NGC 638
| NGC 638 | |
|---|---|
 The barred spiral galaxy NGC 638 | |
| Observation data (J2000epoch) | |
| Constellation | Pisces |
| Right ascension | 01h39m37.8s |
| Declination | 07° 14′ 14″ |
| Redshift | +0.010547± 0.000007 |
| Heliocentric radial velocity | 3,162km/s |
| Distance | 42.24 ± 2.97 Mpc (∼138 millionlight-year) |
| Apparent magnitude(V) | 13.8 |
| Apparent magnitude(B) | 14.5 |
| Surface brightness | 12.81 mag/am |
| Characteristics | |
| Type | Barred spiral galaxy |
| Size | 47,200ly(24.48kpc) |
| Apparent size(V) | 0.8' x 0.5' |
| Other designations | |
| PGC6145,Mrk1003, CGCG412-11 | |
NGC 638is a barredspiral galaxylocated in the constellation ofPisces.Its velocity speed to thecosmic microwave backgroundis 2,864± 21 km/s, which corresponds to aHubble's lawof 42.2 ± 3.0Mpc(∼138 millionlight-year).[1]NGC 638 was discovered by American astronomerLewis A. Swiftin 1886.
Only Professor Seligman classifies this galaxy as a barred spiral, and theSDSSsurvey image proves him right.[original research?]
NGC 638 has a broadHydrogen line.NGC 638 is a galaxy whose nucleus shines in the ultraviolet domain. It is listed in theMarkarian catalogueunder the code Mrk 1003 (MK 1003).[2]
To date, two non-redshift measurements give a distance of 55.330 0 ± 1.273Mpc(∼180 millionlight-year),[3]which is outside theHubble distancevalues. Note that theNASA/IPACdatabase calculates the diameter of a galaxy using the average value of independent measurements, when available, and that consequently the diameter of NGC 638 could be about 11.1kpc(∼36,200light-year) if theHubble's lawwere used to calculate it.
NGC 645 Group
[edit]NGC 638 is part of theNGC 645group which includes at least five galaxies. The other three galaxies in this group are NGC 632,UGC1137 andUGC1172.[4]
See also
[edit]Related article
[edit]Other links
[edit]- NGC 638on spider.seds.org
- NGC 638on the LEDA database
- NGC 638on WikiSky
- NGC 638on the site of Professor C. Seligman
References
[edit]- ^"By Name | NASA/IPAC Extragalactic Database".ned.ipac.caltech.edu.Retrieved2024-07-23.
- ^"NGC 638".astrovalleyfield.ca.Retrieved2024-07-23.
- ^"NED Query Results for NGC 638".ned.ipac.caltech.edu.Retrieved2024-07-23.
- ^Garcia, A. M. (1993-07-01)."General study of group membership. II. Determination of nearby groups".Astronomy and Astrophysics Supplement Series.100:47–90.Bibcode:1993A&AS..100...47G.ISSN0365-0138.
External links
[edit]
Media related toNGC 638at Wikimedia Commons
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