipse is not visible from the United Kingdom.
A total eclipse of the Moon will occur on Friday July 27th 2018. It will be visible in its entirety from the Indian Ocean region, westernmost China, India, the Middle East, central Asia, Turkey and the eastern half of Africa. Most of Australia, the Philippines, Indonesia, most of China, western Africa and most of Europe will see the total phase of the eclipse. Some of the total phase of the eclipse is visible from the United Kingdom as the Moon rises during the umbral part of the eclipse. In Taunton, the Moon rises at 21:00 BST, approximately halfway between the start of the total phase at 20:30 BST and the middle of the total phase at 21:22 BST. The Moon will rise in a totally-eclipsed state and we will see about three quarters of the total phase of the eclipse.
A partial eclipse of the Sun will occur on Saturday August 11th 2018. It will be visible in its entirety from north-easternmost parts of Canada, Greenland, Iceland, northern Scotland, Scandinavia except Denmark, most of Russia except the south-western and eastern parts, and central Asia. In the United Kingdom, this eclipse is visible from the northernmost parts of Scotland, the Orkney Islands and the Shetland Islands as a very small partial eclipse with an obscuration of less than 1.8%. The eclipse will last 30 to 40 minutes with maximum obscuration occurring at around 9:49 BST. This eclipse will not be visible in Taunton.
Further information on all the eclipses in 2018 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, 2019, are also available.
Mercury is visible very low in the south-eastern morning twilight sky shortly before the start of civil twilight at the beginning of the month. It gets lower in the sky as the month progresses. It reaches greatest western elongation on Monday January 1st when its magnitude is −0.4. Mercury then brightens somewhat to −0.6 by the end of January. It lies 0.6° south of Saturn on Saturday January 13th and 3° south of the waning crescent moon on Monday January 15th.
Venus is too close to the Sun to be observed this month. It will not reappear in our skies again until the end of the third week of February 2018 when it will be visible, perhaps with difficulty in the twilight glow, as a brilliant object in the western twilight sky at the end of evening civil twilight.
Mars rises three and a half hours before the start of morning nautical twilight in the east south-eastern twilight sky moving towards its close conjunction with Jupiter on January 7th in the constellation of Libra. It passes close to the third magnitude double star Zubenelgenubi (now strictly known as α2 Librae) during the first week of January. Mars brightens somewhat from magnitude +1.5 at the start of the month to +1.2 at the end of January. It lies 0.2° south of Jupiter on Sunday January 7th and 5° south of the waning crescent moon on Thursday January 11th.
Jupiter rises nearly four hours before the start of morning nautical twilight in the east south-eastern twilight sky moving towards its close conjunction with Mars on January 7th in the constellation of Libra. It brightens somewhat from magnitude −1.8 at the start of the month to −2.0 at the end of January. Jupiter lies 0.2° north of Mars on Sunday January 7th and 4° south of the waning crescent moon on Thursday January 11th.
Saturn is visible in the morning twilight sky in the second half of the month after its conjunction with the Sun on Thursday December 21st 2017. It lies in the constellation of Sagittarius where its magnitude remains constant at +0.5 for the whole of January. During the second half of January, it rises in the south-eastern sky around the beginning of nautical twilight. Saturn reached the southernmost point of its 29.5 year orbit period at the end of December 2017 and will not be this far south in the sky again until November 2047.
Uranus rises in the east north-eastern sky in the late morning and is due south in the sky at the end of evening nautical twilight. It lies in the constellation of Pisces approximately 3.5° to the west of the 4th magnitude star Omicron Piscium. Uranus is a magnitude +5.8 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 late morning and lies in the south-western sky about an two hours or so after sunset. It lies in the constellation of Aquarius approximately 0.8° to the east of the 4th magnitude star Lambda Aquarii. Neptune is a magnitude +7.9 object visible with good binoculars under optimum conditions. However, please note that it can be difficult to distinguish Neptune from other stellar objects of a similar magnitude.
Pluto lies in the constellation of Sagittarius and is too close to the Sun to be observed this month. Strictly speaking, this is a dwarf planet as it got demoted from the ranks of the "bona-fide" planets in 2006. I have to confess that I was one of those astronomers that voted for its demotion at the IAU General Assembly in Prague! At magnitude +14.6, you are going to need a much more serious telescope to see this remote member of the Solar System.
The Quadrantid meteor shower is active from Thursday December 28th 2017 to Friday January 12th 2018 although the shower reaches a very sharp peak of activity on the evening of Wednesday January 3rd around 22:00 GMT. The shower generates approximately 110 meteors per hour for around eight hours either side of the maximum. This shower is well known for producing fireballs and bright meteors with persistent trails. Sadly, the peak of the shower this year occurs close to full moon on January 2nd which means that strong moonlight will have a fairly drastic affect on the number of meteors you are likely to observe in 2018.
The radiant, the point from which the meteors appear to emanate, lies between the "tail" of Ursa Major, the head of Boötes, the Herdsman and the tail of Draco, the Dragon in the now-defunct constellation of Quadrans Muralis, the Mural Quadrant – hence the unusual name of the shower. The optimum time to observe the peak of this meteor shower in 2018 is to go out in the early evening of January 3rd looking towards the north north-east at an altitude of only 10°. The radiant gets higher as the night progresses reaching an altitude of 45° in the east north-eastern sky about 04:00 GMT.
These meteors are thought to be related to the asteroid 2003 EH1, an extinct comet which in turn may be related to a comet known as C/1490 Y1. This comet was first recorded by Chinese and Korean astronomers 500 years ago and probably disintegrated a century or so later. This makes the Quadrantids one of only two showers that are not connected directly with a comet – the other being the Geminids which were visible last month. No other showers exhibiting significant numbers of meteors are active this month. Further information can be found at the International Meteor Organization and their 2018 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. Larger events, known as bolides, are rarer. Typically, this is a very bright fireball reaching an apparent magnitude of −14 or so, perhaps three times as bright as a full moon. Even rarer are the superbolides, events with apparent magnitudes of −17 or so, around 50 times brighter than the full moon. A recent example of a superbolide was the Chelyabinsk meteor of 2013 February 15th at 03:20 UTC which may have been a 20-metre diameter near-Earth asteroid.
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 couple of well-reported examples of this occurred at around 23:00 BST on Friday September 21st 2012 as well as the return of the GOCE satellite just after midnight on Tuesday November 12th 2013.
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 or small telescopes in the northern hemisphere.
The brightest comet currently visible in the night sky requires a small telescope such as a 75mm refractor or 150mm reflector to observe it. 62P/Tsuchinshan 1 was discovered on January 1st 1965 at the Purple Mountain Observatory in Nanjing, China. It has a period of 6.6 years and reached perihelion in early December 2017 when it was a tenth magnitude object in the constellation of Virgo. 62P/Tsuchinshan 1 still lies in the central part of Virgo and will continue to do so for the whole of January. However, it is likely to fade to around eleventh magnitude and will be visible in the south-eastern sky before morning twilight.
A possible target for the observer with access to a small telescope is the rapidly-moving comet C/2017 T1 Heinze. It will be closest to the Earth on January 4th, when it will be some 33 million kilometres from the Earth and may reach a magnitude of 9.3. During January, it will pass through the constellations of Lynx. Camelopardalis, Cassiopeia, Andromeda, Lacerta and Pegasus. It was discovered on 2017 October 2nd and will reach perihelion on 2018 February 21st. The magnitude of this comet would suggest that it exceeds the Bortle survival limit for comets, indicating that it may not survive its passage through perihelion. Nevertheless during January, it should be visible fairly high in the early evening sky, starting in the north-eastern sky, then passing overhead and then moving into the south-western sky towards the end of January.
The tenth-magnitude comet C/2016 R2 PANSTARRS has recently exhibited some unusual behaviour. For those of you with access to a small telescope, it may be of interest to take a look at this comet. It starts the month in Taurus, close to the first magnitude star, Aldebaran, and the Hyades cluster, and moves towards the Pleiades cluster as the month progresses. In this photograph, the comet lies between the 4th magnitude star Gamma Tauri (bottom left) and the seventh magnitude star HD27029 (top right). It has a very strong blue colour indicative of significant quantities of ionised carbon monoxide, CO+, fluorescing under the influence of sunlight in its orbit just outside that of Mars. It has a chaotic tail fed by jets from the comet's core; the tail also exhibits swirls of material and an unusual knee-shaped feature. The comet can be seen high in the southern sky in mid-evening and there is plenty of scope for more volatility as carbon monoxide-rich C/2016 R2 reaches perihelion on 2018 May 9th.
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" in late January/early February 2018. 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 Tuesday January 16th 2018 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 January 2018, the amount of daylight (measured from sunrise to sunset) increases from 8 hours 0 minutes at the start of the month to 9 hours 11 minutes at the end of the month. Total daylight (sunrise to sunset) for the month is 263 hours 50 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 25th and 01:00 GMT on October 28th 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.