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T Tauri and NGC 1555

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#1 brownrb1


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Posted 29 December 2019 - 12:48 PM

T Tauri A.png T Tauri_Burnham's Nebula_12_19_2019_40sx10 - Copy A _GIMP.jpg


     I was observing last week (12/19/2019) and got a image of one of my favorite stars, T Tauri, and the reflection nebula-NGC 1555 or Hind's Nebula-which is illuminated by T Tauri. Also there appears to be a faint nebulosity on the edge of T Tauri, which may be HH255, or Burnham's Nebula. Also attached is a spectral profile of T Tauri that I got 12/27/2016 with a 10" f/4.7 Newtonian, SA-100 grating, Atik Infinity, and RSpec. The visual image was obtained with a !0" f/10 Meade SCT, Meade f/6.3 focal reducer, and an Atik Infinity monochrome camera with 40s exposure, stacked 10 times and used GIMP to brighten the nebulosity.

     T Tauri is low-mass, 0.53 solar mass, pre-main sequence object that is in transition between being a star shrouded in dust (an IR source), produced by a strong stellar wind, and a main sequence star. There are strong emission lines-the Balmer lines can be seen in my spectral profile-and also Ca ll and Fe emission lines and lithium absorption lines are present-but not resolved in my spectrum. I have a Alpy 600 that I hope to use soon to get a spectrum of T Tauri with better resolution. The energy source for T-Tauri stars is, initially, gravitational energy released as the star contracts and as central pressures increase "lithium burning" by the Proton-Proton (P-P) chain begins. I'm not sure where T Tauri is in that sequence of gravitational to thermonuclear energy production. Again, T Tauri stars are some of my favorites-as are those on the other extreme of the main sequence,Wolfe-Rayet stars. Also I plan on examining Be stars with my Alpy. With a high resolution spectrograph, such as a Shelyak Lhires lll, one can resolve emission spectra on the stars and get meaningful data from observation of Be stars as the intensity of these emission lines change with time. O so much to be done and so little time, but onward and upward. 



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#2 mwr


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Posted 15 February 2020 - 06:38 AM

T Tauri and NGC 1555 are really  difficult objects to capture with my setup (https://www.cloudyni...9437-equipment/). 

NGC 1555 remained almost invisble even after a 420 sec exposure. T Tauri was bright enough to get a noisy SA-200 spectrum with a detectable H alpha emission:




Differential photometry was possible (10.5 mag) and is in good agreement with AAVSO data:




A comparison with ProAm spectra from the BAA database (taken by J.Foster and K. Gurney) shows nicely how the [O I] and [S II] lines are broadened beyond detectability (also due to the low S/N ratio):




For Rainer K√∂hler (a professional astrophysicist at the University of Vienna) T Tauri is his favorite object and he wrote a beautiful summary on it : https://homepage.uni...Object-TTau.pdf

Edited by mwr, 15 February 2020 - 05:03 PM.

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