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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"

21793 results found.

  1. GRB010214 Optical Observation
  2. GRB010214: BeppoSAX/NFI Observations
  3. GRB010213 (HETE) TAROT observations
  4. GRB 010214, optical observations
  5. GRB010213 detected by HETE
  6. GRB010126, TNG R-band observations
  7. GRB010126 Optical Observations
  8. GRB010126 optical observations
  9. GRB010126: Optical observations
  10. GRB 010119, optical observations
  11. GRB010119: Optical observations
  12. Optical Observations of GRB 001018 at Keck
  13. GRB010119, Radio observations
  14. Optical observations of GRB 001018 with JCAM
  15. GRB010103, optical observations
  16. GRB 001204: Ks observations
  17. H band observation of GRB 001212
  18. GRB 001212 possible OA
  19. GRB001204: Optical observations
  20. GRB001204, Radio observations
  21. GRB 001105, further optical observations
  22. GRB001120: Gunn-i observations
  23. GRB001120: Optical observations
  24. GRB001109, optical observations
  25. GRB001120, optical observations
  26. WSRT 4.8 GHz observations of GRB001109
  27. Optical/NIR observations of GRB001109
  28. GRB 001109: deep JHK upper limits
  29. GRB001109: Optical observations
  30. GRB001109: BeppoSAX/NFI Observations
  31. GRB001109, R-band optical observations
  32. GRB001109, Radio observations
  33. GRB 991208: HST Imaging of the Host Galaxy
  34. GRB000926: R-image of the host galaxy
  35. GRB 001025B, I-band observations
  36. GRB001025B, Radio observations
  37. GRB 001025 Optical Observations
  38. GRB001007: Optical observations
  39. GRB001007, Radio observations
  40. GRB001019, Optical Observations
  41. GRB 001018, Possible Radio Afterglow
  42. GRB001018, Gamma Ray Observations
  43. V,R,I band observations of GRB000926
  44. The Likely Optical/Infrared Afterglow of GRB 001011
  45. GRB 001007, BVR-band observations
  46. GRB000926 - Amateur Optical Observations
  47. GRB001007: Optical observations
  48. GRB 000926 : the host galaxy
  49. HETE-2 Launches Successfully
  50. GRB 000926 Chandra Observation
  51. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  52. GRB000926 - Optical observations
  53. GRB000926 - Optical observations
  54. GRB000926 - Optical observations
  55. GRB000926 - Optical observations
  56. GRB 000926: optical observations
  57. GRB 000926, Optical Observations
  58. GRB000926 - Optical observations
  59. GRB000911: optical VLT observations
  60. GRB000926 K'-band Observation
  61. GRB000926 optical observations
  62. GRB000926 - Optical observations
  63. J and K band observations of GRB 000926
  64. GRB000911 Optical Observations
  65. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  66. GRB000926: Optical observations
  67. GRB 000926 HST/Chandra TOO Status
  68. GRB000926, radio observations
  69. GRB 000926: Optical candidate
  70. GRB000911: Sub-millimeter observations
  71. GRB000911, Radio and Optical observations
  72. GRB000911, Radio observations
  73. GRB000911: Optical observations
  74. GRB 000830: Optical observations
  75. GRB000830: Optical observations
  76. GRB000830, TNG B-band observations
  77. GRB000830: Optical observations
  78. GRB000210, Optical observations
  79. "Snapshot" afterglow IDs and GRB 000830
  80. GRB000830: Optical observations
  81. HST/STIS observations of the host galaxy of GRB 980329
  82. HST/STIS observations of the chaotic environment of GRB 980613
  83. SGR 1806-20 burst activity
  84. GRB000812, TNG R-band observations
  85. GRB000801 & GRB000730, Gamma Ray Observations
  86. GRB000730, Gamma Ray Observations
  87. GRB000812, Radio observations
  88. GRB000801, Gamma Ray Observations
  89. GRB000801, VLT-Antu R-band observations
  90. GRB000301C, UBVI optical observations
  91. GRB000801, Radio Observations
  92. GRB 991208 Host Galaxy Imaging
  93. GRB 990510: Possible detection of a host galaxy
  94. GRB 990510 Host Galaxy Discovery
  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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