Public astronomical observatories in Japan－27－

Public astronomical observatories in Japan～Current status, challenges and potential～
Koki Sawada (JSPS Research Fellowship for Young Scientists / Wakayama
Univ.), Tatsuki Yonezawa (Misato Astronomical Observatory / Wakayama
Univ.), The research committee of Japan Public Observatories Society
本 稿 は 、 2023 年 に 日 本 公 開 天 文 台 協 会

the purpose of academic research.

（ JAPOS ） が 発 行 し た 『 公 開 天 文 台 白 書

A distinctive feature of the Japanese2018 』 1 ） の 概 要 を 英 訳 し た も の で あ る 。

PAOs is that many are equipped with

『公開天文台白書 2018』は、198 の施設状

large-aperture telescopes [3]. Since the況をとりまとめた報告書で、わが国におけ

1980s, telescopes with apertures larger

る公開天文台の現状を様々な角度から把捉

than

2）

60

cm

have

been

successively。「天文台王国」の様相

installed [4], including 14 PAOs with3 ）、

apertures larger than 100 cm since 1990

国際的に発信することを企図して、その概(Table. 1.). Currently, at least 300 PAOs

要を英文で報告することとした。また近日

are in Japan, including smaller facilities

中に、同様の調査を実施する予定である。

[5].

することができるを呈するわが国の公開天文台の現状を

関係施設の皆様からの引き続きのご協力・

However, PAOs have faced challenges

ご助言を頂けると幸いである [JAPOS 調査

due to secular changes in the local

研究委員会]。

governments’ socioeconomic environment,
as operating entities are unable to raise

1. Introduction

funds to maintain their instruments andAstronomy has made a significant

operate their facilities, forcing them topublicoperate with limited staff. In recent years,

interest in astrophysics and the universe.

some observatories have been forced toFurther, astronomical observatories haveclose down (Table.1.).

contribution

tostimulating

served not only as academic researchfacilities
connecting

but

also

as

amateurandThis report presents the results of an

institutions

extensive

surveyofJapanese

PAOs

academic

conducted

by

the

Japan

Publicastronomers and as practical facilities for

Observatory Society in 2018. The results

the general popularisation of astronomy

were documented in “ The White Paper of[1][2].

observatories

PAO in 2018 ” (in Japanese). This report

established primarily for the purpose of

aimed to provide information on theserving the public are referred to as

current status, operational challenges,‘public astronomical observatories’ ( kōkai

and potential of Japanese PAOs.

In

tenmondai ;Japan,

thePAO)',

whicharedistinguished from those established for
天文教育 2024 年 7 月号（Vol.36 No.4）

－28－

■ 投

稿 ■

refer to telescopes equipped with mobile
Table.1. Japanese PAOs with telescopes withastronomical vehicles (e.g. ASTROCAR)

apertures larger than 100 cm

or trolleys. Therefore, science centres andObservatory Name
Nishi-Harima
Astronomical
Observatory
NayoroObservatory
KITASUBARU
Gunma
Astronomical
Observatory
SendaiAstronomical
Observatory
Rikubetsu Spaceand Earth Science
MuseumAnan Science
CenterIshigakijima
Astronomical
Observatory
MisatoAstronomical
Observatory
Tottori Saji
AstroParkThe Yamazaki
Observatory
Bisei Astronomical
Observatory
Hoshi noBunkakan
ToyamaAstronomical
Observatory(closed)Kawabe Cosmic
Park (closed)

Aperture
(cm)

Since
(year)

200

2004

museums with assembled telescopes forstar parties were excluded from thesurvey.

Universities

andacademic

institutions primarily used for research
160

2010

purposes were also excluded.
The questionnaire consisted of twoparts.

150

1999

The

first

part

includedbasic

information about the facility, such as its
year of establishment, opening hours,

130

2008

participation

fees

for

night

sky

observations (NSO), and the installation
115

1998

113

1999

105

2006

status of the surrounding accommodation
facilities. The second part consisted of theoperational status of the facility, such as
the type of operating entity, number ofstaff members, operational budget, andnumber of participants in the NSO.

105

1995

103

1994

101

1994

101

1993

100

2017

This survey was distributed to 360
PAOs who met these criteria. The survey
was conducted via the web and mail. A
total of 198 facilities completed thesurvey (response rate of 55 %).
3. Results
3.1

Location and the size of telescope

aperture
100

1997

100

1996

PAOs were installed throughout Japan,
but the number in northern Japan tended
to be relatively smaller. In addition, thewestern part of Japan had telescopes withapertures that tended to be larger thanthose in the eastern part of Japan (Fig.1.).

2. Method
In this study, a PAO is defined as ‘aThis may be related to the fact that thefacility with fixed ground-based optical

weather is more stable in the westerntelescopes or mobile telescopes open topart of Japan (e.g., a greater number ofthe general public’. Mobile telescopes
天文教育 2024 年 7 月号（Vol.36 No.4）

Public astronomical observatories in Japan－29－

Fig.1. The PAOs distribution map by telescope aperture size (n=198)
established by local governments, while

sunny days).
The ‘20 cm–39 cm’ and ‘40 cm–59 cm’

the remaining 20% were established byclasses were the most dominant telescope

private companies or corporate organisations,apertures,

such

with

telescope

apertures

as

the

third

sector(e.g.

larger than 60 cm in approximately aquarter of the total (Fig.2.). In terms of
installation rates by telescope type, 33%
of telescopes were refracting telescopes
and 66% were reflector telescopes.
3.2

Establishing and operating entities

PAOs were most commonly establishedby cities or wards, accounting for 61% of
the total population (Fig. 3, [6]), followedby the prefectures (11%) and towns (9%).

Fig.2. Percentage of main telescope ap-

Therefore,

ertures installed in PAOs (n=189)

approximately

80%

were

天文教育 2024 年 7 月号（Vol.36 No.4）

an

－30－

Fig.3.

Establishment

entities

of

■ 投

稿 ■

PAOs

Fig.4. Present operating entities of PAOs
(n=195)(n=195)independent administrative institution).
Although cities and wards represented
the largest operating entities, accounting
for

35%,

their

share

has

decreased

services. We found 35% of PAOs had
already

adopted

DAS,

and

7%

were

considering introducing the system.
Both advantages and disadvantages

compared to when they were established(for(Fig.4.). Fig.4 shows that 48% PAOs are

However, emphasising short-term costcurrently operated by local governments.

savings and management efficiency may

Conversely, the proportion run by private

lead to the devaluation of PAOs, which

companies or corporate organaisations

are less likely to generate direct economic

has increased compared to the time they

benefits. The effects of DAS must bewere

carefully

established.

Therefore,

PAOs

established by local governments were

example,[7])

examined

existed

from

a

in

DAS.

range

of

perspectives.

likely taken over and run by these
3.3

organisations.
This feature seems to be related to theEquipment

Fig.5 shows the percentage of each typeofof observation equipment, illustratingthethat digital cameras (with replaceable

adoption of the Designated Administrator

lenses) and video cameras were owned by

System (DAS) since 2003. DAS is amore than half the PAOs.

deteriorating

financial

Japan’s

governments

localmanagement

systemsituation
andwherebypublicfacilities (e.g. museums, cultural centres)
previously operated by local governments
are given to private companies, NPOs,
and corporate organisations to manage on
their behalf, allowing public facilities toutilise their expertise to improve the
天文教育 2024 年 7 月号（Vol.36 No.4）

Public astronomical observatories in Japan－31－

Fig.5. the percentage of each type of observation equipment owned PAOs(n=146)
Planetariums were present in 47% ofRegarding wheelchair accessibility in

PAOs. In particular, larger institutions,the observatories, 12% of PAOs allowed

such as museums and science centres,

those in wheelchairs to visit freely, 41%tended to have this type of equipment.

could visit in their caregivers, and 47%

Further, 38% of PAOs owned solar tele-

could not visit. These results suggest that

scopes. Of these, 21% responded that theyJapanese PAOs are not sufficiently bar-used solar telescopes to project or display

rier-free—for example, the lack of lifts orimages of the sun to visitors.

ramps in the facilities.

Fig.6. The histogram of NSO participants in 2017 (n=163)
天文教育 2024 年 7 月号（Vol.36 No.4）

－32－

■ 投

稿 ■

participants was 363,065. In terms of frequency, the largest proportion had fewer
than 500 visitors in 2017 (56%), followedby 1,000–2,000 and 500–1,000 visitors(Fig.6.). Some NSOs had more than
15,000 participants, particularly thosewith an observatory along with their accommodations.
The most frequent NSOs was ‘once or
twice a month’ (26%), followed by ‘lessFig.7. NSO frequency (n=160)

than once a month’, and ‘twice or third amonth’ (Fig.7.). However, 10% of all facilities held NSOs more than five times a
week.
In terms of participation fees, 56% of
the facilities were free of charge. The average cost to visit the fee-paying facilities
was JPY 367. Thus, most observatories inJapan charge less than JPY 1,000 to participate in NSOs operations.
Regarding changes in the number of
NSO visitors over the past five years, 31%

Fig.8. The demographic of NSO partici-

of facilities reported an ‘increased’ num-

pants (n=189)

ber of visitors, 55% ‘remained stable’, and
12% ‘decreased’. The most commonly selected demographic for NSO visitors was‘family’(48%),

followedby‘seniors’(Fig.8.).
In terms of accommodations, 24% of the
PAOs had accommodations, 26% had accommodations close to the observatory,
and 46% had no accommodation facilities.
The proportion of local users visiting facilities was highest at ‘0%–10%’, followed
Fig.9. The histogram of proportion of local

by ‘81–90%’ (Fig.9.). Although the charac-

users overall (n=166)

teristics of visitors varied depending on
the PAOs, as facilities with fewer local

3.4

NSO for the public

residents (i.e. more tourists from otherIn 2017, the total number of NSO

areas)

tended

天文教育 2024 年 7 月号（Vol.36 No.4）

tobeequippedwithPublic astronomical observatories in Japanaccommodations.

－33－

DAS, showing that non-permanent employees are responsible for operating

3.5

Staff

more than half of the Japanese PAOs fa-

The most frequent number of employ-

cilities.

ees in the PAOs was ‘2–5’ full-time staff(31%), followed by ‘6–10’ and ‘0–1’ full-

3.6

Budgettime staff (Fig.10.). Full-time staff tends

In terms of annual operating costs, ex-to be more prevalent in larger institu-

cluding personnel and utilities, moretions, such as museums and science cen-than 70% of the facilities reported annual

tres.

operating costs of less than JPY 2 million

The most common employment statusof the staff was full-time public servants(Fig.12.). No annual operating costs wereincurred for any of these facilities.

(25%), followed by contracted staff andRegarding equipment maintenance andpermanent employees of private compa-

operating costs, 65% of facilities reported

nies (Fig.11.). The high proportion of con-budgeting for them annually (Fig.13.).

tracted staff seems to be related to theFig.12. Annual operating budgets excluding
Fig.10. The number of full-time staffs

personnel and utilities (n=180)(n=188)

Fig.11. The employment status of PAOs’

Fig.13. The status of equipment & man-staff (n=182)

agement budget (n=192)
天文教育 2024 年 7 月号（Vol.36 No.4）

－34－

■ 投

稿 ■

However, 6% of facilities reported thatgeneral public (c.f., [8]). One feature ofthey had not budgeted for these costs.

Japanese PAOs is the relatively low cost

Such facilities may become inoperable ifof participation fee and accessibility totheir observational equipment is broken

the general public.

down.

However, PAOs are currently forced tooperate with low budgets and limited

3.7

Effort distribution

staff to make ends meet. Facilities that do

Fig.14 shows the responses regarding

notconsider

the

risk

of

equipment

the top three important factors in the ex-

maintenance costs find sustainable oper-

ternal evaluation of facilities. The mostation difficult. The introduction of DAS

frequent response was ‘lifelong training /has led to confusion among staff at facili-

school education’ (39%), followed by ‘theties where the operating entity changes

number of visitors to the facility’ (38%).

regularly. PAOs are expected to provide‘Academic research’ accounted for only 3%social education facilities, including life-of the research.

long training and school education, as

The demands for ‘lifelong training /well as tourist attractions, offering highschool education’ and ‘the number of visi-

satisfaction to visitors. Future opera-

tors to the facility’ indicated that Japa-

tional challenges are related to the ability

nese PAOs should fulfil both their role asof PAOs to provide such diverse roles withsocial education facilities and tourism re-limited management resources.
Japanese PAOs face challenging oper-

sources.

ating conditions, but the staff are
by no means pessimistic about
running

theirfacilities.

Some

PAOs organise astronomy courses
for the general public and practice astronomical observations incooperation with amateur astronomers(e.g.,

[9]).

More

im-

portantly, observatories are valuable local resources. Therefore,
creating a system in which obFig.14. Effort distribution of PAOs (n=187)

servatories can be managed incollaboration with local residents are nec-

4. Summary

essary.

Despite its small size of national land,
Japan has many PAOs. Japanese PAOs註

have played a role in providing opportu-

1）日本公開天文台協会調査研究委員会編

nities for astronomy experiences to the（2023）『公開天文台白書 2018』，日本公天文教育 2024 年 7 月号（Vol.36 No.4）

Public astronomical observatories in Japan－35－

開天文台協会．https://www.koukaitenm

https://www.koukaitenmon-

ondai.jp/whitepaper/2018/whitepaper2

dai.jp/setumei/setumei.html[6] An overview of Japanese local govern-

018.pdf
2）米澤樹・澤田幸輝・日本公開天文台協会

ment system can be referred to below.

調査研究委員会（2024）「公開天文台白書

Council of Local Authorities for Inter-2018 の完成報告」，日本公開天文台協会第national Relations (2022). Local Gov-

17 回大会集録，77-79．

ernment in Japan 2020 (2022 Revised3）南阿蘇ルナ天文台編（2024）『博物館としての公開天文台』，日本公開天文台協会
第 9 回全国研修会テキスト. https://www.

Edition) ,https://www.clair.or.jp/j/fo-

rum/pub/docs/jichi2022-en.pdf[7] Imanishi, J., & Nakamura, R. (2019).

koukaitenmondai.jp/kenshukai/tokyo2‘Effectiveness

024/tokyo2024.pdf

Designatedanddisadvantages

Administration

in

of

City

Parks through Joint Ventures’, InternaReferences

tional review for spatial planning and[1] Ayani, K. et al., (2002). ‘Educationalsustainable development, 7 (1), 4-17.

activities of Bisei Astronomical Obser-[8] Takanashi, N. et al. (2024). ‘Survey ofvatory as an example of cooperation be-

public attitudes toward astronomy intween public observatories and local

Japan’. Publications of the Astronomi-

schools’. The proceedings of the IAU

cal Society of Japan, 76 (1), 108-117.

8th Asian-Pacific Regional Meeting , 93-[9] Kuroda, T., & Tsumuraya, F. (2003).

94.

‘Development, Construction and Plans[2] Kogure, T. (2004). ‘The role of public

for Small Telescopes in Japan’. Oswalt,

observatories in astronomical observa-

T, D. (Eds). The Future of Small Tele-

tions’. Wamsteker, W. (Eds.). Develop-

scopes in the New Millennium. (pp.

ing Basic Space Science World-Wide.

147-165). Kluwer Academic Publishers.

(pp. 293-298). Springer.
[3] Kuroda, T., & Tomita, K. (1996). ‘Present status of the optical telescope withsmall-to-medium size in Japan’. Kaifu,
N. (Eds.). Ground-based astronomy in

Asia . (pp. 62-66). National Astronomical Observatory Japan.
[4] Kuroda, T. (1993). ‘Present status of
the public observatories in Japan’, An-nual Report of the Nishi-Harima Astro-

澤田

nomical Observatory, 3 , 46-56.

Koki Sawada[5] Japan Public Observatory Society(n.d.). Establishment of the Japan Public Observatory Society (in Japanese),
天文教育 2024 年 7 月号（Vol.36 No.4）

幸輝