Astronomical Satellites: Is My Object Visible

Please select the satellite and give date & time along with coordinates in specified format to see whether the source was visible for respective satellite or not.

Awaiting input...

The coordinates should be separated by SPACE
Please enter coordinates in following format :
210.76d -12.251d ("-" sign indicates negative value for Dec)
14h45m36.0s -12d15m3.6s ("-" sign indicates negative value for Dec)
05h34m31.94s 22d00m52.20s
83.633d 22.015d


  • About Us:
  • This satvis tool was developed by Soumyadeep Bhattacharjee (IITB, IISc), Varun Bhalerao (IITB) and Atharva Pore (IUCAA) and is hosted by
    AstroSat Science Support Cell.

    If you use this in your work, please include the line "This work made use of the Satvis tool developed by IIT Bombay and hosted by AstroSat Science Support Cell."
  • Disclaimer :
  • The orbits used in this calculation were calculated using current satellite TLEs from Celestrack.
    The boundaries of SAA and the Earth-occulted regions may be off by a couple of degrees. User discretion is advised while using these results.
  • References: This work made use of the following tools and packages:
    1. Numpy : Harris, C.R. et al., 2020. Array programming with NumPy. Nature, 585, pp.357–362 Version: 1.18.1
    2. Matplotlib: Thomas A Caswell et al. (2020) matplotlib/matplotlib v3.1.3. Version: 3.1.3
    3. Astropy: The Astropy Collaboration; A&A 558 A33 (2013); DOI: 10.1051/0004-6361/201322068; Astropy Collaboration, “The Astropy Project: Building an Open-science Project and Status of the v2.0 Core Package”, The Astronomical Journal, vol. 156, no. 3, 2018. doi:10.3847/1538-3881/aabc4f Version: 4.0
    4. Healpy: Andrea Zonca et al. (2020) healpy/healpy: 1.14.0. Version: 1.14.0
    5. Skyfield: Rhodes, B., “Skyfield: High precision research-grade positions for planets and Earth satellites generator”, Astrophysics Source Code Library, 2019. ascl:1907.024. Version: 1.37
    6. ligo.skymap: Leo P. Singer et al 2016 ApJL 829 L15 Version: 0.5.0
    7. Pandas: Jeff Reback et al. (2020) pandas-dev/pandas: Pandas 1.1.5. Version: 1.1.5
  • Additional resources used :
    1. Fermi SAA polygon definition
    2. Satellite TLE obtained from Celestrack
    3. Astrosat SAA definition credit: CZTI Team, Astrosat
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