星座の入った風景写真は人気がありますが、星空を描いた絵画というのはそんなに多くないと思います。
しかし、ゴッホの星月夜の絵(図1)は有名で本などで見たことのある人も多いと思います。

この絵はゴッホが精神を病んで療養していた南フランスのサンレミで1889年に描かれています。
これを書く前にゴッホは弟のテオに手紙を書いていて、その中で
「イトスギとともに星空を強く描きたいと思う」と言っています。

図1の左側にイトスギがたち遠景にもイトスギ、そして星の光に呼応するように映し出されるアルプスの山々が見えています。
星の光はエネルギッシュで渦巻く白い光として表され、一つ一つの星や月は白や黄色で周りを囲む後光のように描かれています。
これらは、波や渦のように描かれていますが、一方、
これとは対照的に教会や建物は四角に表現されています。

このころのゴッホは絵をどのように描くかについて非常に不安で、感情が安定しなかったということですが、
その心理がよく現れていると思います。
一方で内に秘めたエネルギーのすごさを感じないわけにはいきません。

ところで、プランクと名付けられた欧州宇宙機関(ESA)が打ち上げた宇宙望遠鏡があります。
この望遠鏡は宇宙の果てからやってくるマイクロ波放射を観測し、
宇宙の始まりの物理状態を調べる望遠鏡です。
マイクロ波の前景の光として私たちの銀河系(天の川)からやってくる光も望遠鏡に入ってきます。
その混入する光の中に、銀河系内のダストからくる放射があります。
この光をうまく取り出し、偏光フィルターを通して撮影すると図2のような映像が撮れました。
誰しもゴッホの絵を想起する画像だったのでびっくりです。

この渦巻く筋は、銀河系内の磁場によってダストが整然と並ぶ効果(細長いダストは磁力線に垂直に並ぶこと)
によって発生します。

自然の美しい画像はこのようなやや抽象的な表現の形にも似るのは不思議なことですね。




画像をクリック（拡大）

図1 The Stary Night, 1889, Vincent van Gogh (提供：Meuseum of Modern Art, New York)
http://astr-www.kj.yamagata-u.ac.jp/~shibata/yamashin/589-fig1.jpg


画像をクリック（拡大）

図2 銀河系ダストからの偏光放射(提供：ESA/プランクチーム)
http://astr-www.kj.yamagata-u.ac.jp/~shibata/yamashin/589-fig2.jpg


本文終わり


references
Van Gogh, by John Cauman, 2019, Pavilon Books Company Ltd 
解説：
In June 1889, while Vincent was a patient at the asylum in Saint-Remy(南フランスのサンレミ),
he paint a nigh landcape with a starry sky, returning to a theme he has explored in Arles in Sept. 1888.
His mental and emotional star had changed drastically over the past year, accompanied by the increasing agitation of
pictorial style(不安感が増していた).

Even before he had created the ealier work, Vincent had told this brother Theo that he was eager
to paint a starry stky with cypresses. シプレ(イトスギ)  

画像をクリック（拡大）

At the left side of the Starry Night, the flame-like forms of cypresses
spiral skyward, with the one at the far left seeming to scale the firmament.
iThe nigh sky teems with cosmic energy: liminous stars of white, yellow and orange, like the waning moon,
are surrounde by circles of light; spricalling swirls are echoed by the undulation of the Alpilles mountain range below.
A church steeple, like the cypress tree soars skyward, but the church itself and other builing of the town
unkek the sky, mountains and threes are stable and block-like. The townn's architecture evokes thatof 
Vincent'a native Netherlands more than thato fo the Provencal twon of Saint=Remy.

The Starry Night is the nocturnal counter part of the Olive Trees; the two works were both painted in June 1889. 
Both present an agitated, turbulent view of nature which reflected the artist's spiritual and emotional crisis at tha time,
but his methods in creating the two works were quite different. The Olive Trees, like Sarry Night over the
Thone of the previou year, was painted en plein air, and based on direct observation, a method that Vincent always
foroured. THe Starry Night, by necessity, was created via a more synthetic precess. Vincent had a magnificent view
of the night sky from the barred windows of his bedroom at the asylum, but the was not permitted to pain from this room,
only to sketc. As a consequence, the starry night has more in common with painting by his Post-Impressionist
colleagues Pau Gaugiun and Rmilie Bernard, whoc workd primarily fomr imagninaatin than wiht those of his
Impressonis forebears.
ゴッホの絵の引用先
提供：Meuseum of Modern Art, New York
絵のタイトル The Stary Night, 1889
作者 Vincent van Gogh
http://www.moma.org.
資料の仕様が認められる場合の記述
https://www.moma.org/about/about-this-site/#terms-of-use

Plank のダストからの変更イメージ
Title Polarised emission from Milky Way dust
Released 05/02/2015 3:00 pm
Copyright ESA and the Planck Collaboration
Description
The interaction between interstellar dust in the Milky Way and the structure of our Galaxy’s magnetic field, as detected by ESA’s Planck satellite over the entire sky.

Planck scanned the sky to detect the most ancient light in the history of the Universe – the cosmic microwave background. It also detected significant foreground emission from diffuse material in our Galaxy which, although a nuisance for cosmological studies, is extremely important for studying the birth of stars and other phenomena in the Milky Way.

Among the foreground sources at the wavelengths probed by Planck is cosmic dust, a minor but crucial component of the interstellar medium that pervades the Galaxy. Mainly gas, it is the raw material for stars to form.

Interstellar clouds of gas and dust are also threaded by the Galaxy’s magnetic field, and dust grains tend to align their longest axis at right angles to the direction of the field. As a result, the light emitted by dust grains is partly ‘polarised’ – it vibrates in a preferred direction – and, as such, could be caught by the polarisation-sensitive detectors on Planck.

Scientists in the Planck collaboration are using the polarised emission of interstellar dust to reconstruct the Galaxy’s magnetic field and study its role in the build-up of structure in the Milky Way, leading to star formation.

In this image, the colour scale represents the total intensity of dust emission, revealing the structure of interstellar clouds in the Milky Way. The texture is based on measurements of the direction of the polarised light emitted by the dust, which in turn indicates the orientation of the magnetic field. 

Id 334841
http://www.esa.int/spaceinimages/Images/2015/02/Polarised_emission_from_Milky_Way_dust