NASA's James Webb Space Telescope

March 5th Social Media Q&A Session on Twitter

News Feature March 9, 2018

Promotional image for March 5, 2018 Q&A session.

STScI held a Question & Answer session on our JWST Observer Twitter account on Monday, March 5, 2018. Below are the questions and answers from that session.

Q. In the MSA catalog input tool, can we input strings as IDs or must they be integers?

A. The developers confirmed that the input must be integers.

Q. Figuring out the optimal TA target now seems pretty time intensive. Do I need to worry about that now? Or, can I just set it to some typical set up for WATA target acq and include a note that the target will be decided later? I want to use the IFU on NIRSpec for a galaxy and will likely use WATA target acq. for the observations. The galaxy is too extended to use as the TA target, so I'll probably need to pick a nearby star.

A. The expectation is that submitted proposals would be executable.

Q. The visit planner is taking forever to run for my solar system observation in APT. What gives?

A. The visit planner no longer takes forever to run in APT 25.4.3 because guide star checking has been turned off for solar system observations.

Q. Will Trappist-1 be somewhere on the list of "somewhere to look for life?" There could be life on one of the many planets of that star?

A. The TRAPPIST-1 system is among the first things the James Webb Space Telescope will look at. JWST won't search for life, but will characterize exoplanet atmospheres. Learn more by reviewing the GTO Program 1331 and at

Q. When getting NIRSpec IFU observations, what's the plan for Leak Calibrations? Several ERS proposals only take one Leak Cal per dataset (i.e. one Leak Cal for 12 G235H/F170LP exposures), where I figured it should be one cal per dithered exposure?

A. Here is a JDox article that discusses recommended strategies for dealing with NIRSpec MSA leakage.

Q. Are targets protected or modes? E.g. all have favorite objects in favorite deep fields. Can we “all” observe with the same mode/filter/instrument on a pointing, but different shutters opened or closed based on our preferences without duplication/protection concern?

A. You can refer to the JDox article on the Duplicate Observations Policy. The NIRSpec MSA case is nuanced so if you have additional questions, you should reach out to the JWST Science Policy Help Desk.