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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').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

20957 results found.

  1. GRB010213, Radio Observations
  2. J-Band Observation of GRB 010214.
  3. GRB010214, Radio Observations
  4. GRB010214, optical observations
  5. GRB010213, optical observations
  6. GRB010213, Near-IR observations
  7. Possible InfraRed Transient of GRB 010214.
  8. GRB010214 Optical Observation
  9. GRB010214: BeppoSAX/NFI Observations
  10. GRB010213 (HETE) TAROT observations
  11. GRB 010214, optical observations
  12. GRB010213 detected by HETE
  13. HETE Status
  14. GRB010126, TNG R-band observations
  15. GRB010126 Optical Observations
  16. GRB010126 optical observations
  17. GRB010126: Optical observations
  18. GRB 010119, optical observations
  19. GRB010119: Optical observations
  20. Optical Observations of GRB 001018 at Keck
  21. GRB010119, Radio observations
  22. Optical observations of GRB 001018 with JCAM
  23. GRB010103, optical observations
  24. GRB 001204: Ks observations
  25. H band observation of GRB 001212
  26. GRB 001212 possible OA
  27. GRB001204: Optical observations
  28. GRB001204, Radio observations
  29. GRB 001105, further optical observations
  30. GRB001120: Gunn-i observations
  31. GRB001120: Optical observations
  32. GRB001109, optical observations
  33. GRB001120, optical observations
  34. WSRT 4.8 GHz observations of GRB001109
  35. Optical/NIR observations of GRB001109
  36. GRB 001109: deep JHK upper limits
  37. GRB001109: Optical observations
  38. GRB001109: BeppoSAX/NFI Observations
  39. GRB001109, R-band optical observations
  40. GRB001109, Radio observations
  41. GRB 001025B, I-band observations
  42. GRB001025B, Radio observations
  43. GRB 001025 Optical Observations
  44. GRB001007: Optical observations
  45. GRB001007, Radio observations
  46. GRB001019, Optical Observations
  47. GRB 001018, Possible Radio Afterglow
  48. GRB001018, Gamma Ray Observations
  49. V,R,I band observations of GRB000926
  50. The Likely Optical/Infrared Afterglow of GRB 001011
  51. GRB 001007, BVR-band observations
  52. GRB000926 - Amateur Optical Observations
  53. GRB001007: Optical observations
  54. GRB000926 - Optical observations
  55. GRB000926 - Optical observations
  56. GRB000926 - Optical observations
  57. GRB000926 - Optical observations
  58. GRB 000926: optical observations
  59. GRB 000926, Optical Observations
  60. GRB000926 - Optical observations
  61. GRB000911: optical VLT observations
  62. GRB000926 optical observations
  63. GRB000926 - Optical observations
  64. J and K band observations of GRB 000926
  65. GRB000911 Optical Observations
  66. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  67. GRB000926: Optical observations
  68. GRB 000926 HST/Chandra TOO Status
  69. GRB000926, radio observations
  70. GRB 000926: Optical candidate
  71. GRB000911: Sub-millimeter observations
  72. GRB000911, Radio and Optical observations
  73. GRB000911, Radio observations
  74. GRB000911: Optical observations
  75. GRB 000830: Optical observations
  76. GRB000830: Optical observations
  77. GRB000830, TNG B-band observations
  78. GRB000830: Optical observations
  79. GRB000210, Optical observations
  80. "Snapshot" afterglow IDs and GRB 000830
  81. GRB000830: Optical observations
  82. HST/STIS observations of the host galaxy of GRB 980329
  83. HST/STIS observations of the chaotic environment of GRB 980613
  84. SGR 1806-20 burst activity
  85. GRB000812, TNG R-band observations
  86. GRB000801 & GRB000730, Gamma Ray Observations
  87. GRB000730, Gamma Ray Observations
  88. GRB000812, Radio observations
  89. GRB000801, Gamma Ray Observations
  90. GRB000801, VLT-Antu R-band observations
  91. GRB000301C, UBVI optical observations
  92. GRB000801, Radio Observations
  93. GRB 990510: Possible detection of a host galaxy
  94. GRB 000727, optical observations
  95. GRB 990705, HST/STIS observations of the host galaxy
  96. GRB 990712: Late time HST/STIS Observations
  97. GRB 991216, HST/STIS observations
  98. GRB000620, Radio Observations
  99. GRB981226, HST/STIS observations of the host galaxy
  100. GRB000630, optical observations

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Download all Circulars as a .tar.gz archive (updated once a day):
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