This short report describes some highlights in extragalactic research over the past three years, and lists the main symposia and meetings in the domain.

The Supernova Working Group was re-established at the IAU XXV General Assembly in Sydney, 21 July 2003, sponsored by Commissions 28 (Galaxies) and 47 (Cosmology). Here we report on some of its activities since 2005.

The members of Commission 28 on Galaxies were very busy during this General Assembly, with the Commission involved in two Symposia (IAU Symposium No. 235 Galaxy Evolution across the Hubble Time, IAU Symposium No. 238 Black Holes: from Stars to Galaxies), and two Joint Discussions (JD07 The Universe at z > 6, JD15 New Cosmology Results from the Spitzer Space Telescope). Therefore, the Business Meeting was combined with the Division VIII Business Meeting, which included a short information session on the new Commission 28 Organizing Committee. The triennial report of the Commission for 2003-2005 was also distributed, and is available on the Commission 28 web site.

Using simple physical assumptions we derived fundamental parameters including: the mass of synthesised 56Ni, the ejecta mass, and the explosion energy of Type Ia supernovae. The methods have been described in several recent publications and comparison with other methods shows general consistency.

Light curves are the most readily available and most frequently used astrophysical tools for variable phenomena. Supernovae are no exception to this. The information that can be extracted from detailed light and colors curves, together with the detailed study of the spectral evolution, tells us about the progenitor star, the various energy input sources, the explosion environment, material in the line of sight and cosmological effects. Over the past decade we have come to understand the power of detailed light curve studies and how they tie into the exploration of other astrophysical topics.

The present understanding of type Ib/c supernovae and their connection to interacting binaries is reviewed. The problems of the classification and the lack of well-observed events exclude direct inference of progenitor characteristics. The absence of hydrogen lines in the observed spectrum, nevertheless, requires restricted evolutionary schemes to produce suitable progenitor stars for core collapse explosions with no hydrogen envelope. New relative statistics among the supernova types are presented which indicate that SN Ib/c are on average brighter than SN II, and with the dense sampling of supernova searches in nearby galaxies, a small intrinsic incidence of SN Ib/c is determined. The small rates might be in conflict with the observed ratio of massive stars in binaries in the Galaxy.

Although emerging from a range of progenitor stars and the product of different explosion mechanisms the light curves of the various supernova types are shaped mainly by radioactive power. Core-collapse supernovae have in addition early peaks from shock breakout with a subsequent cooling phase and massive extended stars a recombination (plateau) phase. Variations occur mostly due to differences of the progenitor stars. While there appears to be a fair understanding of the light curves of SNell, new wrinkles are emerging for SNela. The photometry of SNe lb and SNe Ic remains unsatisfactory.