Chandra X-ray Center

Chandra Cycle 28 Call for Proposals Released 18 December 2025

The CXC is pleased to announce the release of the Chandra Cycle 28 Call for Proposals (CfP). The Call for Proposals, Proposers' Observatory Guide (POG), proposal planning software, and general information are posted on the "Proposer" web page.

Proposals are due:
Wednesday, 18 March 2026 at 6PM (US Eastern Daylight Time)

For more information, see the full announcement.

12/18/25

CIAO 4.18, Sherpa 4.18, CALDB 4.12.3, SAOImageDS9 8.7b2, and MARX 6.0.1 Released

The Chandra X-ray Center (CXC) is pleased to announce the release of the following new software packages:
CIAO 4.18
Sherpa 4.18
CALDB 4.12.3
SAOImageDS9 v8.7b2
MARX 6.0.1

For more information, see the full announcement.

12/16/25

HRC Anomaly Notice

On the evening of October 24th during a real time contact in which the HRC-S was scheduled to be observing V1935 Cen, the HRC team noted that the HRC-S High Voltage Power Supply was OFF, when it should have been ON. This anomalous detector state led the team, in consultation with the Flight Director and Lead Systems Engineer, to manually command the HRC into a safe state. All other spacecraft and detector telemetry appeared nominal at the time. The HRC remains inactive while the instrument and operations teams diagnose the issue.

11/4/25

Chandra Cycle 28 Call for Proposals Released 18 December 2025

CIAO 4.18, Sherpa 4.18, CALDB 4.12.3, SAOImageDS9 8.7b2, and MARX 6.0.1 Released

HRC Anomaly Notice

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