AAVSO: American Association of Variable Star Observers

Proposal #236

Proposer (4848) George Silvis (gasilvis@gmail.com) obscode: SGEO
Assigned To(3663) Dirk Terrell
Date SubmittedNov. 10, 2021

Kepler-167 e is due to transit 11/18-19. It has a long period (1071 days) so this is a rare event with a lot of interest from the exoplanet community.
The transit time is some 16.4 hrs, so no site can get the whole thing. But the US East coast can capture the egress.
I propose that NH2 and TX be tasked to capture the egress on the 19th. They would observe in R, as there will be a full moon, and run from dusk to 2200 EST. About 5 hrs
If NH2 had good weather and was started I could cancel the run on TX, but the more data the merrier.
I would also need some shots prior to 11/19 to set exposure, with the goal to be near snr 200. V is 14.3 with V-R= 0.501, so R would be 13.8

Target RA (H.HH) Dec (D.DD) Magnitude Telescope Observation Frequency Expiration Date Proprietary Term
Kepler-167 19.510556 38.34528 14.5–14.3 BSM_NH2 once May 12, 2022 No


(3663) Dirk Terrell — Nov. 12, 2021, 5:53 p.m.

Comments from Arne:

This is a time critical proposal. Certainly NM or TX could handle the western US part of the transit. NH2 could observe the beginning hour or two before the target gets too far west and into the trees. A test run would show how far west we could observe. That said, one concern is the R filter. We do have Sloan r', but there has been some question as to whether the existing R filter in the filter wheel is Cousins R or tricolor R. I can pull it and see what I can find out. Or, perhaps Sloan r' will be acceptable. If I could get some help working on Hamren and its joysticking issues, there is a possibility that we could get the Hawaian longitude.

R=13.8 with SNR=200 is a non-trivial observation. There are a couple of fainter neighbors to the east at about 10-15arcsec, meaning that they would be very near the edge of a measuring aperture. You would need to take special care in avoiding them. SNR200 would mean exposures around 5 minutes, though that can be checked with the test images. With the long transit, the long exposures are probably ok.

(4726) Kenneth Menzies — Nov. 13, 2021, 10:51 p.m.

Committed to NH2. Test run soon. Check exposure. Now at 240s.

Run set for 11/18-19

Too faint for TX? I put it there as well for test. 300s.


(2108) Arne Henden — Nov. 14, 2021, 10:55 a.m.

It looks like Tuesday night 11/16-17 might be good enough for the test exposures at NH2. However, current forecast is for clouds/rain/snow on 11/18-19. Conditions may change, but I'd consider NH2 chances as being low.

(4848) George Silvis — Nov. 16, 2021, 3:53 p.m.

I've adjusted the plan timings. Egress is 11/19 2323 UTC to 11/20 0118 UTC.
NH2 might get 3rd contact, TX 4th contact.

(4848) George Silvis — Nov. 17, 2021, 6:59 p.m.

I've also added the plan to BSM_NM in the hope of getting the 4th contact.

(4848) George Silvis — Nov. 20, 2021, 2:26 p.m.

Alas, no observations taken. NH2 and TX did not run last night and NM failed and rejected the plan.

The plan has been taken off the scopes and archived. Next chance to two years away.


Comments on this proposal are closed.