NGC 684

{{Short description|Spiral galaxy in the constellation Triangulum}}

{{Infobox Galaxy

| name = NGC 684

| image = NGC684 - SDSS DR14.jpg

| caption = NGC 684 (SDSS)

| epoch = J2000.0

| constellation name = Triangulum

| ra = {{RA|01|50|14.0407}}

| dec = {{DEC|+27|38|44.472}}

| z = 0.011798

| h_radial_v = {{nowrap|3537 ± 1 km/s}}

| dist_ly = {{convert|41.400 ± 0.960|Mpc|Mly|abbr=on|lk=on|order=flip}}{{r|ned}}

| group_cluster = NGC 684 group (LGG 32)

| appmag_b = 13.30

| appmag_v = 12.50

| type = Sb edge-on

| size = ~{{convert|42.15|kpc|ly|abbr=on|lk=on|order=flip}} (estimated){{r|ned}}

| size_v = {{Val|3.2|×|0.6|u=arcminute}}{{r|ned}}

| names = {{odlist | PGC= 6759 | MCG= +04-05-017 | IC= 165 | UGC= 1292 | CGCG= 482-022 | IRAS= 01474+2724}}

}}

NGC 684 is a spiral galaxy approximately 135 million light-years away from Earth in the constellation of Triangulum. It was discovered by William Herschel on October 26, 1786. Edward Swift, Lewis' son, found this galaxy again on 18 Jan 1890 while "searching for Swift's Comet." and it was reported as a new object in list IX-6.

NGC 684 Group

NGC 684 is the largest member of a group of galaxies named after it (also known as LGG 32), which includes the galaxies NGC 670 and IC 1731.{{cite journal | bibcode=1993A&AS..100...47G | title=General study of group membership. II. Determination of nearby groups | last1=Garcia | first1=A. M. | journal=Astronomy and Astrophysics Supplement Series | date=1993 | volume=100 | page=47}}

Supernovae

Two supernovae have been observed in NGC 684:

SN{{nbsp}}2021ass (type{{nbsp}}II, mag. 18.1122) was discovered by the Zwicky Transient Facility on 18 January 2021.{{cite web | website=Transient Name Server | title=SN{{nbsp}}2021ass | url=https://www.wis-tns.org/object/2021ass | publisher = IAU | access-date=4 September 2024}}
SN{{nbsp}}2025aml (type{{nbsp}}II, mag. 18.1168) was discovered by the Zwicky Transient Facility on 31 January 2025.{{cite web | website=Transient Name Server | title=SN{{nbsp}}2025aml | url=https://www.wis-tns.org/object/2025aml | publisher = IAU | access-date=31 January 2025}}

References

{{reflist|refs=

{{cite web

| website = NASA/IPAC Extragalactic Database

| publisher = NASA and Caltech

| url = https://ned.ipac.caltech.edu/byname?objname=NGC+0684

| title=Results for object NGC 0684

| access-date = 4 December 2017}}

{{cite web|title=Revised NGC Data for NGC 684|url=http://spider.seds.org/ngc/revngcic.cgi?NGC684|website=spider.seds.org|access-date=December 9, 2017}}

{{cite web|title=Data for NGC 684 | url=http://www.astronomy-mall.com/Adventures.In.Deep.Space/NGC%201%20-%20999%20(11-30-17).htm | website=www.astronomy-mall.com | access-date=December 9, 2017}}

}}