Proposal #189
| Proposer | (38606) Gabriel Neagu (gabrielneagu874@gmail.com) obscode: NGCA |
|---|---|
| Assigned To | (3663) Dirk Terrell |
| Date Submitted | Feb. 4, 2021 |
| Status | Declined |
| Priority | Normal |
| Proposal | Hi This is a variable star i recently found. It's not yet in VSX, but i submitted it. It is surrounded by nebulosity, but the nebulosity isn't observed in DSS, but only in DECaPS images. From 2010 to 2019, a huge brightening in WISE images happened. The problem is that ASAS-SN didn't observe this star since about 2017. It might be anywhere from 19.8 r (derived from DSS images) and 15.2 V (ASAS-SN). Can i get some data on it? From the looks of it, it might be a variable star in a variable nebula. The DECaPS images also show a shockwave-like feature in the nebula. |
| Target | RA (H.HH) | Dec (D.DD) | Magnitude | Telescope | Observation Frequency | Expiration Date | Proprietary Term |
|---|---|---|---|---|---|---|---|
| NGCA-V84 | 7.987575 | -31.14571 | 16.7–15.2 | — | — | — | No |
Comments
- (3663) Dirk Terrell — Feb. 4, 2021, 6:28 p.m.
Can you give us some more information on the variability, like the timescale of the variability? We need to have some idea of what you're looking for. Do you need a week of data? A month? Several years?
- (3663) Dirk Terrell — Feb. 4, 2021, 6:33 p.m.
Please read (or re-read) the how-to document at https://www.aavso.org/how-write-aavsonet-proposal
It contains valuable information on writing observing proposals.
- (38606) Gabriel Neagu — Feb. 5, 2021, 7:19 p.m.
I got some data on it placing it at about 18 R. I would need data in z or y filters to see if there are any recent changes in the nebula. The I-band observations seem to show that the nebula somehow got very dim. The first ASAS-SN data is in August 2016 and since then, until January 2017 it dimmed until it became invisible. Since then, we have no data on this star. I think some y or z-band observations to show the nebula would be enough and some observations to determine the color of the main star.
- (3000) Sebastián Otero — Feb. 5, 2021, 7:46 p.m.
Gabriel, I am reviewing your VSX submission. I agree it may have had en EXOR-like outburst in 2016, but if it did, that is now over and back to V= 21-22 mag; i ~19.2, r ~20, y ~18.7.
So I don't think that observations right now can be successful. And if so, if the star is not in outburst, what do you expect to find? VPHAS+ DR2 data already give us colour information and there are 2MASS and WISE colours too. The star is also an IRAS source. There is infrared excess and it is very likely a YSO.
I don't think this is a suitable object to follow.- (38606) Gabriel Neagu — Feb. 6, 2021, 6:56 p.m.
Hi, I recently got some follow-up from New Mexico, showing the star at about 18.3 R. Got some observations scheduled from the INT (spectra) that could come in the next 2 weeks. What could be needed to confirm it as an EXOR and to remove the uncertainty?
- (38606) Gabriel Neagu — April 17, 2021, 11:36 a.m.
After the analysis in collaboration with some researchers, we concluded it's not an YSO and decided to look for more outbursts. Is it possible to get an image per week on the target in red filters? R, I and redder are reccomended.
Comments on this proposal are closed.