C/1907 L2 (Daniel)
Naked-eye comet discovered by Zaccheus Daniel in 1907.
C/1907 L2 (Daniel), or Daniel's Comet, is a non-periodic comet first spotted by American astronomer Zaccheus Daniel. It was the first of three comets he discovered, and it became visible without a telescope in 1907.
Daniel detected the comet using a 15 cm (5.9 in) comet-seeker on the morning of 10 June 1907, while it was in the constellation Pisces. Its cometary nature was confirmed two days later by William Robert Brooks. The comet brightened quickly as it neared Earth, reaching its closest approach of 0.757 AU (113.2 million km) on 2 August 1907. Edward E. Barnard photographed the comet from 11 July to 8 September 1907, noting it remained visible to the naked eye for two months. Edward C. Pickering also made photographic observations from 12 July to 4 August 1907. On 24 July 1907, J. Charles Duncan recorded the comet at magnitude 3.0. Across the Atlantic, Max Wolf observed the comet extensively until 27 August. The final sighting came from the Chamberlin Observatory in Denver, Colorado, on the early morning of 30 June 1908.
Quick Facts
- Discoverer
- Zaccheus Daniel
- Discovery Site
- Princeton, New Jersey
- Discovery Date
- 10 June 1907
- Designations
- 1907 IV, 1907dICQ1
- Orbit Ref
- jpl
- Epoch
- 27 September 1907 (JD 2417845.5)
- Observation Arc
- 344 days
- Obs
- 173
- Perihelion
- 0.512 AU
- Aphelion
- 830.60 AU
- Semimajor
- 415.55 AU
- Period
- ~8,470 years (inbound) / ~5,220 years (outbound)
Facts from the source article.
Lore & Background
The comet was discovered by Zaccheus Daniel using a 15 cm (5.9 in) comet-seeker on the dawn of 10 June 1907, though its nature as a comet was not confirmed until two days later by William Robert Brooks. At the time, the object was located within the constellation Pisces. The comet rapidly brightened as it slowly approached Earth, reaching its closest point at 0.757 AU (113.2 million km) on 2 August 1907. Edward E. Barnard made a series of photographic observations of the comet between 11 July and 8 September 1907, describing it as visible to the naked eye for two months. Edward C. Pickering also made several photographic observations between 12 July and 4 August 1907. J. Charles Duncan noted that the comet had reached magnitude 3.0 on 24 July 1907. Across the Atlantic, Max Wolf made extensive observations of the comet until 27 August. It was last observed from the Chamberlin Observatory in Denver, Colorado, on the early morning of 30 June 1908.
Reader's Guide
C/1907 L2 (Daniel) holds significance as the first of three comets discovered by American astronomer Zaccheus Daniel, and as a notable naked-eye comet of 1907. Its discovery and confirmation involved two astronomers—Daniel and William Robert Brooks—highlighting the collaborative nature of early 20th-century comet hunting. The comet's rapid brightening and close approach to Earth at 0.757 AU allowed extensive photographic documentation by prominent astronomers such as Edward E. Barnard, Edward C. Pickering, and Max Wolf, providing a rich observational record. The comet's peak magnitude of 3.0, recorded by J. Charles Duncan, made it easily visible without optical aid for about two months. Its last observation from the Chamberlin Observatory in Denver, Colorado, in June 1908 marked the end of its visibility. As a non-periodic comet, it will not return, making the historical observations a permanent record of its single passage through the inner solar system.
Did You Know?
- Its nature as a comet was confirmed two days after discovery by William Robert Brooks.
- Edward E. Barnard made photographic observations of the comet from 11 July to 8 September 1907.
More in Named Comets, Part 4 1-24
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