Ihle was born on June 14, 1627 in Germany, possibly in Leipzig. He worked in Leipzig as a post-office official. As an amateur astronomer Ihle observed sunspots (1680-1687), planets and comets. He was a friend of Kirch and Hevelius. Ihle and Kirch were in close contact (letters, visits in Berlin) about their observations. Ihle made observations till 1695 and died probably in 1699 or a little later in Leipzig.
Ihle probably found NGC 6652 = M 22 on August 26, 1665 while observing Saturn in Sagittarius with a small refractor ("composite nebula between the head and the bow of the archer onto which a great number of faint stars was projected"). This is published in: Kirch, G., Ephemeridum Motuum Coelestium Ad Annum Aerae Christianae 1682. Cum Appendice Observationum Nonnullarum Astronomicarum, Leipzig 1682 (cited by Schultz, AN [1585] 67, 1 (1866)). That Ihle discovered M 22 is also the common opinion of Halley, de Chesesaux and Messier. It is interesting that Saturn made a triple conjunction with M 22 in 1665 (the year before aphelion). Hevelius may have seen M 22 a little earlier, according to Kirch. Admiral Smyth notes, that perhaps Abraham Hill, 1st coucil of the Royal Society, is the real "Ihle", but this not accepted.
D | N | NI | Y | M | D | I | T | Observer | Name | Con | Type | S |
1 | N | 6656 | 1665 | 8 | 26 | Rr | v | Halley 1715 Lacaille 6.4.1752 |
M 22 | SGR | VII | 5 |