By Catherine Lovekin (on behalf of the Canadian BRITE team)
(Cassiopeia – Autumn / l’automne 2021)
BRITE-Constellation is an international space astronomy mission consisting of a fleet of 20x20x20 cm nanosatellites dedicated to precision optical photometry of bright stars in two photometric colours. The mission continues in full science operations, with 38 datasets available in the public domain from the BRITE public archive. As of April of 2020, all data is made public as soon as decorrelation is complete, with no proprietary period.
The BRITE mission is a collaboration between Canadian, Austrian and Polish astronomers and space scientists. The Canadian partners represent University of Toronto, Université de Montréal, Mount Allison University, and Royal Military College of Canada. The mission was built, and the Canadian satellites operated by, the University of Toronto Institute for Aerospace Studies Space Flight Lab (UTIAS-SFL). The Canadian Space Agency funded the construction of the Canadian satellites, and continues to support their day-to-day operations.
There are five BRITE satellites in the Constellation, which work together to obtain well-sampled, long term continuous (~6 months) light curves in both red and blue band passes across a variety of sky fields.
As this issue of Cassiopeia went to press, the assignments of the BRITE nanosats was:
- BRITE Toronto (Canada): This satellite observes with a red filter. It is currently observing the Cygnus field for the fourth time.
- BRITE Lem (Poland): Lem observes with a blue filter, but is currently idle due to unresolved stability issues.
- BRITE Heweliusz (Poland): Heweliusz observes with a red filter. It is also currently observing the Cygnus field, although has been having some problems with fine pointing. Alternate fields are being considered.
- BRITE Austria (Austria): BRITE Austria observes with a red filter. It is currently observing in Sagittarius and Orion, revisiting the fields for the seventh and eighth times respectively.
- UniBRITE (Austria): Currently out of order.
The BRITE Constellation observing program is currently set through late 2021. Details of the observing plan will be available on the BRITE photometry Wiki page.
Recent Science Results
This paper reports on results of an analysis of the BRITE-Constellation and Solar Mass Ejection Imager photometry and radial-velocity observations, archival and new, of two single-lined spectroscopic binary (SB) systems ν Centauri and γ Lupi. In the case of γ Lup AB, a visual binary, an examination of the light-time effect shows that component A is the SB. Both ν Cen and γ Lup exhibit light variations with the orbital period. The variations are caused by the reflection effect, i.e. heating of the secondary’s hemisphere by the early-B main sequence (MS) primary component’s light. The modelling of the light curves augmented with the fundamental parameters of the primary components obtained from the literature photometric data and Hipparcos parallaxes, shows that the secondary components are pre-MS stars, in the process of contracting on to the MS. ν Cen and γ Lup A are thus found to be non-eclipsing counterparts of the B2 IV eclipsing binary (and a β Cephei variable) 16 (EN) Lac, the B5 IV eclipsing binary (and an SPB variable) μ Eri, and the recently discovered Large Magellanic Cloud nascent eclipsing binaries.
Conferences, Resources, and Social Media
The BRITE team does not plan to host any conferences this year.
Resources and Social Media
The BRITE Public Data Archive, based in Warsaw, Poland, at the Nikolaus Copernicus Astronomical Centre, can be accessed here.
The mission Wiki (including information on past, current and future fields) can be accessed here.
BRITE Constellation is on Facebook, at @briteconstellation.
The BRITE International Advisory Science Team
The BRITE International Advisory Science Team (BIAST), which consists of BRITE scientific PIs, technical authorities, amateur astronomers, and mission fans, advises the mission executive on scientific and outreach aspects of the mission. If you’re interested in joining BIAST, contact Konstanze Zwintz, the chair of BEST.