Ejnar Hertzsprung (October 8, 1873, Copenhagen – October 21, 1967, Roskilde) was a Danish chemist and astronomer.

In the period 1911-1913 with Henry Norris Russell, he developed the Hertzsprung-Russell diagram.

In 1913 he determined the distances to several Galactic Cepheid stars by statistical parallax, and was thus able to calibrate the relationship discovered by Henrietta Leavitt between Cepheid period and luminosity. In this determination he made a mistake, possibly a slip of the pen, putting the stars 10 times too close. He used this relationship to estimate the distance to the Small Magellanic Cloud.

He discovered two asteroids, one of which is the Amor asteroid 1627 Ivar.

Honors

• Gold Medal of the Royal Astronomical Society in 1929
• Bruce Medal in 1937.

Named for him

• Hertzsprung crater on the Moon.
• Asteroid 1693 Hertzsprung.

External links

• Bruce Medal page
• Awarding of Bruce Medal: PASP 49 (1937) 65
• Awarding of RAS gold medal: MNRAS 89 (1929) 404

Obituaries

• AN 290 (1968) 287 (one line, in German)
• AN 291 (1969) 85 (in German)
• JRASC 62 (1968) 137
• Obs 87 (1967) 298 (one line)
• PASP 79 (1967) 638 (one line)
• PASP 80 (1968) 51
• QJRAS 9 (1968) 337

1873 births | 1967 deaths | Danish astronomers | Danish chemists | Asteroid discoverers

Ejnar Hertzsprung | Ejnar Hertzsprung | Ejnar Hertzsprung | Ejnar Hertzsprung | Ejnar Hertzsprung | アイナー・ヘルツシュプルング | Ejnar Hertzsprung | Ejnar Hertzsprung | Ejnar Hertzsprung | Ejnar Hertzsprung | Ejnar Hertzsprung | 赫茨普龍