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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 therare FU Ori object 2MASS J06593158-0405277 as part of a campaign to observethis T Tauri star from the optical to the infrared in the coming weeks.
Dr. Bastien writes: "Our goal is to obtain detailedoutburst light curves and SEDs [spectral energy distributions] of the objectbefore it goes behind the sun at the end of May to help us to place otherobservations in the context of the outburst. At the moment, only about twodozen of these objects are known, and we have very few constraints on whatcauses them to undergo their eruptions. This is also one of the brightest suchobjects that we have seen in recent times (K magnitude of 7.6 and V magnitude of11.4 as of December 2014).
"...We would like to continue to monitor itsbehavior from the optical to the infrared (BVRIJHK and/or the equivalent Sloanfilters) as it appears to be changing. At least one set of observations perweek between now and the end of May would be ideal..."
BVRcIc and visual observations are requested every fewnights from now through the end of May. 2MASS J06593158-0405277 is approachingconjunction and in Monoceros is low in the West by the end of astronomicaltwilight. It will become increasingly difficult to observe, but please keepgoing as long as possible. The high airmass will not be a problem for therequired accuracy of the data - 10% photometry is fine. For the most accuratecorrelation with the spectroscopic data, it is important that the photometry betransformed.
Coordinates: R.A. 06 59 31.59 Dec. -04 05 27.8 (2000.0)
Charts with a comparison star sequence for 2MASSJ06593158-0405277 may be created using the AAVSO Variable Star Plotter (VSP,http::/www.aavso.org/vsp).
Please submit observations to the AAVSO InternationalDatabase using the name 2MASS J06593158-0405277.
This AAVSO Alert Notice was compiled by Elizabeth O.Waagen.
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This soundsgreat -- 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 todayit's already at airmass of 2. It's certainly still observable, but data quality may notbe 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; unlessB-V is more than 2 then B will also be doable. Wedo 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 possiblewith the diode photometers they use. We will askfor 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.
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發表於 2015-4-16 12:17:18