# Goldfish galaxy

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Radio galaxy located in the constellation Draco

Goldfish galaxy SDSS image of the Goldfish galaxy Observation data (J2000.0 epoch) Constellation Draco Right ascension 17h 13m 03.78s[1] Declination +64° 07′ 01.71″[1] Redshift 0.080923[1] Heliocentric radial velocity 24,260 km/s ± 4[1] Distance 1,176.3 ± 82.4 Mly (360.67 ± 25.25 Mpc) Group or cluster Abell 2255 magnitude (J) 13.48[1] Characteristics Type Radio galaxy[1] Size ~192,000 ly (58.9 kpc) (estimated)[1] Other designations 14W 118, 7C 1713+6407a, ABELL 2255:[DMM2003] 2, PGC 59858, SDSS J171303.78+640701.6, 2MASX J17130384+6407014[1]

The **Goldfish galaxy**, also known as **7C 1713+6407a**, is a [radio galaxy](/source/Radio_galaxy) located in the constellation of [Draco](/source/Draco_(constellation)). The [redshift](/source/Redshift) of the galaxy is z=0.080[1] and it was first discovered by [astronomers](/source/Astronomer) in 1974 as an [astronomical radio source](/source/Astronomical_radio_source) whom they described it having a steep [radio spectrum](/source/Radio_spectrum).[2] It is considered to be a member of the rich [galaxy cluster](/source/Galaxy_cluster) [Abell 2255](/source/Abell_2255), alongside the [Beaver galaxy](/source/Beaver_galaxy), the [Embryo galaxy](https://en.wikipedia.org/w/index.php?title=Embryo_galaxy&action=edit&redlink=1), the [Original TRG](/source/Original_TRG), and the [Bean Galaxy](/source/Bean_galaxy).[3][4][5]

## Description

The Goldfish galaxy is classified as an [elliptical galaxy](/source/Elliptical_galaxy) with an [active galactic nucleus](/source/Active_galactic_nucleus) (AGN).[3] It is a head-tail radio galaxy[4] or alternatively a [Fanaroff-Riley class](/source/Fanaroff%E2%80%93Riley_classification) type I narrow-tailed radio galaxy.[6][7] When observed, it is found to have a weak tail feature. The head feature on the other hand, is shown little [polarized](/source/Polarization_(cosmology)) by around 4%.[4]

Radio imaging made at 1.4 [GHz](/source/Hertz) [frequencies](/source/Frequency) has found the head of the Goldfish galaxy as clearly resolved with two [radio jets](/source/Astrophysical_jet) on opposite sides, one of them displaying a bend degree towards the east. A compact [radio](/source/Radio) core is detected at 5 GHz frequencies. When imaged at 15 GHz, the nucleus and only the part of the northern jet is found.[7] The tail feature of the Goldfish galaxy is shown to have an total extension of 261 [kiloparsecs](/source/Parsec) and further extended by around 180 kiloparsecs towards the direction of southeast.[8] Earlier observations depicted the nucleus as unresolved.[9]

Further observations at sub-arcsecond resolutions have detected traces of [radio emission](/source/Radio_wave) emitting out from the tail region of the Goldfish galaxy. Evidence also found the tail exhibits a [helical](/source/Helix) morphology with jets appearing to spiral around each other before merging back into a single tail feature. A region of increased [surface brightness](/source/Surface_brightness) is detected about 170 kiloparsecs away from the core region.[6]

## References

1. ^ [***a***](#cite_ref-ned_1-0) [***b***](#cite_ref-ned_1-1) [***c***](#cite_ref-ned_1-2) [***d***](#cite_ref-ned_1-3) [***e***](#cite_ref-ned_1-4) [***f***](#cite_ref-ned_1-5) [***g***](#cite_ref-ned_1-6) [***h***](#cite_ref-ned_1-7) [***i***](#cite_ref-ned_1-8) ["NED Search results for Goldfish galaxy"](https://ned.ipac.caltech.edu/byname?objname=LEDA+59858&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1). *NASA/IPAC Extragalactic Database*. Retrieved 2026-02-14.

1. **[^](#cite_ref-2)** Slingo, A.; Baldwin, J. E. (1974-08-01). ["The Structure and Origin of Radio Sources with Very Steep Spectra"](https://doi.org/10.1093%2Fmnras%2F168.2.307). *Monthly Notices of the Royal Astronomical Society*. **168** (2): 307–330. [doi](/source/Doi_(identifier)):[10.1093/mnras/168.2.307](https://doi.org/10.1093%2Fmnras%2F168.2.307). [ISSN](/source/ISSN_(identifier)) [0035-8711](https://search.worldcat.org/issn/0035-8711).

1. ^ [***a***](#cite_ref-:0_3-0) [***b***](#cite_ref-:0_3-1) Davis, David S.; Miller, Neal A.; Mushotzky, Richard F. (November 2003). ["Chandra Observations of Point Sources in A2255"](http://web.archive.org/web/20220629104758/https://ui.adsabs.harvard.edu/abs/2003ApJ...597..202D/abstract). *The Astrophysical Journal*. **597** (1): 202–209. [arXiv](/source/ArXiv_(identifier)):[astro-ph/0307370](https://arxiv.org/abs/astro-ph/0307370). [Bibcode](/source/Bibcode_(identifier)):[2003ApJ...597..202D](https://ui.adsabs.harvard.edu/abs/2003ApJ...597..202D). [doi](/source/Doi_(identifier)):[10.1086/378384](https://doi.org/10.1086%2F378384). [ISSN](/source/ISSN_(identifier)) [0004-637X](https://search.worldcat.org/issn/0004-637X). Archived from [the original](https://ui.adsabs.harvard.edu/abs/2003ApJ...597..202D/abstract) on 2022-06-29.

1. ^ [***a***](#cite_ref-:1_4-0) [***b***](#cite_ref-:1_4-1) [***c***](#cite_ref-:1_4-2) Harris, D. E.; Kapahi, V. K.; Ekers, R. D. (February 1980). ["Westerbork synthesis observations of 8 clusters of galaxies which contain tailed radio galaxies"](https://articles.adsabs.harvard.edu/pdf/1980A%26AS...39..215H). *Astronomy and Astrophysics, Suppl. Ser*. **39** (39): 215–233. [Bibcode](/source/Bibcode_(identifier)):[1980A&AS...39..215H](https://ui.adsabs.harvard.edu/abs/1980A&AS...39..215H).

1. **[^](#cite_ref-5)** Pizzo, R. F.; Bruyn, A. G. de (2009-11-01). ["Radio spectral study of the cluster of galaxies Abell 2255"](https://www.aanda.org/articles/aa/abs/2009/44/aa12465-09/aa12465-09.html). *Astronomy & Astrophysics*. **507** (2): 639–659. [arXiv](/source/ArXiv_(identifier)):[0909.5198](https://arxiv.org/abs/0909.5198). [Bibcode](/source/Bibcode_(identifier)):[2009A&A...507..639P](https://ui.adsabs.harvard.edu/abs/2009A&A...507..639P). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/200912465](https://doi.org/10.1051%2F0004-6361%2F200912465). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. ^ [***a***](#cite_ref-:2_6-0) [***b***](#cite_ref-:2_6-1) Rubeis, E. De; Bondi, M.; Botteon, A.; Weeren, R. J. van; Jong, J. M. G. H. J. de; Rudnick, L.; Brunetti, G.; Rajpurohit, K.; Gheller, C.; Röttgering, H. J. A. (2025-07-01). ["Revealing the intricacies of radio galaxies and filaments in the merging galaxy cluster Abell 2255 - I. Insights from deep LOFAR-VLBI sub-arcsecond resolution images"](https://www.aanda.org/articles/aa/abs/2025/07/aa55268-25/aa55268-25.html). *Astronomy & Astrophysics*. **699**: A229. [arXiv](/source/ArXiv_(identifier)):[2505.13595](https://arxiv.org/abs/2505.13595). [Bibcode](/source/Bibcode_(identifier)):[2025A&A...699A.229D](https://ui.adsabs.harvard.edu/abs/2025A&A...699A.229D). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/202555268](https://doi.org/10.1051%2F0004-6361%2F202555268). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. ^ [***a***](#cite_ref-:3_7-0) [***b***](#cite_ref-:3_7-1) Gregory, Beatrice Terni de; Feretti, Luigina; Giovannini, Gabriele; Govoni, Federica; Murgia, Matteo; Perley, Rick A.; Vacca, Valentina (2017-11-07), "Narrow head-tail radio galaxies at very high resolution", *Astronomy & Astrophysics*, **608**: A58, [arXiv](/source/ArXiv_(identifier)):[1709.00223](https://arxiv.org/abs/1709.00223), [Bibcode](/source/Bibcode_(identifier)):[2017A&A...608A..58T](https://ui.adsabs.harvard.edu/abs/2017A&A...608A..58T), [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201730878](https://doi.org/10.1051%2F0004-6361%2F201730878)

1. **[^](#cite_ref-8)** Pizzo, R. F.; Bruyn, A. G. de; Bernardi, G.; Brentjens, M. A. (2011-01-01). ["Deep multi-frequency rotation measure tomography of the galaxy cluster A2255"](https://www.aanda.org/articles/aa/pdf/2011/01/aa14158-10.pdf) (PDF). *Astronomy & Astrophysics*. **525**: A104. [arXiv](/source/ArXiv_(identifier)):[1008.3530](https://arxiv.org/abs/1008.3530). [Bibcode](/source/Bibcode_(identifier)):[2011A&A...525A.104P](https://ui.adsabs.harvard.edu/abs/2011A&A...525A.104P). [doi](/source/Doi_(identifier)):[10.1051/0004-6361/201014158](https://doi.org/10.1051%2F0004-6361%2F201014158). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

1. **[^](#cite_ref-9)** L., Feretti; H., Boehringer; G., Giovannini; D., Neumann (January 1997). "The radio and X-ray properties of Abell 2255". *Astronomy and Astrophysics*. **317**: 432. [arXiv](/source/ArXiv_(identifier)):[astro-ph/9607027](https://arxiv.org/abs/astro-ph/9607027). [Bibcode](/source/Bibcode_(identifier)):[1997A&A...317..432F](https://ui.adsabs.harvard.edu/abs/1997A&A...317..432F). [ISSN](/source/ISSN_(identifier)) [0004-6361](https://search.worldcat.org/issn/0004-6361).

## External links

- Goldfish galaxy on [WikiSky](/source/WikiSky): [DSS2](http://www.wikisky.org/?object=Goldfish+galaxy&img_source=DSS2), [SDSS](http://www.wikisky.org/?object=Goldfish+galaxy&img_source=SDSS), [GALEX](http://www.wikisky.org/?object=Goldfish+galaxy&img_source=GALEX), [IRAS](http://www.wikisky.org/?object=Goldfish+galaxy&img_source=IRAS), [Hydrogen α](http://www.wikisky.org/?object=Goldfish+galaxy&img_source=HALPHA), [X-Ray](http://www.wikisky.org/?object=Goldfish+galaxy&img_source=RASS), [Astrophoto](http://www.wikisky.org/?object=Goldfish+galaxy&img_source=IMG_all), [Sky Map](http://www.wikisky.org/?object=Goldfish+galaxy), [Articles and images](http://www.wikisky.org/starview?object=Goldfish+galaxy)

- [Goldfish galaxy on SIMBAD](https://simbad.u-strasbg.fr/simbad/sim-id?Ident=2MASX%20J17130384%2B6407014&NbIdent=1)

v t e Constellation of Draco List of stars in Draco Draco in Chinese astronomy Stars Bayer α (Thuban) β (Rastaban) γ (Eltanin) δ (Altais) ε (Tyl) ζ (Aldhibah) η (Athebyne) θ ι (Edasich) κ λ (Giausar) μ (Alrakis) ν (Kuma) ξ (Grumium) ο π ρ σ (Alsafi) τ υ φ χ ψ1 (Dziban) ψ2 ω Flamsteed 4 6 7 (Tianyi) 8 (Taiyi) 10 (i) 15 (A) 18 (g) 19 (h) 26 36 39 (b) 42 (Fafnir) 45 (d) 50 59 64 (e) 68 Variable TW YY AG BY CL CM CX DO EK HP V581 HR 3751 4126 4934 5811 6237 6518 6618 (Alruba) 6817 7137 7783 HD 109246 (Funi) 101364 128717 147379 156279 158259 176693 191939 Other 2MASS 1237+6526 2MASS J17554042+6551277 G 240-72 GD 356 Gliese 420 Gliese 625 Gliese 687 GRW +70 8247 Kepler-4 Kepler-10 Kepler-12 Kepler-90 Kepler-296 KOI-256 LP 71-82 Qatar-1 SDSS J1240+6710 Struve 2398 TOI-1136 WD 1856+534 WISE 1647+5632 WISE 1841+7000 Exoplanets HD 139357 b HD 167042 b ι Dra b (Hypatia) Kepler-4b Kepler-10b c Kepler-12b Kepler-90e f g h i Kepler-296b c d e f TOI-1452 b TrES-2b Star clusters LAMOST 1 Nebulae Cat's Eye Nebula NGC 6742 Galaxies NGC 3147 3197 3735 4121 4125 4221 4236 4319 4331 4332 4363 4441 4513 4545 4589 5678 5777 5866 5866B 5879 5905 5907 5949 5963 5965 5982 5985 6090 6248 6285 6286 6338 6340 6365 6373 6394 6412 6503 6505 6566 6621 6622 6670 6676 6786 6789 Other 1ES 1927+654 1ES 1959+650 3C 249.1 3C 305 3C 319 3C 343 3C 343.1 3C 351 3C 356 3C 371 3C 380 3C 390.3 3C 401 4C +72.26 4C 73.08 8C 1241+735 Abell 2218 BCG Bean galaxy Beaver galaxy BZQ J1727+5510 Draco Dwarf Draco II GB 1508+5714 Goldfish galaxy H1821+643 HFLS3 IERS B1946+708 IRAS F17179+5444 IRAS 18580+6527 J120011.1+680924.8 KKR 25 Markarian 817 Markarian 876 Original TRG PGC 39058 Porphyrion QSO B1823+568 RGZ J172749.5+534647 S5 1803+784 S5 2007+777 SDSS J1715+6008 Tadpole Galaxy UGC 9391 UGC 9405 UGC 11241 UGC 11411 WISEA J145223.62+611707.5 WN B1851+5707 Galaxy clusters Abell 2218 CL1358+62 Draco Supercluster NGC 5866 Group Astronomical events SN 2003jb SN 2005B SN 2016aps Swift J1644+57 Category

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Adapted from the Wikipedia article [Goldfish galaxy](https://en.wikipedia.org/wiki/Goldfish_galaxy) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Goldfish_galaxy?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.