Main Proposer Page

What's New in Cycle 24

Section references in this document are for the most recent CfP

Change in exclusive use period

The exclusive use (proprietary) period will be six months for GO, TOO, LP and GTO proposals in Cycle 24 and subsequent cycles. See Section 3.2 and Section 3.3 of the CfP for further details.

Referencing for dual anonymous peer review

References must be written in the form of a number in a square bracket, e.g. [1], which will then correspond to the full citation in the reference list.

Split Observations and Overlapping Cycles

There are significant restrictions on the duration of Chandra observations at many solar pitch angles (see POG Section 3.3). Consequences of these restrictions include:

  1. It can take up to two years to fully complete an observing cycle, with a roughly 1 year overlap between cycles. Priority is given to observations from earlier cycles, but sometimes unconstrained observations can be scheduled up to two years after the nominal start of a cycle.

  2. Longer observations are being split into smaller segments. Proposers should be aware that this trend will continue in Cycle 24 and beyond, with segment durations in the range 10-20 ks expected. Segments may be separated by months and in extreme cases up to two years. Two new constraints are available in Cycle 24 to manage scheduling of split segments:
    • A new flag for phase constrained observations: do unique parts of the phase need to be covered if the observation is split? I.e., do the deferred segments need to be placed in different phase windows than the previously scheduled segments? See Section 4.4 of the CfP for more details
    • A new constraint to specify completion time: if this observation is split, all the segments must be completed within a specified number of days. See Section 4.4 of the CfP for more details.

Allocation of RC and HEL time to Joint Partner Observatories

Observatories that allocate Chandra time as part of our Joint Time agreements will be given an allocation of Resource Costs points and time at High Ecliptic Latitude. Highly ranked proposals from our Joint Time partners may not ultimately be accepted if HEL time or RC limits are exceeded.

Web based RC calculator

A new web-based RC calculator is expected to be released in early 2022. See