John Herschel Made Four Observations of Lenticular Galaxy NGC 7302

Summary: John Herschel made four observations of lenticular galaxy NGC 7302, which his father, Uranus discoverer William Herschel, discovered Oct. 3, 1785.

Sir William Herschel’s 20-foot reflecting telescope, through which Sir William discovered NGC 7302 on Oct. 3, 1785, and used for his son’s four observations of NGC 7302: W. Herschel, W. Bunce and J. Walker’s William Herschel’s Twenty-Foot Reflecting Telescope (1794 print), CC BY 4.0 International, via University of Cambridge Institute of Astronomy Library

John Herschel made four observations of lenticular galaxy NGC 7302, which was discovered Oct. 3, 1785, by his father, Uranus discoverer William Herschel.

German-British astronomer and composer Sir William Herschel (Nov. 15, 1738-Aug. 25, 1822) discovered NGC 7302 on Oct. 3, 1785, four years six-plus months after his March 13, 1781, discovery of solar system planet number seven, Uranus. His discovery of NGC 7302 appears as entry IV-31 in his Catalogue of a Second Thousand of New Nebulae and Clusters of Stars, published in 1789.

Sir William made his discovery of the lenticular galaxy in Aquarius the Water Bearer constellation with his 18.7-inch aperture, 20-foot reflector telescope. Sir John used his father’s telescope for his four observations of NGC 7302.

Sir William’s only child, John Frederick William Herschel, 1 Baronet (March 7, 1792-May 11, 1871), made his first observation of NGC 7302 during Sweep 37 of deep-sky objects, conducted Aug. 5, 1826. His second and third observations happened on two successive dates in July 1830. Sweep 273 and Sweep 274 occurred, respectively, on July 26 and July 27. Sir John’s fourth observation took place Sept. 10, 1831, during Sweep 373.

Sir John compiled his four observations under entry number 2165 in his astronomical catalogue, Observations of Nebulae and Clusters of Stars, Made at Slough, which was published in 1833. His observations are arranged in order of right ascension, the celestial equivalent of terrestrial longitude. Accordingly, his observation from Sweep 273 (July 26, 1830), which occurred chronologically as the second of the four observations, appears first.

The Sweep 273 observation has equatorial coordinates of right ascension at 22 hours 23 minutes 15.6 seconds and declination at 104 degrees 59 minutes 37 seconds. He remarks: “F; pL; R; v s b M to a S, F, R nucleus; diam 2’; has a * s f in pos 352°.5 by micr; dist 3’.”

Sir John’s description transcribes as: “Faint; pretty large; round; very suddenly bright in the middle to a small, faint, round nucleus; diameter 2’; has a star south following, in angle of position measured 352.5 degrees by the micrometer; at a distance from it of 3”.”

The second entry under number 2165 comes from the next night’s survey, Sweep 274 (July 27, 1830). Right ascension calculates at 22 hours 23 minutes 15.7 seconds. Declination measures 104 degrees 60 minutes 23 seconds. Sir John’s concise description observes: “F; E; s b M; twilight commenced.”

His description translates as: “Faint; elongated; suddenly bright in the middle; twilight commenced.”

Sweep 37 (Aug. 5, 1826), which chronologically occurred as first of the four observations, supplies the next set of details. Right ascension is 22 hours 23 minutes 16.7 seconds, and declination is 104 degrees 59 minutes 51 seconds. Sir John’s description notes: “F; R; b M; 15’; by obs RA = 22^m 16^s.7, but this is an obvious mistake.”

His description transcribes as: “Faint; round; bright in the middle; right ascension by observation equals 22 minutes 16.7 seconds, but this is an obvious mistake.”

Details from Sweep 373, conducted Sept. 10, 1831, as the last of the four observations, close Sir John’s entries on NGC 7302. Right ascension is 22 hours 23 minutes 18.5 seconds. Declination is 104 degrees 58 minutes 57 seconds. Sir John’s briefly notes: “F; S; R; v s b m to a * 14 m.”

His description translates as: “Faint; small; round; very suddenly much brighter to star of the 14th magnitude.”

The takeaway for Sir John Herschel’s four observations of lenticular galaxy NGC 7302, discovered Oct. 3, 1785, in constellation Aquarius by his father, Uranus discoverer William Herschel, is that Sir John made his four observations with the same telescope used for his father’s discovery.

NGC 7302, lenticular galaxy in constellation Aquarius, discovered Oct. 3, 1785 by Uranus discoverer Sir William Herschel and observed four times between 1826 and 1831, by his son, Sir John Herschel; "Atlas Image courtesy of 2MASS/UMass/IPAC-Caltech/NASA/NSF": 2MASS (Two Micron All Sky Survey), Public Domain, via NASA/JPL-Caltech IPAC (Infrared Processing and Analysis Center)

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Sir William Herschel’s 20-foot reflecting telescope, through which Sir William discovered NGC 7302 on Oct. 3, 1785, and used for his son’s four observations of NGC 7302: W. Herschel, W. Bunce and J. Walker’s William Herschel’s Twenty-Foot Reflecting Telescope (1794 print), CC BY 4.0 International, via University of Cambridge Institute of Astronomy Library @ https://www.repository.cam.ac.uk/handle/1810/217286

NGC 7302, lenticular galaxy in constellation Aquarius, discovered Oct. 3, 1785 by Uranus discoverer Sir William Herschel and observed four times between 1826 and 1831, by his son, Sir John Herschel; "Atlas Image [or Atlas Image mosaic] obtained as part of the Two Micron All Sky Survey (2MASS), a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation.": Public Domain, via NASA/JPL-Caltech IPAC (Infrared Processing and Analysis Center) @ https://irsa.ipac.caltech.edu/cgi-bin/2MASS/PubGalPS/nph-galps?objstr=2MASXJ22322379-1407137

For further information:

Bratton, Mark. The Complete Guide to the Herschel Objects: Sir William Herschel’s Star Clusters, Nebulae and Galaxies. Cambridge, UK; New York NY; Melbourne, Australia; Madrid, Spain; Cape Town, South Africa; Singapore; São Paulo, Brazil; Delhi, India; Tokyo, Japan; Mexico City, Mexico: Cambridge University Press, 2011.

Dreyer, J.L.E. (John Louis Emil). “No. 7302.” In: “A New General Catalogue of Nebulae and Clusters of Stars, Being the Catalogue of the Late Sir John F.W. Herschel, Bart., Revised, Corrected, and Enlarged.” Memoirs of the Royal Astronomical Society, vol. XLIX, part I: 198. London, England: Royal Astronomical Society, 1888.
Available @ https://ia800501.us.archive.org/14/items/newgeneralcatalo00dreyrich/newgeneralcatalo00dreyrich.pdf
Available via HathiTrust @ https://hdl.handle.net/2027/osu.32435078053089?urlappend=%3Bseq=204

Dreyer, J.L.E. (John Louis Emil). “A New General Catalogue of Nebulae and Clusters of Stars, Being the Catalogue of the Late Sir John F.W. Herschel, Bart., Revised, Corrected, and Enlarged.” Memoirs of the Royal Astronomical Society, vol. XLIX, part I. London, England: Royal Astronomical Society, 1888.
Available @ https://ia800501.us.archive.org/14/items/newgeneralcatalo00dreyrich/newgeneralcatalo00dreyrich.pdf
Available via HathiTrust @ https://hdl.handle.net/2027/osu.32435078053089

Dreyer, J.L.E. (John Louis Emil). “A Supplement to Sir John Herschel’s ‘General Catalogue of Nebulae and Clusters of Stars.’ (Read February 26, 1877.).” The Transactions of the Royal Irish Academy, vol. XXVI (March 1878). Dublin, Ireland: Royal Irish Academy, 1878.
Available via Internet Archive @ https://archive.org/details/supplementtosirj00dreyrich/

Herschel, Sir John Frederick William. “Catalogue of Nebulae and Clusters of Stars. Received October 16, -- Read November 19, 1863.” Philosophical Transactions of the Royal Society of London. For the Year MDCCCLXIV [1864]. Vol. 154: 1-137. London, England: Taylor and Francis, MDCCCLXV (1865).
Available via Biodiversity Heritage Library (Natural History Museum Library, London) @ https://biodiversitylibrary.org/page/54093164
Available via JSTOR @ https://www.jstor.org/stable/108864

Herschel, Sir John F.W. (Frederick William). “A General Catalogue of Nebulae and Clusters of Stars, Arranged in Order of Right Ascension and Reduced to the Common Epoch 1860.0 (With Precessions Computed for the Epoch 1880.0). Received October 16, -- Read November 19, 1863.” Philosophical Transactions, Part I (1864): 1-137. London, England: Taylor and Francis, 1864.
Available via HathiTrust @ https://catalog.hathitrust.org/Record/001475323

Herschel, Sir John Frederick William. “No. 2165.” In: “Observations of Nebulae and Clusters of Stars, Made at Slough, With a Twenty-Feet Reflector, Between the Years 1825 and 1833. Received July 1, -- Read November 21, 1833.” Philosophical Transactions of the Royal Society of London, vol. 123 (1833): 473.
Available via Internet Archive @ https://archive.org/details/philtrans06301558/page/n114
Available via JSTOR @ https://www.jstor.org/stable/108003?seq=115#metadata_info_tab_contents

Herschel, Sir John Frederick William. “No. of Catalogue: 4802.” In: “Catalogue of Nebulae and Clusters of Stars. Received October 16, -- Read November 19, 1863.” Philosophical Transactions of the Royal Society of London. For the Year MDCCCLXIV [1864]. Vol. 154: 132. London, England: Taylor and Francis, MDCCCLXV (1865).
Available via Biodiversity Heritage Library (Natural History Museum Library, London) @ https://biodiversitylibrary.org/page/54093295
Available via JSTOR @ https://www.jstor.org/stable/108864?seq=132#metadata_info_tab_contents

Herschel, Sir John Frederick William. “Observations of Nebulae and Clusters of Stars, Made at Slough, With a Twenty-Feet Reflector, Between the Years 1825 and 1833. Received July 1, -- Read November 21, 1833.” Philosophical Transactions of the Royal Society of London, vol. 123 (1833): 359-505.
Available via JSTOR @ https://www.jstor.org/stable/108003

Herschel, William. “IV. 31.” In: “Catalogue of a Second Thousand of New Nebulae and Clusters of Stars; With a Few Introductory Remarks on the Construction of the Heavens. Read June 11, 1789.” Philosophical Transactions of the Royal Society of London, vol. LXXIX, part II (1789): 246. London, England: Lockyer Davis and Peter Elmsly, Printers to The Royal Society, MDCCLXXXIX.
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/51828776
Available via JSTOR @https://www.jstor.org/stable/106695

Herschel, William. “Catalogue of 500 New Nebulae, Nebulous Stars, Planetary Nebulae, and Clusters of Stars; With Remarks on the Construction of the Heavens. Read July 1, 1802.” Philosophical Transactions of the Royal Society of London. For the Year MDCCCII [1802] [vol. 92], part II: 477-528. London, England: W. Bulmer and Co., MDCCCII.
Available via Biodiversity Heritage Library (Smithsonian Libraries) @ https://biodiversitylibrary.org/page/49130796
Available via Biodiversity Heritage Library (University of Toronto -- Robarts Library) @ https://biodiversitylibrary.org/page/22894665
Available via JSTOR @ https://www.jstor.org/stable/107131

Herschel, William. “Catalogue of a Second Thousand of New Nebulae and Clusters of Stars; With a Few Introductory Remarks on the Construction of the Heavens. Read June 11, 1789.” Philosophical Transactions of the Royal Society of London, vol. LXXIX, part II (1789): 212-255. London, England: Lockyer Davis and Peter Elmsly, Printers to The Royal Society, MDCCLXXXIX.
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/51828742
Available via JSTOR @ https://www.jstor.org/stable/106695

Herschel, William. “Catalogue of One Thousand New Nebulae and Clusters of Stars. Read April 27, 1786.” Philosophical Transactions of the Royal Society of London, vol. LXXVI, part II (1786): 457-499. London, England: Lockyer Davis and Peter Elmsly, Printers to The Royal Society, MDCCLXXXVI.
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/48283813
Available via JSTOR @ https://www.jstor.org/stable/106639

Mullaney, James. The Herschel Objects and How to Observe Them. AST Astronomers’ Observing Guides. New York NY: Springer Science+Business Media LLC, 2007.

Mullaney, James; Wil Tirion. The Cambridge Atlas of Herschel Objects. Cambridge, England; New York NY; Melbourne, Australia; Madrid, Spain; Cape Town, South Africa; Singapore; São Paulo, Brazil; Delhi, India; Dubai, United Arab Emirates; Tokyo, Japan; Mexico City: Mexico: Cambridge University Press, 2011.

O’Meara, Steve. Herschel 400 Observing Guide: How to Find and Explore 400 Star Clusters, Nebulae, and Galaxies Discovered by William and Caroline Herschel. Cambridge, England; New York NY; Melbourne, Australia; Madrid, Spain; Cape Town, South Africa; Singapore; São Paulo, Brazil: Cambridge University Press, 2007.