Galactic Nebula IC 1284

IC 1283
IC 1283: Emission nebula in Sagittarius; TEC APO 140 FL refractor, f=882 mm; QHY 268M (CMOS); AstroPhysics 1200 GTO; HII 1x1 10x900 sec, R 1x1 18x300 sec, G 1x1 14x300 sec, B 1x1 18x300 sec; Astrofarm Tivoli, Namibia; © September 2022 Hansjörg Wälchli [46]

History

On 14 July 1830 John Herschel discovered a «double star, involved in a pretty bright large nebula 50".» He observed it again in the two following nights and sketched it. He cataloged the object as h 2002 and later as GC 4395, which became to NGC 6595 in Dreyer's «New General Catalogue». Lewis Swift independently found this reflection nebula on 12 July 1885. But his position for Sw II-62 is 45 seconds of RA too far west, hence it was listed by Dreyer as NGC 6590 unknowingly it was a double entry. Edward Emerson Barnard mentioned this object again and it received a third designation: IC 4700. By order of discovery, NGC 6595 should take precedence. [313, 364, 466]

Truman Safford discovered NGC 6589 on 28 August 1867. Lewis Swift independently discovered this reflection nebula on 12 July 1885 and recorded «Another D* in center of an eF, pL nebulosity; np of 2 [with NGC 6590]. Except for the inequality of the stars and the excessive faintness of the nebula, it would resemble the preceding [Sw II-62 = NGC 6590].» As Safford's discovery list was not published until 1887 when Dreyer had already compiled the NGC table, Swift was credited with the discovery. In 1905 Edward Emerson Barnard reported: «Stars 9.5 mag in nebulosity, extended, south preceding, north following» which was added as IC 4690 in Dreyer's «Second Index Catalogue» [315, 364]

IC 1284 was discovered by Barnard on a photographic plate taken with the 6" Willard lens on 31 May 1892. He noted: «An unknown nebulous star [BD -19°4953]. It is shown on the photograph to be nearly symmetrically surrounded with a faint diffused nebulosity about 15' in diameter. Perhaps this nebulosity is a little denser and more extensive following. Visually with the 12 inch, I cannot be certain of seeing the nebulosity on account of the brightness of the central star.» On another photographic plate taken with the 6" Willard lens in June 1892 he discovered IC 1283 and commented that BD -19° 4948 is nebulous and «the nebulosity is very small and principally noticeable on the southern side of the [9.3 magnitude] star.» [364]

In 1946 the Swedish astronomer Sven Cederblad published a study of bright diffuse galactic nebulae where he listed this nebula as Cederblad 157, consisting of four parts (A through D). [130]

The American astronomer Stewart Sharpless studied the photo plates of the «Palomar Observatory Sky Survey» made with the 48 inch Schmidt telescope and published in 1959 «A Catalogue of H II Regions». Nebula Sh 2-37 with a diameter of 20 arcminutes is identified with this region, containing stars HD 167722, HD 167815, HD 313098, which are within IC 1284. [270]

Physical Properties

IC 1284 is a star-forming region composed primarily of hydrogen. Its red glow comes from electrons within the hydrogen atoms. They are excited by the radiation from young stars, but lose energy afterwards and emit a specific colour or wavelength of light. NGC 6589 and NGC 6590 are reflection nebula, dust that scatters shorter, bluer wavelengths of light from nearby stars.

Revised+Historic NGC/IC Version 22/9, © 2022 Dr. Wolfgang Steinicke [277]
Name RA Dec Type bMag vMag B-V SB Dim PA z D(z) MD Dreyer Description Identification, Remarks
NGC 6589 18 16 51.7 -19 46 41 RN 5 × 3 D * in centre of eF, pL neby IC 4690; LBN 46; ESO 590-N14
NGC 6590 18 17 04.8 -19 51 58 dup 7.0 11 1.640 D * in centre of pF, pL, R neby NGC 6595; IC 4700; ESO 590-SC15; OCL 31; CED 157B; LBN 43; DG 150
NGC 6595 18 17 04.8 -19 51 58 EN+OCL 7.0 11 1.640 F, pL, cE, ** inv h 2002; GC 4395; NGC 6590; IC 4700; ESO 590-SC15; OCL 31; CED 157B; LBN 43; DG 150
IC 1283 18 17 16.7 -19 45 44 EN 3 × 3 1.800 * 9.3 nebulous in Sh2-37, part of IC 1284
IC 1284 18 17 39.5 -19 40 19 EN+* 17 × 15 1.700 * 7.6 in neb, 15' diam ESO 590-*N16; CED 157D; in Sh2-37
IC 4690 18 16 51.7 -19 46 41 dup 5 × 3 * 9.5 in neb, E spnf NGC 6589; LBN 46; ESO 590-N14
IC 4700 18 17 04.8 -19 51 58 dup 7.0 11 * 9.4 in dense neb NGC 6590; NGC 6595; ESO 590-SC15; OCL 31; CED 157B; LBN 43; DG 150

Finder Chart

IC 1284 is located in the constellation Sagittarius, approximately 1° south of Messier 24. It can best be seen in the months of June to August. Then the constellation is highest above the southern horizon.

Finder Chart Galactic Nebula IC 1284
Galactic Nebula IC 1284 in constellation Sagittarius. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Objects Within a Radius of 15°

References

  • [46] Astrofotografie mit Hansjörg Wälchli; upsky.ch
  • [130] «Studies of bright diffuse galactic nebulae with special regard to their spatial distribution.» Cederblad, S.; Lund Medd. Astron. Obs. Ser. II, Vol. 119, p. 1-166 (1946); Bibcode:1946MeLuS.119....1C
  • [149] SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
  • [160] The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
  • [270] «Catalogue of Bright Nebulae» Lynds, Beverly T.; Astrophysical Journal Supplement, vol. 12, p.163 (1965); DOI:10.1086/190123
  • [277] «Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)
  • [313] «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» Dreyer, J. L. E. (1888); Memoirs of the Royal Astronomical Society. 49: 1–237; Bibcode:1888MmRAS..49....1D
  • [315] «Second Index Catalogue of Nebulae and Clusters of Stars; containing objects found in the years 1895 to 1907, with Notes and Corrections to the New General Catalogue and to the Index Catalogue for 1888–94» Dreyer, J. L. E. (1910); Memoirs of the Royal Astronomical Society. 59: 105–198; Bibcode:1910MmRAS..59..105D
  • [364] Steve Gottlieb's NGC Notes; astronomy-mall.com/Adventures.In.Deep.Space/steve.ngc.htm
  • [466] «Observations of nebulæ and clusters of stars, made at Slough, with a twenty-feet reflector, between the years 1825 and 1833» John Frederick William Herschel, Philosophical Transactions of the Royal Society of London, 1 January 1833, Pages: 359-505; DOI:10.1098/rstl.1833.0021