Fermi Gamma-ray Space Telescope

Fermi ToO 070603-1-1

A ToO observation to observe NOVA SGR 2015 NO.2 at RA, Dec = 274.2375, -13.9283 (J2000) was approved at 2015-03-19 22:57:49 UTC.

The justification for the ToO is: Fermi TOO on N Sgr 2015 no.2 commenced Mar 17.9 UT resulting in ~2x increased exposure while preserving all-sky coverage. The initial report of very-rapid optical brightening to 5.3 mag 0.1d after 6.0 mag discovery, and inferred fast fading (our original motivation to start Fermi ToO ASAP after discovery) is not confirmed. Instead optical still brightening, currently 5.0 mag @3d post discovery, decline expected in coming days when ToO scheduled end Mar 22.9. Continuation of ToO for 1 week will detail sudden rise in g-rays expected -2d after optical peak based on previous LAT detections of naked-eye novae giving increased temporal coverage and statistics for spectral analysis while g-ray bright. If non-detected, ToO achieves 1d flux limits 3-6x lower than observed peaks of comparable novae.

The planned duration is 605.00 ks.

The autonomous request threshold during this ToO is LOW.

The ToO observation should begin between 2015-03-22 00:00:00 UTC and 2015-03-29 00:00:00 UTC.

The ToO observation was requested by DR. CHI (TEDDY) C CHEUNG.

Exposure Map for Week 355

Exposure Map
  • Energy Band: 100.00 MeV to 200000.00 MeV
  • The ToO is inserted in the Mission Week 355 timeline from 2015-078-00:00:00 to 2015-081-00:00:00.
  • Exposure is 1.6699e+09 cm^2 s^1 at the ToO location (RA=279.2375, dec=-28.9283)
  • Orbit latitude of the pointing is -51.1094 degrees