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🚄 | Oigawa Railway "Starry Sky Train" to "Starry Sky Express" Eight passenger cars will be connected this season

Photo Conventional "starry sky train" image (Photo: Oigawa Railway)

Oigawa Railway "Starry Sky Train" to "Starry Sky Express" Eight passenger cars will be connected this season

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After enjoying the starry sky observation for about an hour at the station, return to Senzu station.

On October 2021, 10, Oigawa Railway announced the operation plan of "Starry Sky Express".20 this season ... → Continue reading

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Astronomical observation

Astronomical observation(Tentai Kansoku)Celestial bodyThe operation and changes of itself and celestial bodiesObservationIt is to be.天体観測はAstronomical observationNaked eyeStarting from looking up at the night skybinocularsOr smalltelescopeFrom observations made as a hobby usingobservatoryIt is widely used for observations using a large telescope and special observation equipment.観測は主にObservation is mainly地球Besides being done from aboveOrbit of artificial satelliteIt is also done from above.主たる観測対象はThe main observation target is星座,star,meteor,火星,VenusSuch as惑星OrMonthThe fullness of the stars, the movement of stars, etc.astronomyBegins with astronomical observations, and physical exploration of celestial phenomena is carried out by data analysis and hypothesis verification.

History of astronomical observation

Old timesEgyptian civilization,Inca civilizationHowever, it is said that astronomical observations were carried out, the calendar and time were measured by the operation of celestial bodies, and the agricultural calendar, which is indispensable for agriculture such as seasons, was also created.pyramidStructure, traces of the Inca Observatory, orEuropeButStonehengeAmong the megalithic ruins such asspring equinox,Autumn equinoxYou can see the structure of the sequence that indicates that you were observing.Later, as shipping developed, the stars were also used as a guide to know the direction at night.Polaris-Big Dipper TheNorthIt is a typical celestial body that points in a direction.

GreekAncientphilosopher,ThalesHad a deep knowledge of astronomical observation.天体を眺めながら夜道を歩いていて転んだところを、人に笑われて、次のシーズンのPeople laughed at the place where I fell down while walking on the night road while looking at the celestial bodies, and the next season穀物It is said that he predicted the pattern of the product and made a big profit by speculation.また、かなり古い時期から、生まれた時のAlso, from a very old age, when I was born星座Fortune-telling through celestial bodies such as the state ofastrologyAlso developed.

Astronomy has advanced through the accumulation of astronomical observations.As an example,Ptolemaic morningEgyptNaturalistEratosthenesBy地球It was also done to measure the size of.記録によれば、エジプトのAccording to records, EgyptianThebesとAlexandriaWith(I.e.I learned from the story of a traveler about the difference in the projection angle of the shadow of the Earth, and tried to find the size of the earth by measuring the distance between Thebes and Alexandria.This is believed to be the first attempt to measure the size of the Earth (related item:Geodesy).

Italian physicistGalileo GalileiIs a Dutch eyeglass craftsmanHans LipperheyInvented bytelescopeWas applied and turned to the sky.It is believed that this is the beginning of the dramatic evolution of astronomical observations from the naked eye to astronomical telescope observations (related item:observatory,Astronomical telescope).

Also in JapanFujiwara Teikeof"TomorrowToSupernovaSN1054(TaurusCrab Nebula) Is recorded.At that timeSupernovaWas recorded as a guest star.cometEtc. may remain as similar records.

ChugokuThen,æ¼¢During the dynastySunspotThere is a record of.In other words, it is a scientific study that has been conducted all over the world since recorded history (Related item:Astronomy history).

Application of astronomical observation

Times of Day
Especially famousSundial.(I.e.You can know the time by observing the operation of.As an application of thisMeridianBy measuring the celestial body above, you can know the regional standard time of the position.ここに補正を加えることで、過去にはBy adding a correction here, in the pastJapan Standard TimeThe standard time was decided.現在は、標準Currently standardAtomic clockThe standard time is determined by adding the motion correction time of the earth rotation obtained from the astronomical observation to the fixed time ticked by.The regional standard time is set by adding or subtracting the correction time stipulated by law.
By observing the movement of the constellations, it is possible to know the sowing season of agricultural products.例えばFor exampleSpicaMeans the ear of wheat, and you can see the arrival of the sowing season for wheat by looking at this star.日本ではin JapanArcturusHits wheat star.It was created based on this wisdom, and there is also an agricultural calendar.
You can know your position by observing the direction and angle of the sun and constellations.Currently,GPSSince the replacement has progressed to, there are few opportunities to see or utilize the real thing,Octant,sextantThere was a method of observing the position of the celestial body with equipment such as, and knowing the position from the observation time.As the origin of this observation time, GMT (Greenwich Mean Time) Was used.
Planetary exploration
The planetary probe is located on the North Pole or South Pole of the ecliptic plane (it is on the South Pole side because it is not on the North Pole side).Canopus) Equipped with a sensor that selects a celestial body as the reference coordinate and observes the star.With this sensor, the planetary probe will head toward the target celestial body, relying that the spacecraft's orbit is on the ecliptic plane.

Modern astronomical observation

Astronomical observation research field

visible lightOther than that, astronomical observations are also carried out, and there are the following observation research fields.

Mainly large equipment is used.

In addition, some observers are observing meteor showers using FM radio, and using antennas for BS / BS broadcasting or antennas for VHF communication to observe solar radio waves.

Spread to the general public

Hobbies,outdoor activitiesAs part of, astronomical observations are being carried out.It is an astronomical observation that does not leave observations in data or records.Astronomical observation, Also called celestial appreciation.observatory,Museum"Star observation party" held byCampRather than research, such as star watching atSocial education,レ ク リ エ ー シ ョ ンIt is also done on the typical side.夏季にはIn summerPerseids meteor showerA viewing party called "Star Festival" is held in various places after Tanabata, Star Week, etc., and many people gather to observe astronomical objects.In addition, in the case of large celestial phenomena that are taken up in news and meteorological information, astronomical observation meetings are held by various astronomical research groups, and many people make observations.

Ministry of the EnvironmentThen,Nationwide starry sky continuous observationThe project is held twice each year, in summer and winter.天体観望からFrom astronomical observationLight pollution,Air pollution such asEnvironment issuesIt raises interest in.others,observatoryStarting withMuseum,planetariumCommentary on, appearance on TV programs,Astronomical magazineThe dissemination activities are carried out by writing and supervising the dissemination books.In particular, many people are active in this field by photographing celestial phenomena, activities for that purpose are being carried out, and many books have been published.

As a prominent person in this fieldIsobe Ryuzo,Murayama Sadao,Masaki Morimoto,Akira Fujii, Etc.

Mainly stored in shrines and precincts around the worldmeteoriteIntroduction and smallAstronomical telescopeBut it is possible enough.

2009 isWorld Astronomical Year 2009At public observatories around the worldplanetariumRelated events will be held at.

From new celestial body discovery to confirmation

When you discover a new object in Japan, basicallyNational ObservatoryorNakano ShuichiWill be contacted at the office.The National Astronomical Observatory of Japan will be contacted by other observatories and other observers and will begin mutual verification to determine the type of the object.First, contact the Astronomical Central Telegram Office.ここからの連絡を受けて、各国の観測所では、発見者が連絡した観測点から推定される天体を観測して、軌道計算を行い、天体のIn response to the contact from here, the observatories in each country observe the celestial body estimated from the observation point contacted by the discoverer, calculate the orbit, and calculate the orbit of the celestial body.Photometric observationDetermine the type by.

In addition, astronomical observers who participate in each astronomical study group directly through those who are performing orbit calculation etc. at the astronomical study group.Smithsonian Astrophysical ObservatoryThere is no problem if you contact (Astronomical Central Telegram Bureau).This is because the Astronomical Central Telegram Bureau is supposed to contact the central observatories of each country.

From there, in the case of asteroids, contact the Minor Planet Center, and in the case of comets, contact the International Comet Quarterly Report.And惑星(小 惑星-cometIn the case of (including), etc., observations will be made to determine the orbit, and the procedure for registering the discovered celestial body as a new celestial body will be started.

If the object is a comet, the registered object will be named after the discoverer.In the case of an asteroid, the discoverer is given the right to propose a name.In the case of satellites, the naming convention is strict, but the wishes of the discoverer may be taken into consideration.There are no rules regarding the discovery of planets yet.

As a prominent person in this fieldHonda Minoru,Kaoru Ikeya,Tsutomu Seki,Nakano ShuichiEtc.

Published because it requires a certain amount of large equipmentobservatoryThis is a field in which those who are conducting astronomical observations as a profession or observing in Japan participate.


  • Ko Nagasawa "Yes, this is the National Astronomical Observatory-Telephone Counseling Room in the Starry Sky" Shinchosha.
  • Ko Nagasawa "Telephone number of the observatory National Astronomical Observatory Public Relations Office" Chijin Shokan.
  • Ko Nagasawa "Astronomical Position Calculation Augmented Edition" Chijin Shokan.
  • Shuichi Nakano "Calculation of celestial orbits" Seibundo Shinkosha.
  • Ichiro Hasegawa "Introduction to Astronomical Calculation-From Spherical Calculation to Orbital Calculation" Seiseisha Koseikaku.

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field of study

Observation facility

Observation equipment

Related information

外部 リンク

Time unit)

Time(Jikan) or时(The sign:h) IsTime Ofunitone of.SI combination unit(International unit systemCan be used with (SI)Non-SI unit)[1].. In addition, SI and JapanMeasurement LawThen, the name of the unit is only "hour", not "hour"[2].

In Japanese,Times of DayaboutTimeIs used, and when referring to the time interval, it is usually "Time”Is used. Also in the same kanjiTimeThe word read as is a unit in the old Japanese hour system. See the section on indefinite time below.

One hour historically地球At 1Day(More accurately 1 averageSolar day) Has been defined as a 1/24 time interval.Currently, seconds are the basic unit of time, so one hour is defined as "1 times seconds." 3600 for 1 hourMinute.

Unit symbol Of h It is,1948 The 9thInternational Weights and Measures General AssemblyIt was stipulated by Resolution 7 of (CGPM). Others such as hr may be used,International unit system(SI) and JapanMeasurement LawIn the system, only the symbol "h" is allowed and no other symbols may be used[3].


Ancient civilizations around the world (Egypt,Mesopotamia,Indus,Yellow River) Is used to divide the timesunriseAnd between sunset (or dawn and sunset)12Divide or divide the day by twice 124It was a divided item. 12 times 12144It wasn't a split. In any case, the split is a multiple of 12, which isMonth,directionIt has also been used for such purposes.

Until the definition of the current time was decided, the definition changed as follows.

Indefinite time method

Initially, 1/12 from sunrise to sunset (or from dawn to sunset) is 1 hour (in Japan,1/6 Was set to 1 o'clock (when). Therefore, the length varies greatly depending on the season, and one hour (1 o'clock) in the daytime is long in summer and short in winter. It also depends on the latitude, but this was not a problem while the range of human activity was narrow. At this timeIndefinite time methodThat is. In East Asia, the indefinite time method was used until the early modern period.

Fixed time method

Later, 1/24 of the visible solar day (between noon and the next noon, or between nightfall and the next nightfall) was set to 1 hour.This reduced the seasonal variation in the length of one hour, but the length of the solar day was still slightly different depending on the season, so it was necessary to adjust the clock several times a month.

after that,Average sun day1/24 is now 1 hour.With this, the length of one hour seemed to be constant, butRotation of the earthIs not constant, 10-8orderFluctuation (1 day = 86400It turns out that there are about 1 to 2 milliseconds per second), and this definition is no longer used.For the subsequent changes in the definition and "length of day", see "second""Leap second""Rotation of the earth"checking.


  1. ^ Translation and supervision (Germany)National Institute of Advanced Industrial Science and Technology Metrology Standards Center "International Document 8th Edition (2006) International System of Units (SI) Japanese Edition(PDF), page 36.ISBN 92-822-2213-6.2016/4/12Browse. "Table 6 Non-SI Units Used with SI Units"
  2. ^ Measurement Law Appendix XNUMX "Time" column of "Amount of physical condition"
  3. ^ Unit of Measure Regulations (November XNUMX, XNUMX Ministry of International Trade and Industry Ordinance No. XNUMX) Attached Table XNUMX (related to Article XNUMX) "Time" column Wikisource includesUnit of measure rule #AppendixThere is the original text of.

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