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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"

20958 results found.

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

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