NGC 4017 is an intermediate spiral

radio galaxy A radio galaxy is a galaxy with giant regions of radio emission extending well beyond its visible structure. These energetic radio lobes are powered by jets from its active galactic nucleus. They have luminosities up to 1039 W at radio wav ...

located in the constellation Coma Berenices. Its speed relative to the

cosmic microwave background The cosmic microwave background (CMB, CMBR), or relic radiation, is microwave radiation that fills all space in the observable universe. With a standard optical telescope, the background space between stars and galaxies is almost completely dar ...

is 3,748 ± 21 km/s, which corresponds to a Hubble distance of 55.3 ± 3.9 Mpc (~180 million ly). NGC 4017 was discovered by German-British astronomer William Herschel in 1785. It is difficult to see a bar in the center of NGC 4017 in the image obtained from the SDSS survey data. The intermediate spiral classification from the NASA/IPAC database seems to fit this galaxy better. The

luminosity class In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction gratin ...

of NGC 4017 is II-III and it has a broad HI line. To date, four non-redshift measurements yield a distance of 73.850 ± 14.580 Mpc (~241 million ly), which is just outside the Hubble distance values. Note, however, that it is with the average value of independent measurements, when they exist, that the NASA/IPAC database calculates the diameter of a galaxy and that consequently the diameter of NGC 4017 could be approximately 29.3 kpc (~95,600 ly) if we used the Hubble distance to calculate it.

Supernovae

Two supernovae have been discovered in NGC 4017: SN 2006st and SN 2007an.

SN 2006st

This supernova was discovered on May 30, 2006 by D. Winslow and W. Li as part of the LOSS (Lick Observatory Supernova Search) program at the Lick Observatory. This supernova was type II.

SN 2007an

This supernova was discovered on March 10, 2007, by Marco Migliardi in an image taken at the Drusci observatory in the Italian town of

Cortina d'Ampezzo Cortina d'Ampezzo (; , ; historical ) sometimes abbreviated to simply Cortina, is a town and ''comune'' in the heart of the southern (Dolomites, Dolomitic) Alps in the province of Belluno, in the Veneto region of Northern Italy. Situated on the ...

. This supernova was type II.

NGC 4017 Group

According to A.M. Garcia, the galaxy NGC 4017 is part of a group of galaxies that bears his name. The NGC 4017 group has four members. The other members of the group are NGC 4004, NGC 4008 and NGC 4016. Abraham Mahtessian also mentions a group of which NGC 4008 is a part, but there are only three galaxies in his list, NGC 4017 not appearing there. On the other hand, it is surprising that the galaxy IC 2982 to the west of NGC 4004 does not appear in either list. The distance separating it from the Milky Way is 53.86 ± 3.78 Mpc (~176 million ly), practically the same as that of NGC 4004. This galaxy is even designated as NGC 4004B by the database NASA/IPAC We could even say that the two galaxies form an interacting pair given the deformation of NGC 4004. This is undoubtedly why the two galaxies are included in the catalog of Vorontsov-Velyaminov interacting galaxies. The galaxies NGC 4016 and NGC 4017 are almost the same distance from the Milky Way and are neighbors in the celestial sphere. The image obtained from the SDSS study data shows a certain deformation in the galaxy NGC 4016. These two galaxies are surely in gravitational interaction and they also appear in the catalog of Vorontsov-Velyaminov interacting galaxies. They also appear in Halton Arp's ''

Atlas of Peculiar Galaxies The ''Atlas of Peculiar Galaxies'' is a Astronomical catalog, catalog of peculiar galaxies produced by Halton Arp in 1966. A total of 338 galaxies are presented in the atlas, which was originally published in 1966 by the California Institut ...

'' under the designation Arp 305.

Halton Arp Halton Christian "Chip" Arp (March 21, 1927 – December 28, 2013) was an American astronomer. He is remembered for his 1966 book ''Atlas of Peculiar Galaxies'', which catalogued unusual-looking galaxies and presented their images. Arp was als ...

notes that one of the arms of NGC 4016 has a broken segment.

External links

NGC 4017
at NASA/IPAC
NGC 4017
at

SIMBAD SIMBAD (the Set of Identifications, Measurements and Bibliography for Astronomical Data) is an astronomy, astronomical database of objects beyond the Solar System. It is maintained by the Centre de données astronomiques de Strasbourg (CDS), Fr ...

NGC 4017
at LEDA

References