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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. GRB981226, HST/STIS observations of the host galaxy
  2. GRB000630, optical observations
  3. GRB 000630: Detection of the Optical Afterglow
  4. GRB000630, Revised BVRI Field Photometry
  5. GRB000630, Optical Observations
  6. GRB000630, optical observations
  7. GRB000630, optical observations
  8. GRB000630, BVRI Field Photometry
  9. GRB000630, optical observations
  10. GRB000630, optical observations
  11. GRB000630: Optical observations
  12. GRB000630, Radio Observations
  13. possible optical counterpart of GRB 000630
  14. IPN triangulation of GRB000630
  15. GRB 000623, optical observations
  16. GRB 000620, optical observations
  17. GRB000418, HST/STIS Observations
  18. GRB990123: Late-time HST/STIS observations of the host
  19. GRB 990506, HST/STIS Observations of the Host Galaxy
  20. GRB000623
  21. GRB 000620: J-band observations
  22. GRB000620, optical observations
  23. GRB000615: H-band observations
  24. GRB990308, HST/STIS observations of the host galaxy
  25. GRB000620 - Optical observations
  26. GRB000620 Optical observations
  27. IPN annulus for GRB000620
  28. GRB000620: BeppoSAX WFC and GRBM detection
  29. GRB000615, Radio observations
  30. GRB000607, optical observations
  31. GRB 000615: NIR further observations
  32. GRB000620: refined BeppoSAX/WFC coordinates
  33. BeppoSAX ALERT: GRB000620
  34. GRB000620: BeppoSAX Alert
  35. GRB990123, HST/STIS observations of the host galaxy
  36. GRB000616 optical observations
  37. GRB 000615, near-infrared observations
  38. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  39. GRB000616 [IPN Position]
  40. GRB000615B [IPN Position]
  41. GRB000615, further R-band photometry
  42. GRB 000615: NIR observations
  43. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  44. GRB000615, R-band photometry
  45. GRB000615: BeppoSAX refined coordinates
  46. GRB980425, HST/STIS observations of the host galaxy
  47. GRB000615: BeppoSAX GRB Alert
  48. The Hosts of GRB 980703 and GRB 971214
  49. GRB 000301C: Further Late-Time HST/STIS observations
  50. GRB000528: follow-up X-ray measurements and update of IPN annulus
  51. Optical Follow-up of GRB000529 Error Box
  52. GRB980519, HST/STIS observations of the host galaxy
  53. GRB000607, Radio Observations
  54. BeppoSAX X-ray transient/possible GRB000608
  55. GRB000604 optical non-detection
  56. GRB000604 - Optical observations
  57. GRB000607, A SHORT, HARD BURST
  58. GRB000604, optical observations
  59. GRB000528, optical observations at ESO
  60. GRB 000604 optical observations
  61. GRB 000418: Detection of the Host Galaxy
  62. GRB000604, optical observations, comparison with DPOSS
  63. GRB000604 [IPN Position]
  64. GRB000528, Radio Observations
  65. X-ray Afterglow of GRB 000529
  66. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  67. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  68. GRB000529: Optical Observations
  69. IPN localization and time history of GRB000528
  70. New IPN localization of GRB000529
  71. GRB000519: Optical observations
  72. IPN localization of GRB000529
  73. GRB 000528 - WFC measurements
  74. GRB000529: BeppoSAX WFC position
  75. GRB000528: BeppoSAX GRBM observations
  76. GRB 000528 Optical Observations
  77. GRB000519, BVRI field photometry
  78. IPN triangulation of GRB000519
  79. IPN triangulation of GRB000516
  80. Re: GRB000508B : Optical observations
  81. GRB 000418, Optical observation
  82. GRB000508B, optical photometry
  83. GRB000508B, BVR field photometry
  84. Possible GRB-related phenomenon
  85. RXTE/ASM and IPN localization of GRB 000508B
  86. GRB000424, UBVRI field photometry
  87. GRB 000424 Optical Observations
  88. GRB000418, UBVRI field photometry update
  89. The redshift of GRB 000418
  90. GRB000424, optical observations
  91. GRB 000429, optical observation
  92. GRB 000429, UBVRI field photometry
  93. IPN localization of GRB000429
  94. GRB 000418, UBVRI field photometry
  95. GRB000418, Radio detection
  96. GRB000418, K'-band photometry
  97. GRB 000418, Optical Observation
  98. GRB 000418, optical observation
  99. GRB000424 Optical Observations
  100. GRB 000418, Optical Observation

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