Spiral Galaxy NGC 772; Elliptical Galaxy NGC 770

aka Arp 78
Supernovae 2003hl & 2003iq

Image taken on Nov.16, 2003.

Image taken on Dec. 28, 2003.

Supernova 2003hl:

• Discovered: August 20, 2003, by University of California at Berkeley's Katzman Automatic Imaging Telescope (LOTOSS).
• Magnitude 16.5 at discovery.
• Type: II

Supernova 2003iq:

• Discovered: October 8th, 2003, by French amateur astronomer Jean-Marie Llapasset.
• Magnitude 15.9 at discovery.
• Type II
• T. Matheson, P. Challis, and R. Kirshner, Harvard-Smithsonian Center for Astrophysics, report that a spectrum taken with the Mt. Hopkins 1.5-m telescope show that SN 2003 iq a type-II supernova with a very blue continuum with P-Cyg lines of hydrogen and helium with an expansion velocity of 10,500 km/s.

Follow this Link to a NASA Web site on supernovas. It has a very nice animation and a description of what these objects are.

Galaxies NGC 770 & 772, Arp 78:

Spiral Galaxy NGC 772 and Elliptical Galaxy NGC 770, aka Arp 78, are a physically close pair of galaxies in the Constellation of Aries.

NGC 772, the host of Supernovae 2003 hl and 2003 iq, is a Spiral Galaxy with a small, very bright, diffuse nucleus. It has many weak, tightly coiled arms, one abnormally strong. The arms, although well formed, are relatively smooth, indicating only a small current rate of star formation except in the single high-surface-brightness arm which contains several evident HII regions. The relatively smooth multiple arms on the opposite side from the prominent arm are defined primarily by the fragments of spiral dust lanes. This galaxy is also know as Arp 78 and is in Arp's class `small, high surface brightness companions'. Apparent companion galaxies at 4.1 and 5.7 arc minutes may be extremely diffuse plumes that are parts of NGC 772; `faint material toward each of the two dwarf companions' (Arp). These objects have anomalous redshifts (Astrophys. Letters 5, pp 257-260).

NGC 770 appears to be an Elliptical Galaxy that is at about the same distance as NGC 772, and is a companion of the larger spiral system.

A rough distance estimate of this galaxy pair, and the two supernovae, is 130 million light years.

NGC 772 Magnitude: 11.0 Constellation: Aries RA: 01h 59m 20.3s Dec: +19° 00' 22" Epoch 2000 Size (mins): 7.3' x 4.3' Classification: SA(s)b        Spiral Galaxy, S-shaped Dreyer description in the NGC:        "Bright, considerably large, round, gradually brighter middle, resolvable, but mottled."

NGC 770 Magnitude: 13.9 Constellation: Aries RA: 01h 59m 13.2s Dec: +18° 57' 18" Epoch 2000 Size (mins): 1.2' x 0.8' Classification: E3:        Elliptical Galaxy (uncertain) Dreyer description in the NGC:        Very faint, small, round, southwest NGC 772.

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George Normandin, KAS

November 23rd, 2003
Revised: December 31, 2003