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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"

42786 results found.

  1. GRB010214, Radio Observations
  2. GRB010214, optical observations
  3. GRB010213, optical observations
  4. GRB010213, Near-IR observations
  5. Possible InfraRed Transient of GRB 010214.
  6. GRB010214 Optical Observation
  7. GRB010213 (HETE) TAROT observations
  8. GRB 010214, optical observations
  9. GRB010213 detected by HETE
  10. BeppoSAX ALERT: GRB010214
  11. IPN Status Report
  12. HETE Status
  13. GRB010126 opt. obs.
  14. IPN/RXTE TRIANGULATION OF GRB010126
  15. GRB010126: CONCAM crude optical limits during GRB
  16. GRB010126, TNG R-band observations
  17. GRB010126 Optical Observations
  18. GRB010126 optical observations
  19. GRB010126: Optical observations
  20. IPN TRIANGULATION OF GRB010126
  21. IPN/RXTE TRIANGULATION OF GRB010126
  22. GRB 010119, optical observations
  23. GRB010119: Optical observations
  24. Optical Observations of GRB 001018 at Keck
  25. GRB010119, Radio observations
  26. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  27. Optical observations of GRB 001018 with JCAM
  28. IPN TRIANGULATION OF GRB010115
  29. IPN TRIANGULATION OF GRB010109
  30. IPN TRIANGULATION OF GRB010109
  31. GRB010103, optical observations
  32. IPN triangulation of GRB010104
  33. IPN triangulation of GRB010103
  34. GRB 001204: Ks observations
  35. H band observation of GRB 001212
  36. IPN triangulation of GRB001219
  37. GRB 001212 Optical Observation
  38. GRB 001212 Optical Observation
  39. GRB 001212 optical observation
  40. GRB 001212 possible OA in 2MASS
  41. GRB 001212 possible OA
  42. IPN triangulation of GRB001212
  43. GRB001204: Optical observations
  44. Confirmation of IPN position for GRB001204
  45. GRB001204, Radio observations
  46. IPN triangulation of GRB001204 (short/hard)
  47. GRB 001105, further optical observations
  48. GRB001120: Gunn-i observations
  49. GRB001120: Optical observations
  50. GRB001109, optical observations
  51. GRB001120, optical observations
  52. WSRT 4.8 GHz observations of GRB001109
  53. IPN triangulation of GRB001120
  54. Optical/NIR observations of GRB001109
  55. GRB 001109: deep JHK upper limits
  56. GRB 001109 X-ray afterglow with BeppoSAX
  57. CORRECTION to XMM-Newton observation of GRB001025
  58. GRB001109: Optical observations
  59. GRB001109: BeppoSAX/NFI Observations
  60. GRB001109, R-band optical observations
  61. GRB001109, Radio observations
  62. BeppoSAX ALERT: GRB001109
  63. GRB001105, BVRI field photometry
  64. GRB 001105, R-band observation
  65. IPN TRIANGULATION OF GRB001105
  66. GRB 001025B, Optical obervations
  67. GRB 991208: HST Imaging of the Host Galaxy
  68. GRB 001025B, I-band observations
  69. XMM-Newton observation of GRB001025
  70. GRB001025B, Radio observations
  71. GRB 001025 Optical Observations
  72. GRB 001025A, optical observation
  73. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  74. IPN triangulation of GRB001025
  75. GRB001007: Optical observations
  76. ASM Localization of GRB 001025
  77. GRB001007, Radio observations
  78. IPN TRIANGULATION OF GRB001020
  79. GRB001019, Optical Observations
  80. GRB 001018, Possible Radio Afterglow
  81. GRB001018, Gamma Ray Observations
  82. IPN TRIANGULATION OF GRB001019
  83. CORRECTION TO PEAK FLUX OF GRB001018
  84. IPN TRIANGULATION OF GRB001018
  85. IPN TRIANGULATION OF GRB 001017
  86. GRB 000926: Improved Absorber Redshift
  87. V,R,I band observations of GRB000926
  88. The Likely Optical/Infrared Afterglow of GRB 001011
  89. HETE positions added to GCN
  90. BeppoSAX ALERT: GRB001011
  91. GRB 001007, BVR-band observations
  92. GRB000926 - Amateur Optical Observations
  93. GRB001007: Optical observations
  94. CONCAM null result on GRB001005
  95. IPN triangulation of GRB001007
  96. GRB 000926 : the host galaxy
  97. HETE-2 Launches Successfully
  98. IPN triangulation of GRB001005
  99. HETE-2 48 hour Launch Delay
  100. GRB 000926 Chandra Observation

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