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NGC 918

{{Short_description|Barred spiral galaxy in the constellation Aries}}

{{Sky|02|25|50.7648|+|18|29|46.987}}

{{Infobox galaxy

| name = NGC 918

| image = File:N918s.jpg

| caption = NGC 918 by the Mount Lemmon SkyCenter

| constellation name = Aries

| epoch = J2000

| type = SAB(rs)c{{cite web| title=NASA/IPAC Extragalactic Database |url=http://ned.ipac.caltech.edu/cgi-bin/objsearch?search_type=Obj_id&objid=6740&objname=22&img_stamp=YES&hconst=73.0&omegam=0.27&omegav=0.73&corr_z=1#BasicData_0 |website=ned.ipac.caltech.edu | access-date=19 June 2019 }}

| ra = {{RA|02|25|50.7648}}{{r|ned}}

| dec = {{DEC|+18|29|46.987}}{{r|ned}}

| dist_ly = 20.6±1.5 mpc We obtain the distance that separates us from a galaxy using Hubble's law: v = Hod, where Ho is the Hubble constant (70 ± 5 (km / s) / Mpc). The relative uncertainty Δd / d over the distance is equal to the sum of the relative uncertainties of the velocity and Ho.

| appmag_b = 16.0{{cite simbad|title=NGC 918|access-date=19 June 2019}}

| appmag_v = 15.01

| h_radial_v = {{nowrap|1510 ± 1 km/s}}

| z = 0.005037

| size = ~{{convert|21.63|kpc|ly|abbr=on|lk=on|order=flip}} (estimated){{r|ned}}

| size_v = {{Val|3.5|×|2.0|u=arcminute}}{{r|ned}}

| names = {{odlist | IRAS= 02230+1816 | CGCG= 462-011 | MCG= +03-07-011 | UGC= 1888 | PGC= 9236}}{{r|ned}}

}}

NGC 918 is a barred spiral galaxy in the constellation Aries, about 67 million light years from the Milky Way. It was discovered by John Herschel on Jan 11, 1831.{{cite web |last1=Seligman |first1=Courtney |title=New General Catalog Objects: NGC 900 - 949 |url=https://cseligman.com/text/atlas/ngc32a.htm#3294 |website=New General Catalog Objects: NGC 900 - 949 |access-date=19 June 2019}}

The brightness class of NGC 918 is III and it has a broad line of neutral hydrogen. NGC 918 is also an active nucleus galaxy (AGN). Moreover, it is a field galaxy which does not belong to a cluster or group and is therefore gravitationally isolated.{{Cite web|url=http://ned.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=ngc+918&img_stamp=YES|title=Your NED Search Results|website=ned.ipac.caltech.edu}}

Many non-redshift measures give a distance of 19,115 ± 6,160 Mpc (~62,3 million ly),{{Cite web|url=https://ned.ipac.caltech.edu/cgi-bin/nDistance?name=NGC+918|title=NED Query Results for NGC 918|website=ned.ipac.caltech.edu}} which is within the distances calculated using the value shift.

Supernovae

Two supernovae have been observed in NGC 918:

  • SN 2009js (type II, mag. 17.2) was discovered by Kōichi Itagaki and independently by the Lick Observatory Supernova Search (LOSS) on October 11, 2009.{{cite journal | bibcode=2009CBET.1969....1N | title=Supernova 2009js in NGC 918 | last1=Nakano | first1= S. | last2= Itagaki | first2= K. | last3= Yusa | first3= T. |journal=Central Bureau Electronic Telegrams |issue=1969 |page=1 |year=2009 | url=http://www.cbat.eps.harvard.edu/iau/cbet/001900/CBET001969.txt}}{{cite web | website=Transient Name Server | title=SN{{nbsp}}2009js | url=https://www.wis-tns.org/object/2009js | publisher = IAU | access-date=30 May 2025}}{{Cite web | url = https://apod.nasa.gov/apod/ap091112.html | title = APOD: 2009 November 12 - Art and Science in NGC 918}}{{Cite web | url = https://www.rochesterastronomy.org/sn2009/sn2009js.html | title=Supernova 2009js in NGC 918 | website=www.rochesterastronomy.org}} This was the first subluminous supernova to be studied in infrared wavelengths.{{Cite journal | url = https://ui.adsabs.harvard.edu/abs/2013ApJ...767..166G/abstract | bibcode = 2013ApJ...767..166G | title = SN 2009js at the Crossroads between Normal and Subluminous Type IIP Supernovae: Optical and Mid-infrared Evolution | last1 = Gandhi | first1 = P. | last2 = Yamanaka | first2 = M. | last3 = Tanaka | first3 = M. | last4 = Nozawa |first4 = T. | last5 = Kawabata | first5 = K. S. | last6 = Saviane | first6 = I. | last7 = Maeda | first7 = K. | last8 = Moriya | first8 = T. J. | last9 = Hattori | first9 = T. | last10 = Sasada | first10 = M. | last11 = Itoh | first11 = R. | journal = The Astrophysical Journal | year = 2013 | volume = 767 | issue = 2 | page = 166 | doi = 10.1088/0004-637X/767/2/166 | arxiv = 1303.1565 | s2cid = 54036464}}
  • SN 2011ek (type Ia, mag. 16.4) was discovered by Kōichi Itagaki on Aug. 4, 2011.{{Cite journal|url=https://ui.adsabs.harvard.edu/abs/2011CBET.2783....1N/abstract|bibcode = 2011CBET.2783....1N|title = Supernova 2011ek near NGC 918 = PSN J02254889+1832000|last1 = Nakano|first1 = S.|last2 = Yamaoka|first2 = H.|last3 = Kadota|first3 = K.|last4 = Tsuboi|first4 = M.|last5 = Balam|first5 = D. D.|last6 = Graham|first6 = M. L.|last7 = Hsiao|first7 = E. Y.|last8 = Green|first8 = D. W. E.|journal = Central Bureau Electronic Telegrams|year = 2011|issue = 2783|page = 1}}{{cite web | website=Transient Name Server | title=SN{{nbsp}}2011ek | url=https://www.wis-tns.org/object/2011ek | publisher = IAU | access-date=30 May 2025}}{{Cite web|url=https://www.rochesterastronomy.org/sn2011/sn2011ek.html|title=Supernova 2011ek in NGC 918|website=www.rochesterastronomy.org}}

File:NGC 918 legacy dr10.jpg within our Milky Way with the 10th data release of the Legacy Survey.]]

See also

References

{{reflist}}

External links

  • {{commons category-inline}}

{{WikiSky}}

{{NGC10}}

{{Aries (constellation)}}

{{Catalogs|NGC=918|UGC=1888}}

{{DEFAULTSORT:NGC 918}}

Category:Barred spiral galaxies

Category:Aries (constellation)

918

009236

01888

+03-07-011

02230+1816

Category:Discoveries by John Herschel

18310111

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