ToO Information

Request ID: 38795
Request Type: NEW
ToO Urgency: WITHIN A WEEK
Proposal ID: 3058

Target Info

Target Name: GX 339-4
Target No.: 6365
Category: X-RAY BINARIES
Coordinates[J2000]: (255.70575, -48.78976)
Exp (ks): 60
Extended: N

Extent Size:

Background Restriction: N

Remarks:

Constraint Details

Monitor: Y

Criteria: We request the observing time to be split into 15 observations each 4 ks long, to cover the luminous hard state, (possible) hard-to-soft transition, and the decay back to the hard state, preferably 5 observations in each stage. Considering the unpredictable evolving timescale of black hole transients (especially if the source does a state transition), a two-day cadence is preferred.

Phase Dependent: N

Epoch:
Period:
Min:
Max:
Remarks:

Specific Time: Y

Start: 2021-02-13 00:00 UTC
End: 2021-03-15 00:00 UTC
Remarks: NICER already has this target in planned schedule until 2021-02-12 on a daily cadence, so we can trigger our GO program from 2021-02-13, with a two-day cadence and a 4 ks exposure. NICER ToO on 2021-02-04 has reached count rate of 500 counts/s, in 9 days, it is very promising to reach our GO program triggering criteria of 1000 counts/s (a power-law trend of count rate predicts ~800 counts/s).

ToO: Y
Coordinate Observation: Y

Observatory: NuSTAR
Description: Members of our team requested and were approved NuSTAR DDT, so NuSTAR is likely to be carrying out several observations of GX 339-4 in the same timeframe as our campaign. We request, when possible, that NICER tries to achieve some overlapping coverage given the complementary nature of the instruments which is beneficial for both spectral and timing analysis.

Uninterrupted: N

Justification:

Estimated Count Rate (cts s-1): 1000.000

Requester Information

Name: MS. JINGYI WANG

Status

Request Date (UTC): 2021-02-05 17:46:07
Disposition: GO-preapproved

Date: 2022-01-13 22:19:16.633419
Reason:
Person:

Status: Complete

Date: 2022-01-13 22:19:16.633419
Person:

Misc

Note: 15 4ks observations every 2 days to cover the luminous hard state, (possible) hard-to-soft transition, and the decay back to the hard state

Target Details

Nearest Target No:
Nearest Taget Name:
Separation (arcmin):
Nearby Target (<3.0'):
Referenced Target Catalogue:
Sun Angle: No Data

Planned Observations

AGS6 Reference:
Planned Snapshots:

Observation Start	Observation End	Span	Mode	Observation ID
(YYYY-DDDTHH:MM:SS)	(YYYY-DDDTHH:MM:SS)	(seconds)	Man/Opt

Visibility

AGS3 Reference:
Visibility Report:

Target Name	Target ID	Visibility Start	Visibility End	Span	Initial	Final	Relative
		(YYYY-DDDTHH:MM:SS)	(YYYY-DDDTHH:MM:SS)	(seconds)	Interference	Interference	Orbits