Editing Halley's Comet (section)

===1835===
At [[Markree Observatory]] in Ireland, [[Edward Joshua Cooper]] used a [[Robert-Aglaé Cauchoix|Cauchoix of Paris]] lens telescope with an aperture of {{convert|13.3|inch|mm|order=flip}} to sketch Halley's comet in 1835.<ref name="Abrahams2009"/> The same apparition was sketched by German astronomer [[Friedrich Wilhelm Bessel]].<ref name="Smithsonian1835"/> Observations of streams of vapour prompted Bessel to propose that the [[jet force]]s of evaporating material could be great enough to significantly alter a comet's orbit.{{sfn|Sagan|Druyan|1985|p=117}}

{{multiple image
|align=right
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|header=Illustrations of prior comet appearances in the January 1910 ''[[Popular Science|Popular Science Monthly]]'' magazine
|image1=PSM V76 D017 Halley comet in 1682 (horizontal).png
|caption1=1682
|image2=PSM V76 D017 Halley comet in 1759 (horizontal).png
|caption2=1759
|image3=PSM V76 D018 Halley comet in 1835.png
|caption3=1835
}}
An interview in 1910, of someone who was a teenager at the time of the 1835 apparition had this to say:<ref name="Todd Saw Halley's Comet in 1835"/>

{{blockquote|When the comet was first seen, it appeared in the western sky, its head toward the north and tail towards the south, about horizontal and considerably above the horizon and quite a distance south of the Sun. It could be plainly seen directly after sunset every day, and was visible for a long time, perhaps a month ...}}

They go on to describe the comet's tail as being more broad and not as long as the comet of 1843 they had also witnessed.<ref name="Todd Saw Halley's Comet in 1835"/>

Famous astronomers across the world made observations starting August 1835, including Struve at Dorpat observatory, and Sir John Herschel, who made of observations from the Cape of Good Hope.<ref name=":0"/> In the United States telescopic observations were made from [[Yale College]].<ref name=":0"/> The new observations helped confirm early appearances of this comet including its 1456 and 1378 apparitions.<ref name=":0"/>

At Yale College in Connecticut, the comet was first reported on 31 August 1835 by astronomers D. Olmstead and E. Loomis.<ref name=":2"/> In Canada reports were made from Newfoundland and also Quebec.<ref name=":2"/> Reports came in from all over by later 1835, and often reported in newspapers of this time in Canada.<ref name=":2"/>

Several accounts of the 1835 apparition were made by observers who survived until the 1910 return, where increased interest in the comet led to their being interviewed.<ref name=":2"/>

The time to Halley's return in 1910 would be only 74.42 years, one of the shortest known periods of its return, which is calculated to be as long as 79 years owing to the effects of the planets.<ref name="NASA_1P-explore"/>

At [[Paris Observatory]] Halley's Comet 1835 apparition was observed with a Lerebours telescope of {{convert|24.4|cm|in|abbr=on}} aperture by the astronomer [[François Arago]].{{sfn|Lequeux|2015|p=180}} Arago recorded polarimetric observations of Halley, and suggested that the tail might be sunlight reflecting off a sparsely distributed material; he had earlier made similar observations of [[Comet Tralles]] of 1819.<ref name="Levasseur-Regourd2019"/>