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Proposal #474

Proposer (38172) Ariovaldo Siqueira (ari.m.siqueira@icloud.com) obscode: SAMA
Assigned To(3663) Dirk Terrell
Date SubmittedJan. 4, 2024
StatusAllocated
PriorityNormal
Proposal

Dear members of the AAVSOnet Telescope Allocation Committee,

I submit here a proposal for spectral imaging with the BSM Berry telescope, in connection with Proposal #307.

In that proposal, over 600 GR images (SA-200) were taken and these images need additional analyses which will benefit from having spectra taken from at least three of the targets specified below for instrument calibration.

I thank you for your attention to this proposal.

Yours,

Ari Siqueira (SAMA)

Targets
Target RA (H.HH) Dec (D.DD) Magnitude Telescope Observation Frequency Expiration Date Proprietary Term
4 Sgr 17.996543 -23.81611 4.72 BSM_Berry July 16, 2024 No
ksi02 CMa 6.584274 -22.96480 4.5 BSM_Berry July 16, 2024 No
chi Cap 21.142674 -21.19367 5.28 BSM_Berry July 16, 2024 No
ksi01 Sgr 18.955688 -20.65635 5.05 BSM_Berry July 16, 2024 No
eta Crt 11.933598 -17.15082 5.16 BSM_Berry July 16, 2024 No
tet Vir 13.165830 -5.53900 4.4 BSM_Berry July 16, 2024 No

Comments

(38172) Ariovaldo Siqueira — Jan. 4, 2024, 12:56 a.m.

As for the observation frequency, the above targets will require to be imaged only three times each on the same night, for stacking.
Regardless of their brightness, exposure should be on the order of between 10 and 30 seconds for each frame to attain adequate SNR since these will be spectral images, not photometric ones.
Please try to get the best focus on the spectra (first-order diffraction), not the stars (zero-order).
Thank you.

(38172) Ariovaldo Siqueira — Jan. 8, 2024, 1:25 p.m.

Reviewing my comments above, I would like to ask the following, in case this proposal for the imaging of a few A-type stars is approved:
1. That six 30-sec frames be taken for each target;
2. That the camera and grating be positioned horizontally in the North-South direction so that the apparent star displacement occurs perpendicularly to the dispersion line;
3. That the focus receives the fine adjustment needed to prioritize the spectra rather than the star images.
Thank you.

(38172) Ariovaldo Siqueira — Jan. 8, 2024, 7:56 p.m.

I am aware that the targets proposed are not variable stars but to have spectra from such objects with the same gear that generated +600 spectral images in a previous proposal (#307) will be extremely useful for a more complete evaluation of the data already collected at BSM Berry, and for my learning goals.

(3663) Dirk Terrell — Jan. 11, 2024, 4:48 p.m.

The TAC has accepted the proposal. We would like you to check the first set of images for good focus and let Ken know how they look so that we can make adjustments if needed.

(38172) Ariovaldo Siqueira — Jan. 11, 2024, 10:02 p.m.

I am aware of Dirk's last message. I will carefully assess the images' focus. Then I shall inform Ken about my impression of their quality.
Thank you all for the acceptance of this proposal.

(4726) Kenneth Menzies — Jan. 18, 2024, 2:21 p.m.

committed to Berry.

Comments on this proposal are closed.