Observations of 2MASS J06593158-0405277 needed

[PTS]

AAVSO Alert Notice 518
April 15, 2015

Observations of 2MASS J06593158-0405277 needed

Dr. Fabienne A. Bastien (Hubble Postdoctoral Fellow, Pennsylvania State University) has requested AAVSO assistance in monitoring the rare FU Ori object 2MASS J06593158-0405277 as part of a campaign to observe this T Tauri star from the optical to the infrared in the coming weeks.

Dr. Bastien writes: "Our goal is to obtain detailed outburst light curves and SEDs [spectral energy distributions] of the object before it goes behind the sun at the end of May to help us to place other observations in the context of the outburst. At the moment, only about two dozen of these objects are known, and we have very few constraints on what causes them to undergo their eruptions. This is also one of the brightest such objects that we have seen in recent times (K magnitude of 7.6 and V magnitude of 11.4 as of December 2014).

"...We would like to continue to monitor its behavior from the optical to the infrared (BVRIJHK and/or the equivalent Sloan filters) as it appears to be changing. At least one set of observations per week between now and the end of May would be ideal..."

BVRcIc and visual observations are requested every few nights from now through the end of May. 2MASS J06593158-0405277 is approaching conjunction and in Monoceros is low in the West by the end of astronomical twilight. It will become increasingly difficult to observe, but please keep going as long as possible. The high airmass will not be a problem for the required accuracy of the data - 10% photometry is fine. For the most accurate correlation with the spectroscopic data, it is important that the photometry be transformed.

Coordinates: R.A. 06 59 31.59 Dec. -04 05 27.8 (2000.0)

Charts with a comparison star sequence for 2MASS J06593158-0405277 may be created using the AAVSO Variable Star Plotter (VSP, http::/www.aavso.org/vsp).

Please submit observations to the AAVSO International Database using the name 2MASS J06593158-0405277.

This campaign is being followed on the AAVSO Observing Campaigns page (http://www.aavso.org/observing-campaigns).


This AAVSO Alert Notice was compiled by Elizabeth O. Waagen.

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This sounds great -- 10% photometry is fine, and we would be happy to also
have visual observations. We suspect the object may be brightening, so any
additional observations would be very helpful. I will create an AAVSO account today.

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but it will become a
tough target after the end of April. She is able to use visual data though,
so it should be a fairly broad campaign.

at best -- by the time astronomical twilight ends today it's already at airmass of 2.
It's certainly still observable, but data quality may not be ideal. What are your useful
uncertainty limits? Ten percent photometry will be straightforward, but one or two
percent may not be.

If it is still close to V=11-12 it should be ok; unless B-V is more than 2 then B will
also be doable. We do have observers who can do very bright stars at J and H, but their
faint limits are magnitude 4 or 5, and K is not possible with the diode photometers they
use. We will ask for BVRcIc; can you make use of visual observations for this? They
are typically good to about 10 percent (0.1 magnitude) and track Johnson V
reasonably well.