Welcome to CometWatch! Your Hosts are Nick Evetts, Neil Norman & Mary Spicer.
This Month we are joined by Terry Lovejoy, Justin Tilbrook & Michael Mattiazzo and we discuss The History of Comet Hunting
The Notes Used for the Show
Discoverer of 13 comets with only a basic telescope that had a mirror made with speculum (glass wasn’t used until the 1850’s), and an aperture of 5 inches.
He became interested in comets after seeing the Great Comet of 1744 ( C/1743 X1).
During his career he observed 44 of the possible 50 comets to appear between 1758-1806.
Also discovered 13 comets and became interested in comets after seeing the Great Comet of 1843.
In 1857 he obtained some astronomy books, and with the instructions in one of them, he made a 3 inch scope. The mirror was accidentally broken , so he brought a 4 inch “Comet Seeker ” telescope.
His most notable discovery was 109P/ Swift-Tuttle , the parent of the Perseid meteor shower.
Edward Emerson Barnard.
Discovered his first comet in 1881, yet failed to report it!
He purchased a 5 inch telescope in 1876 , and went on to discover 16 comets in total.
In 1892 he discovered D/1892 T1, the first to be discovered photographically.
William Robert Brooks.
Was nicknamed “Eagle Eyes”, a name well deserved with 27 comet discoveries.
He was born in England but moved to the U.S in 1857.
Founded the Red House Observatory,Phelps,N.Y, 1874, where he discovered 11 comets.
He went on to discover another 16 comets (mostly with his 5 inch telescope).
The most successful visual comet discoverer of all time with 37 finds.
This said, he was a terrible note keeper, and his tally could have been around 44 had he have kept an up-to-date log book.
He used telescopes of his own design, his “Grand Chercheur” ( “Great Seeker”) had an aperture of 5 inches.
The Evolution of Comet Hunting: Past, Present and Future
Rob McNaught (82) – Siding Spring Survey. (101 total )
– launched in late 1995 (L1 lagrangian point between Sun and Earth)
– is the most effective comet hunter on record, as of September 2016 – 3168 discoveries!
– Majority of these comets are discovered by amateurs trawling data over the internet
– if you want to have a go at finding a SOHO comet,
Recommend Karl Battams Sungrazer project website
– search and download SOHO near realtime data from their website. (very competitive)
– LASCO C3 field of view is about 8 degrees radius around the Sun,
– LASCO C2 field of view about 2 degrees
– use highest resolution images at 1024×1024.
– Most of the comets discovered by SOHO are members of the Kreutz sungrazing family (fragments of)
– Extremely faint, unobservable from the Earth, don’t survive perihelion
– Other groups have been discovered: Meyer, Marsden, Kracht groups.
– Secret behind SOHO’s success – Comets are brightest when closest to the Sun (r^4)
– Solar Wind Anisotropy camera on board SOHO.
– looks away from the Sun.
– Nearly the entire sky in Ultraviolet using the hydrogen lyman alpha emission.
– low resolution camera (1 degree)
– very effective comet hunter because comets generate massive comae when approaching the Sun due to disassociation of water into Hydrogen.
– Coma size can easily reach over 1 million kms for the larger comets.
– You can discover comets by downloading comet tracker maps from their website.
- SWAN is capable of detecting comets as faint as 12th magnitude.
- Very challenging to find new objects due to high amount of background sources
- Any possible candidates are followed up by ground based confirmation using backyard camera on tripod setup.
- I can get approximate positions down to a few degrees.
– Funding until end of 2016?
STEREO A and B spacecraft.
- Launched in 2006 in orbits around the Sun that caused A to pull further ahead and B to fall gradually behind the Earth in its orbit.
- A (ahead) passed through solar inferior conjunction in 2014. Now receiving data. (Ahead spacecraft is now “behind” the Earth and will catch up by 2023)
- B (behind) lost contact prior to solar conjunction (overheating)
- ?10 comets discovered by amateurs trawling through data.
You can discover comets by downloading heleospheric images from their website.
HI1-A images show the region of sky from about 8 degrees solar elongation to 25 degrees.
HI2-A images are widefield, showing large regions of sky and only good for viewing comets near the spacecraft.
HI STARS A
New Borisov comet poorly situated for Earth observers, but due for a close approach to Stereo A in late October.
PANSTARRS (138 and rapidly rising)
Panoramic Survey Telescope and rapid response system
- 8m telescope located at Haleakala in Hawaii (Maui)
- 3 degree FOV
- 4 giga pixel camera
- 1 minute exposures can record stars down to magnitude 22
- All sky coverage over 4 nights
Large Synoptic Survey Telescope LSST
- Currently under construction in Chile (Cerro Pachon)
- Commence operations in 2022
- 8 meter primary mirror.
- Photograph entire visible sky over 3 nights
- 6 square degree fov. 3 mirror design
- 2 gigapixel camera, largest digital camera ever constructed – size of a small car!
- 15 second exposures
- Accumulate 30 terabytes of data per night. 1.28 ppetabytes of data per year
- Rapid response system – may be a great time for amateurs to follow up discoveries!
- 10 year lifetime
Female Comet Hunters
Sophia Brahe (1556-1643)
- Assisted her husband Tycho Brahe in his observations, including of comets
Maria Margarethe Kirch (Maiden name Winkelmann) 1670 – 1720
- Born in Germany
- Educated as a child by her father, before studying with self-taught astronomer Christoph Arnold. She became his unofficial apprentice then formally his assistant, during which time she lived with him and his family. Through him she met fellow astronomer and mathematician Gottfried Kirch. He was 30 years older than her but they married and 4 children, all of whom went on to become astronomers
- Maria and Gottfried worked as a team and through observations and calculations, they produced calendars and ephemerides.
- On 21st April 1702 she discovered the “Comet of 1702” C/1702 H1, making her the 1st woman to discover a comet (although Caroline Herschel is often credited as the first). However, Gottfried took the credit for this discovery. It may have been because of fear of ridicule, or it may be because Maria wasn’t able to speak or write Latin, which was the language of the journal that reported these findings. They admitted the truth in 1710 but the comet was never named after her
- Funded by a family friend, she continued working as an astronomer with her children as assistants, and had much of her work published in German scientific publications. When her husband died she wanted to continue with their business but the Royal Academy of Sciences refused to grant her membership. However, the Berlin Academy of Science did admit her and she continued to work
Maria Kirch. Photo source: http://thelifeofmariawinkelmann.weebly.com/introduction.html
- Gabrielle Emilie, Marquise du Châtelet (1709-1749)
- Made a commented translation into French of Newton’s Principia, which deals among other things with the orbit of comets
Gabrielle Emilie (Source: http://cometes.obspm.fr/en/the-forgotten-story-of-female-comet-finders )
Nicole-Reine Lepaute (1723-1788)
- Wife of the watchmaker to the French King, Jean-André Lepaute. According to Lalande she was the most illustrious of French female astronomers.
- She predicted the return of Halley’s comet in 1759, and included the effect that the force of gravity caused by the planets would have on the path of the comet
Caroline Lucretia Herschel – 1750 – 1848
- Born in Germany. Her growth was stunted due to contracting typhus at a young age. Her parents thought she would never marry and had her working as a servant/scullery maid at home. In 1772 her brother William called her to London and she to have music lessons with him. Together they had a very successful music career but astronomy began to take over their lives. William taught her maths and astronomy and she became his assistant, helping with observations, recording data, polishing mirrors and mounting telescopes. Together they installed an observatory in Slough.
- Using a small telescope which William built for her she discovered 8 comets and several nebulae. Her first discovery was M110, in 1783. In 1787 the King gave her an annual pension to work as William’s assistant, and so became the first woman in history to be paid for scientific work. She also became the first woman to be elected into the Royal Astronomical Society. In 1791 she began to use a new 9” telescope for comet hunting
- Cometary discoveries:
-C/1786 P1 (Herschel) – discovered 1st Aug 1786
-35P/Herschel-Rigollet – discovered by Caroline in 21st Dec 1788, then 15 years later by Rigollet
-C/1790 A1 (Herschel) – discovered 7th Jan 1790
-C/1790 H1 (Herschel) – discovered 17th April 1790
-C/1791 X1 (Herschel) – discovered 15th Dec 1791
-C/1793 S2 (Messier) – she spotted it 7th Oct 1793 but Messier had spotted it 1st on 24th Sept
-2P/Encke – sighted by Caroline on 7th Nov 1795. However, it had previously been discovered by Pierre Mechain in 1786 who notified Messier & Cassini who all observed it 2 days later. But it slipped into twilight before they could do any orbit calculations. Caroline spotted it again in 1795, when it was visible for 3 weeks but still there wasn’t enough data to get accurate calculations. It was discovered again in 1805 by Pons, Huth & Bouvard, however, it was Encke who studied all the previous data and did the calculations that confirmed that all of these sightings were the same comet, which had a 3.3 year period. he went on to correctly predict its return
-C/1797 P1 (Bouvard-Herschel) – discovered on 14th Aug 1797, both Eugene Bouvard & Caroline discovered it within a few hours of each other
- Caroline Herschel set a record for comet discoveries by a female astronomer which wasn’t broken until the 1980s, by Carolyn Shoemaker. She also created a brand new sky catalogue “Catalogue of Nebulae & Clusters of Stars” to replace the erroneous one done by John Flamestead
Caroline Herschel and her telescope (Wikiepdia)
Maria Mitchell – 1818 – 1889
- Born in Massachusetts, she was born into a community who favoured in equality for women so she received the same level of education as the boys. When she was 11, her father built his own school where she studied and also worked as a teaching assistant to her father. He taught her astronomy at home using his own telescope. In 1835 she opened her own school.
- Using a telescope, on 1st Oct 1847 she discovered “Miss Mitchell’s Comet” C/1847 T1) and was awarded a gold medal prize from King Frederick VI of Denmark. This gave her worldwide fame as she was only the 3rd female astronomer to discover a comet
- She became the first woman elected Fellow of the American Academy of Arts and Sciences and of the American Association for the Advancement of Science. She was also one of the first women elected to the American Philosophical Society. She became professor of astronomy at Vassar College in & was also named as Director of the Vassar College Observatory
Maria Mitchell (source: Wikipedia)
Dorothea Klumpke (1861-1942)
Married to the wealthy Welsh astronomer Isaac Roberts, she made observations of comets, among others
Carolyn Jean Shoemaker (maiden name Spellman) – 1929 – present
- Born in Mexico but grew up in California. In her early career she was a teacher. She married Gene Shoemaker in 1951 and she then left work to raise her family.
- In 1980, at aged 51, she began her astronomy career by searching for Earth-crossing asteroids and comets at the California Institute for Technology and Palomar Observatory. She used the stereo machine which her husband had co-created in order to find these objects. The machine allowed her to study 2 images of the sky taken 45 minutes apart, to look for objects that are moving relative to the background stars. She worked very closely with her husband and fellow comet hunter David Levy, until the death of her husband following a car crash in 1997. After that she continued to work at the Lowell observatory with David Levy and still works there today. During her career to date, she has discovered over 900 asteroids and 32 comets, the most famous being Comet Shoemaker-Levy 9, which impacted Jupiter in 1992
Carolyn Shoemaker (Source: Wikipedia)
“The Unforgotten Sisters: Female Astronomers & Scientists Before Caroline Herschel” by Garbriella Bernardi
The ladies who actually discovered comets were Maria Margareth Kirch 1670 – 1720 Caroline Herschel 1750 – 1848 Maria Mitchell 1818 – 1889 Carolyn Shoemaker 1929 – present
Ladies who observed and contributed to observations & calculations were: Sophia Brahe 1556 – 1643 Gabrielle Emilie 1709 – 1749 Nicole-Reine Lepaute 1723 – 1788 Dorothea Klumpke 1861 – 1942
I guess we’ll never know just how many ladies observed and contributed in secret, hiding behind their husband’s name