Fermi Gamma-ray Space Telescope

Fermi ToO 070602-1-1

A ToO observation to observe NOVA SGR 2015 NO.2 at RA, Dec = 274.2375, -13.9283 (J2000) was approved at 2015-03-17 14:47:50 UTC.

The justification for the ToO is: Discovered at 6.0 mag Mar 15.634 UT, incoming reports of classical nova N Sgr 2015 no.2 (AAVSO alert 512) indicate rapid rise to naked-eye peak mag 5.3 (Mar 15.802), and declining to 15.8-6.1 mag on Mar 16 (today), i.e. in early optically thick fireball stage. If similar to other optically bright classical novae, N Del 2013 and Cen 2013, LAT g-ray >100 MeV detections with fluxes (0.3-1)E-6 ph/cm2/s are expected beginning 1-2 days after optical peak. The origin and site of novae g-ray emission is still unclear and 5-day Fermi ToO ensures sufficient exposure to probe similar flux levels of previous LAT detected novae at similar stage. N Cen showed optical and g-ray rebrightening 9-days after first optical peak, so request for continuation past 5 days conditional on N Sgr optical evolution.

The planned duration is 432.00 ks.

The autonomous request threshold during this ToO is LOW.

The ToO observation should begin between 2015-03-17 14:47:49 UTC and 2015-03-24 14:47:49 UTC.

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

Exposure Map for Week 354

Exposure Map
  • Energy Band: 100.00 MeV to 200000.00 MeV
  • The ToO is inserted in the Mission Week 354 timeline from 2015-076-00:00:00 to 2015-078-00:00:00.
  • Exposure is 1.4274e+09 cm^2 s^1 at the ToO location (RA=279.2375, dec=-28.9283)
  • Orbit latitude of the pointing is -51.7634 degrees

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