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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
  1. SGR 1806-20 burst activity
  2. GRB000812, TNG R-band observations
  3. GRB000801 & GRB000730, Gamma Ray Observations
  4. GRB000730, Gamma Ray Observations
  5. GRB000812, Radio observations
  6. IPN localization of GRB000812
  7. IPN localization of GRB000811
  8. GRB000801, Gamma Ray Observations
  9. GRB000801, VLT-Antu R-band observations
  10. GRB000301C, UBVI optical observations
  11. GRB000801, Radio Observations
  12. GRB 991208 Host Galaxy Imaging
  13. Updated IPN coordinates for GRB000801
  14. IPN localization of GRB000801
  15. IPN localization of GRB000801
  16. IPN localization of GRB000730B
  17. IPN localization of GRB000730B
  18. IPN localization of GRB000730
  19. GRB 990510: Possible detection of a host galaxy
  20. GRB 990510 Host Galaxy Discovery
  21. GRB 000727, optical observations
  22. IPN localization of GRB000727
  23. GRB 990705, HST/STIS observations of the host galaxy
  24. GRB 990712: Late time HST/STIS Observations
  25. GRB 991216, HST/STIS observations
  26. GRB000620, Radio Observations
  27. GRB981226, HST/STIS observations of the host galaxy
  28. GRB000630, optical observations
  29. GRB 000630: Detection of the Optical Afterglow
  30. GRB000630, Revised BVRI Field Photometry
  31. GRB000630, Optical Observations
  32. GRB000630, optical observations
  33. GRB000630, optical observations
  34. GRB000630, BVRI Field Photometry
  35. GRB000630, optical observations
  36. GRB000630, optical observations
  37. GRB000630: Optical observations
  38. GRB000630, Radio Observations
  39. possible optical counterpart of GRB 000630
  40. IPN triangulation of GRB000630
  41. GRB 000623, optical observations
  42. GRB 000620, optical observations
  43. GRB000418, HST/STIS Observations
  44. GRB990123: Late-time HST/STIS observations of the host
  45. GRB 990506, HST/STIS Observations of the Host Galaxy
  46. GRB000623
  47. GRB 000620: J-band observations
  48. GRB000620, optical observations
  49. GRB000615: H-band observations
  50. GRB990308, HST/STIS observations of the host galaxy
  51. GRB000620 - Optical observations
  52. GRB000620 Optical observations
  53. IPN annulus for GRB000620
  54. GRB000620: BeppoSAX WFC and GRBM detection
  55. GRB000615, Radio observations
  56. GRB000607, optical observations
  57. GRB 000615: NIR further observations
  58. GRB000620: refined BeppoSAX/WFC coordinates
  59. BeppoSAX ALERT: GRB000620
  60. GRB000620: BeppoSAX Alert
  61. GRB990123, HST/STIS observations of the host galaxy
  62. GRB000616 optical observations
  63. GRB 000615, near-infrared observations
  64. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  65. GRB000616 [IPN Position]
  66. GRB000615B [IPN Position]
  67. GRB000615, further R-band photometry
  68. GRB 000615: NIR observations
  69. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  70. GRB000615, R-band photometry
  71. GRB000615: BeppoSAX refined coordinates
  72. GRB980425, HST/STIS observations of the host galaxy
  73. GRB000615: BeppoSAX GRB Alert
  74. The Hosts of GRB 980703 and GRB 971214
  75. GRB 000301C: Further Late-Time HST/STIS observations
  76. GRB000528: follow-up X-ray measurements and update of IPN annulus
  77. Optical Follow-up of GRB000529 Error Box
  78. GRB980519, HST/STIS observations of the host galaxy
  79. GRB000607, Radio Observations
  80. BeppoSAX X-ray transient/possible GRB000608
  81. GRB000604 optical non-detection
  82. GRB000604 - Optical observations
  83. GRB000607, A SHORT, HARD BURST
  84. GRB000604, optical observations
  85. GRB000528, optical observations at ESO
  86. GRB 000604 optical observations
  87. GRB 000418: Detection of the Host Galaxy
  88. GRB000604, optical observations, comparison with DPOSS
  89. GRB000604 [IPN Position]
  90. GRB000528, Radio Observations
  91. X-ray Afterglow of GRB 000529
  92. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  93. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  94. GRB000529: Optical Observations
  95. IPN localization and time history of GRB000528
  96. New IPN localization of GRB000529
  97. GRB000519: Optical observations
  98. IPN localization of GRB000529
  99. GRB 000528 - WFC measurements
  100. GRB000529: BeppoSAX WFC position

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