Professor Horst Cerjak, 19.12.20051

BRITE 2014

W.Weiss, R.KuschnigUniversity of Vienna

BRITE Constellation – 2 Years in Orbit

O. Koudelka, M.Unterberger, P.Romano Graz University of Technology

Professor Horst Cerjak, 19.12.20052

BRITE 2014

Contents

• Scientific Goals• Mission Description• Operations• Scientific Data Collection and Analysis• Summary

Professor Horst Cerjak, 19.12.20053

BRITE 2014

• First nanosatellite constellation dedicated to an astronomy mission (astereoseismology)

• 5 spacecraft operational in Space• Austria (BRITE-Austria/TUGSAT-1 & UniBRITE)• Poland (BRITE-PL1 „Lem“ & BRITE-PL2 „Heveliusz“)• Canada (BRITE-CAN1 „Toronto“)

BRITE (BRIght Target Explorer)

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BRITE 2014

Scientific Goals• Photometric measurement of brightness and

temperature variations of massive luminous stars (up to visual magnitude 4)

• Fastest data cadence: few minutes

• Time base: up to 2 years

• high duty cycle

• 2-colour (blue and red)

• 24° field of view

Professor Horst Cerjak, 19.12.20055

BRITE 2014

BRITE Flight Model

telescope

star tracker

solar cells

magnetometer

S-band antenna

Size: 20 x 20 x 20 cm

Mass: 6.8 kg

Power: 6…10 W

S-Band downlink (256 kbit/s)

UHF uplink (9.6 kbit/s)

Professor Horst Cerjak, 19.12.20056

BRITE 2014

Launch

• TUGSAT-1/BRITE-Austria andUniBRITE were launched byPSLV-C20 of ISRO/ANTRIX on 25 February 2013from the Satish DhawanSpace Centre in Sriharikota

• Sun-synchonous LEO orbit

Courtesy: ISRO

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Mission Operations

• 14 orbits per day • 3 orbits in morning sequence• 3 - 4 orbits in evening sequence

• Automatic & remote ground stations operations supported

• BRITE-Austria operated from Graz• UniBRITE operated from Toronto

Professor Horst Cerjak, 19.12.20058

BRITE 2014

Management

• BRITE Executive Science Team (BEST)�Scientists from Austria, Canada, Poland�Defines targets

• Operation teams�Prepare commands for spacecraft, �up- and downloads

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BRITE 2014

Satellite Performance

• RMS pointing stability in X / Y: 1.6 / 1.5 pixels (2 – 3 pixels)

• Up to 20 subrasters: 32x32 to 24x24 pixels

• Typical 1 sec integrations, stacking available

• CCD deterioration due to radiation -> chopping

Attitude Spacecraft temperature

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Raster Photometry

• Raster: 24 x 24 pixels

All 15 rasters during one observation, spacecraft pointing at Orion

Professor Horst Cerjak, 19.12.200511

BRITE 2014

Ultrapraecision

from ground in space

11

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BRITE 2014

Observations Planning

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BRITE 2014

Life Cycle of MatterLife Cycle of Matter

White DwarfsNeutron StarsBlack Holes

Professor Horst Cerjak, 19.12.200514

BRITE 2014

Light Curve for Orion

Gray curve: TUGSAT-1/BRITE-Austria (blue filter)Bllue curve: UniBRITE (red filter)

Professor Horst Cerjak, 19.12.200515

BRITE 2014

Bright Star Bonus� Interferometry

• angular diameter

� Adaptive Optics & Lucky Image

• stellar & debris disks

� Parallax with high accuracy

• linear diameter

� Very high spectral resolution spectroscopy

• stellar fundamental parameters & atmosphere

• (Doppler) surface imaging

� Time resolved spectroscopy

• asteroseismology

� Spectropolarimetry

• magnetic field structures

� Multi-wavelengths options

� ““““Easy”””” access to telescope time

of medium size telescopes

Professor Horst Cerjak, 19.12.200516

BRITE 2014

Summary

• BRITE-Constellation is the world‘s first nanosatellite constellation dedicated to astronomy

• 5 components of BRITE-Constellation operational

• Scientific & technical requirements fully met

• Science fields: 150d in Orion, Centaurus, Perseus, and Vela Pupis.

• Observing program developed till end 2016

• Scientific data analysis under way

Professor Horst Cerjak, 19.12.200517

BRITE 2014

Professor Horst Cerjak, 19.12.200518

BRITE 2014

Thank you for your attention!