Sir John Herschel Made Three Observations of the Bow Tie Nebula NGC 40

Summary: John Herschel made three observations of the Bow Tie Nebula NGC 40, the planetary nebula discovered Nov. 25, 1788, by his father, William Herschel.

On Dec. 20, 1829, English polymath Sir John Herschel made his first of three observations of NGC 40, a planetary nebula in constellation Cepheus discovered by his father, Uranus discoverer Sir William Herschel, Nov. 25, 1788; 1829 miniature watercolor of John Herschel by Swiss portrait painter Alfred Edward Chalon, painted as complement to portrait of Margaret Brodie Stewart (Aug. 16, 1810-Aug. 3, 1884) for their marriage March 3, 1829: Public Domain, via Wikimedia Commons

Sir John Herschel made three observations of the Bow Tie Nebula NGC 40, a planetary nebula in Cepheus the King constellation discovered Nov. 25, 1788, by his father, Sir William Herschel.

German-British astronomer and composer Sir Frederick William Herschel (Nov. 15, 1738-Aug. 25, 1822) discovered NGC 40 seven years eight-plus months after his March 13, 1781, discovery of Uranus, the solar system’s seventh planet. Sir William made his discovery of NGC 40 at his last residence, known as Observatory House, in Slough, Royal County of Berkshire, South East England.

Sir William’s discovery of NGC 40 appears in his Catalogue of a Second Thousand of New Nebulae and Clusters of Stars, published in 1789. The discovery is entered as number 58 in the category of "IV. Fourth claſs. Planetary nebulae.”

Sir William’s only child, English polymath Sir John Frederick William Herschel, 1st Baronet (March 7, 1792-May 11, 1871), shared his father’s interest in astronomy. In 1852, Sir John named the four then-known moons of his father’s planet: Ariel, Umbriel, Titania and Oberon.

In 1833, Sir John published Observations of Nebulae and Clusters of Stars, Made at Slough, With a Twenty-Feet Reflector, Between the Years 1825 and 1833. The astronomical catalogue comprised his and his father’s observations. He arranged the catalogue’s entries “in order of right ascension,” the celestial equivalent of terrestrial longitude.

Sir William’s Cepheid planetary nebula appears as entry number 8 in Sir John’s 1833 publication. Sir William’s designation for his discovery, IV-58, is given as the synonym for entry number 8. Sir John noted three observations of his entry number 8.

The observations were made during sweeps 228, 378 and 380. Sweep 228 occurred Dec. 20, 1829. Sweep 378 took place Oct. 29, 1831. On Nov. 2, 1831, Sir John conducted sweep 380. Sir William and Sir John referred to their telescopic surveys of the sky as “sweeps of the heavens.”

Sir John began entry number 8 with details from sweep 378 (Oct. 29, 1831), which occurred chronologically as the second of his three observations. He described his observation of IV-58 as: “A * 10 m with strong neb atmosph 15” diameter. Exactly R and p suddenly fading away makes a D * class 5 with a * preceding.” His description translates as: “A star of the 10th magnitude with strong nebulous atmosphere, diameter of 15 arc seconds. Exactly round and pretty, suddenly fading away, makes a class 5 double star with a preceding star.”

The second set of details for entry number 8 came from sweep 380 (Nov. 2, 1831), which was actually the third, or most recent, of his three observations. His second observation remarked: “The L * of a D * strongly affected with a neb burr. Pos 241°^.4; △ AR = 25^s; 10 and 12 m.” His description translates as: “The large star of a double star strongly affected with a nebulous burr. Angle of position measured 241°^.4 by the micrometer; right ascension 25 seconds. 10th and 12th magnitude.”

Sweep 228 (Dec. 20, 1829), which chronologically marked Sir John’s first sighting of IV-58, supplied the third set of details for entry number 8. Sir John noted: “A star 11 m with a luminous atm 30 or 40” diam.” His description translates as: “A star of the 11th magnitude with a luminous atmosphere, diameter of 30 or 40 arcseconds.”

In 1865, Sir John published Catalogue of Nebulae and Clusters of Stars. The catalogue’s entry number 20 links with his 1833 catalogue’s entry number 8 and with Sir William’s IV-58 entry. He constructed his descriptions in the 1865 catalogue by assembling and comparing all observations and remarks given in his and his father’s catalogues. Sir John’s composite description of object IV-58 derived from his father’s sole discovery observation and from Sir John’s three observations.

Entry number 20 bears the composite description: “vF; vS; R; vsmbM *10; *12 241°^.4; 25^s.” The description translates as: “Very faint; very small; round; very suddenly much brighter in the middle, star of the 10th magnitude; star of the 12th magnitude, micrometrically measured 241°.4; 25 seconds.”

Sir William’s IV-58 and Sir John’s synonymous entries are now known as NGC 40. Danish-Irish astronomer John Louis Emil Dreyer (Feb. 13, 1852-Sept. 14, 1926) published A New General Catalogue in 1888 as a compilation of discoveries and observations by the father-and-son Herschels; Sir William’s sister Caroline (March 16, 1750-Jan. 9, 1848); and other observational astronomers.

The takeaway for Sir John Herschel’s three observations of the Bow Tie Nebula NGC 40 is that the English polymath’s observations revisited the Cepheid planetary nebula discovered Nov. 25, 1785, by his father, Uranus discoverer Sir William Herschel.

Hubble Space Telescope WFPC2 (Wide Field Planetary Camera 2) color image of NGC 40 (lower left), with the planetary nebula's central star; RA 00:12:56.42, DEC 72:31:37.0; Nov. 10, 1995; image NGC40 (color) WFPC2 f814w/f555w PC1 06119_01: HLA (Hubble Legacy Archive) via HLA-STScI (Space Telescope Science Institute)

Acknowledgment

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

Image credits:

On Dec. 20, 1829, English polymath Sir John Herschel made his first of three observations of NGC 40, a planetary nebula in constellation Cepheus discovered by his father, Uranus discoverer Sir William Herschel, Nov. 25, 1788; 1829 miniature watercolor of John Herschel by Swiss portrait painter Alfred Edward Chalon, painted as complement to portrait of Margaret Brodie Stewart (Aug. 16, 1810-Aug. 3, 1884) for their marriage March 3, 1829: Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:John_Herschel00.jpg

Hubble Space Telescope WFPC2 (Wide Field Planetary Camera 2) color image of NGC 40 (lower left), with the planetary nebula's central star; RA 00:12:56.42, DEC 72:31:37.0; Nov. 10, 1995;  image NGC40 (color) WFPC2 f814w/f555w PC1 06119_01: HLA (Hubble Legacy Archive) via HLA-STScI (Space Telescope Science Institute) @ http://hla.stsci.edu/hlaview.html#Inventory|filterText%3D%24filterTypes%3D|query_string=ngc%2040

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. 40.” 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: 15. 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=21

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 Frederick William. “No. 8.” 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): 365.
Available via JSTOR @ https://www.jstor.org/stable/108003?seq=7#metadata_info_tab_contents

Herschel, Sir John Frederick William. “No. of Catalogue: 20.” 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: 46. London, England: Taylor and Francis, MDCCCLXV (1865).
Available via Biodiversity Heritage Library (Natural History Museum Library, London) @ https://biodiversitylibrary.org/page/54093209
Available via JSTOR @ https://www.jstor.org/stable/108864?seq=46#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, Sir John F.W. (Frederick William). Results of Astronomical Observations Made During the Years 1834, 5, 6, 7, 8, at the Cape of Good Hope: Being the Completion of a Telescopic Survey of the Whole Surface of the Visible Heavens, Commenced in 1825. London, England: Smith, Elder and Co., 1847.
Available via Internet Archive @ https://archive.org/details/resultsofastrono00hers/

Herschel, Sir John F.W. (Frederick William). “Synoptic Table of the Dates of the Sweeps.” In: Results of Astronomical Observations Made During the Years 1834, 5, 6, 7, 8, at the Cape of Good Hope: Being the Completion of a Telescopic Survey of the Whole Surface of the Visible Heavens, Commenced in 1825: 130-131. London, England: Smith, Elder and Co., 1847.
Available via Internet Archive @ https://archive.org/details/resultsofastrono00hers/page/130

Herschel, William. “IV. 58.” 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): 248. London, England: Lockyer Davis and Peter Elmsly, Printers to The Royal Society, MDCCLXXXIX.
Available via Biodiversity Heritage Library @ https://biodiversitylibrary.org/page/51828778
Available via JSTOR @https://www.jstor.org/stable/106695

Herschel, William. “IV-64.” In: “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: 520. London, England: W. Bulmer and Co., MDCCCII.
Available via Biodiversity Heritage Library (Smithsonian Libraries) @ https://biodiversitylibrary.org/page/49130839
Available via Biodiversity Heritage Library (University of Toronto -- Robarts Library) @ https://biodiversitylibrary.org/page/22894708
Available via JSTOR @ https://www.jstor.org/stable/107131

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

Lassell, W. (William). “Beobachtungen der Uranus-Satelliten.” Astronomische Nachrichten, vol. 34 (vier und dreissigster band), no. 812: 325-328. June 1852.
Available via Harvard ADSABS (NASA Astrophysics Data System Abstracts) @ http://articles.adsabs.harvard.edu/full/1852AN.....34..325.
Available via HathiTrust @ https://hdl.handle.net/2027/umn.31951000600709p?urlappend=%3Bseq=183

Marriner, Derdriu. “Bow Tie Nebula NGC 40 Is a Planetary Nebula in Constellation Cepheus.” Earth and Space News. Wednesday, Nov. 6, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/11/bow-tie-nebula-ngc-40-is-planetary.html

Marriner, Derdriu. “Globular Cluster NGC 5634 Lies Midway Between Iota and Mu Virginis.” Earth and Space News. Wednesday, Feb. 27, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/02/globular-cluster-ngc-5634-lies-midway.html

Marriner, Derdriu. "Herschel Crater Hosts Eight Satellites in South Central Lunar Near Side." Earth and Space News. Wednesday, Aug. 31, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/08/herschel-crater-hosts-eight-satellites.html

Marriner, Derdriu. "Lunar Crater Herschel Honors German-British Astronomer William Herschel." Earth and Space News. Wednesday, Aug. 24, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/08/lunar-crater-herschel-honors-german.html

Marriner, Derdriu. "Star Hopping Between Gamma Cassiopeiae and Gamma Cephei Locates NGC 40." Earth and Space News. Wednesday, Nov. 13, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/11/star-hopping-between-gamma-cassiopeiae.html

Marriner, Derdriu. “Uranus the Blue Green Ice Giant: Sideways Seventh Planet From the Sun.” Earth and Space News. Friday, March 13, 2015.
Available @ https://earth-and-space-news.blogspot.com/2015/03/uranus-blue-green-ice-giant-sideways.html

Marriner, Derdriu. “Uranus Discovery 234 Years Ago on March 13, 1781, by Sir William Herschel.” Earth and Space News. Friday, March 13, 2015.
Available @ https://earth-and-space-news.blogspot.com/2015/03/uranus-discovery-234-years-ago-on-march.html

Marriner, Derdriu. “William Herschel Discovered Bow Tie Nebula NGC 40 Nov. 25, 1788.” Earth and Space News. Wednesday, Nov. 20, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/11/william-herschel-discovered-bow-tie.html

Marriner, Derdriu. “William Herschel Discovered NGC 665 and NGC 673 Sept. 4, 1786.” Earth and Space News. Wednesday, Aug. 28, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/08/william-herschel-discovered-lenticular.html

Marriner, Derdriu. “William Herschel Discovered NGC 6818, Little Gem Nebula, Aug. 8, 1787.” Earth and Space News. Wednesday, Aug. 7, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/08/william-herschel-discovered-ngc-6818.html

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.

Steinicke, Wolfgang. “’Historic WH’ Columns.” Astronomie-Homepage von Wolfgang Steinicke > Current Matters: Historic WH > Discovery and Cataloguing of Nebulae and Star Clusters > 2. Historical Catalogues: W. Herschel: Historic WH > “Historic WH” -- Explanation. Jan. 14, 2018.
Available @ http://www.klima-luft.de/steinicke/ngcic/Expl_Hist_WH.htm

Steinicke, Wolfgang. Revised New General Catalogue and Index Catalogue. Jan. 14, 2018.
Available @ http://www.klima-luft.de/steinicke/ngcic/rev2000/Explan.htm#3.2