Cosmic Origins Spectrograph Instrument Handbook for Cycle 17

11.3 Get the Tools and Rules

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As with Phase I, there are two essential software tools you will need:

• APT, the Astronomer's Proposal Tool, and
• The COS Exposure Time Calculator (ETC).

For this first cycle of COS usage, there are no previously executed programs whose data you can examine, but the ETC includes a number of examples of many different kinds of celestial objects as reference points, or you can use an existing spectrum of your own or from the HST archive as a starting point.

In addition, you will need the Phase II Proposal Instructions to refer to to ensure your syntax and usage are correct.