I've been experimenting with itelescope.net and tried to observe Sgr A*.

I was wondering if there are any suggestions how I can best observe the surrounding stars.


I expect that all the itelescope.net instruments work at visible wavelengths. Therefore you have no chance at all to image the stars around Sgr A*, since it is behind about 25-30 magnitudes of optical extinction, caused by dust between us and the Galactic centre.

The published images you have seen were taken by large telescopes working with adaptive optics in the near-infrared (wavelengths longer than 1.5 $\mu$m). At these longer wavelengths the extinction caused by dust is only 2-3 magnitudes.

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    $\begingroup$ Actually it appears that some of the telescopes do have extended red sensitivity: support.itelescope.net/support/solutions/articles/…: T17 is a Science Platform. Normally used for Science Missions, Deep Photometry, Narrowband and 'Extended Red' light IR imaging. It is equipped with a FLI ProLine E2V CCD47-10-1-109 CCD. that has 'extended red sensitivity' when compared to standard CCD’s. Giving it an almost 'Near Infrared' mission profile. $\endgroup$ – Nickpick Aug 30 '19 at 8:45
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    $\begingroup$ @Nickpick It is still an optical CCD and as such has no sensitivity at wavelengths beyond the 1.1 $\mu$m that is required for a photon to excite an electron across the Si band gap. With this CCD/instrument the best you could do is observe through the broad band I filter, but the extinction to the GC is still about 15 magnitudes at this wavelength. $\endgroup$ – ProfRob Aug 30 '19 at 10:02
  • $\begingroup$ Are there any publicly available telescope that offer that sensitivity? If not, is there any raw data available that I could download? $\endgroup$ – Nickpick Aug 30 '19 at 13:17
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    $\begingroup$ @Nickpick That sounds like a good, new question. $\endgroup$ – ProfRob Aug 30 '19 at 13:21
  • $\begingroup$ here we go: astronomy.stackexchange.com/questions/33204/… $\endgroup$ – Nickpick Aug 30 '19 at 13:22

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