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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"

38363 results found.

  1. GRB010213, Near-IR observations
  2. Possible InfraRed Transient of GRB 010214.
  3. GRB010214 Optical Observation
  4. GRB010214: BeppoSAX/NFI Observations
  5. GRB010213 (HETE) TAROT observations
  6. GRB 010214, optical observations
  7. GRB010213 detected by HETE
  8. GRB010214 refined WFC position
  9. BeppoSAX ALERT: GRB010214
  10. IPN Status Report
  11. GRB010126 opt. obs.
  12. IPN/RXTE TRIANGULATION OF GRB010126
  13. GRB010126: CONCAM crude optical limits during GRB
  14. GRB010126, TNG R-band observations
  15. GRB010126 Optical Observations
  16. GRB010126 optical observations
  17. GRB010126: Optical observations
  18. IPN TRIANGULATION OF GRB010126
  19. IPN/RXTE TRIANGULATION OF GRB010126
  20. GRB 010119, optical observations
  21. GRB010119: Optical observations
  22. Optical Observations of GRB 001018 at Keck
  23. GRB010119, Radio observations
  24. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  25. Optical observations of GRB 001018 with JCAM
  26. IPN TRIANGULATION OF GRB010115
  27. IPN TRIANGULATION OF GRB010109
  28. IPN TRIANGULATION OF GRB010109
  29. GRB010103, optical observations
  30. IPN triangulation of GRB010104
  31. IPN triangulation of GRB010103
  32. GRB 001204: Ks observations
  33. H band observation of GRB 001212
  34. IPN triangulation of GRB001219
  35. GRB 001212 Optical Observation
  36. GRB 001212 Optical Observation
  37. GRB 001212 optical observation
  38. GRB 001212 possible OA in 2MASS
  39. GRB 001212 possible OA
  40. IPN triangulation of GRB001212
  41. GRB001204: Optical observations
  42. Confirmation of IPN position for GRB001204
  43. GRB001204, Radio observations
  44. IPN triangulation of GRB001204 (short/hard)
  45. GRB 001105, further optical observations
  46. GRB001120: Gunn-i observations
  47. GRB001120: Optical observations
  48. GRB001109, optical observations
  49. GRB001120, optical observations
  50. WSRT 4.8 GHz observations of GRB001109
  51. IPN triangulation of GRB001120
  52. Optical/NIR observations of GRB001109
  53. GRB 001109: deep JHK upper limits
  54. CORRECTION to XMM-Newton observation of GRB001025
  55. GRB001109: Optical observations
  56. GRB001109: BeppoSAX/NFI Observations
  57. GRB001109, R-band optical observations
  58. GRB001109, Radio observations
  59. GRB001109: BeppoSAX refined WFC position
  60. BeppoSAX ALERT: GRB001109
  61. GRB001105, BVRI field photometry
  62. GRB 001105, R-band observation
  63. IPN TRIANGULATION OF GRB001105
  64. GRB 001025B, Optical obervations
  65. GRB 991208: HST Imaging of the Host Galaxy
  66. GRB000926: R-image of the host galaxy
  67. GRB 001025B, I-band observations
  68. GRB001025B, Radio observations
  69. GRB 001025 Optical Observations
  70. GRB 001025A, optical observation
  71. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  72. IPN triangulation of GRB001025
  73. GRB001007: Optical observations
  74. ASM Localization of GRB 001025
  75. GRB001007, Radio observations
  76. IPN TRIANGULATION OF GRB001020
  77. GRB001019, Optical Observations
  78. GRB 001018, Possible Radio Afterglow
  79. GRB001018, Gamma Ray Observations
  80. IPN TRIANGULATION OF GRB001019
  81. IPN TRIANGULATION OF GRB001018
  82. IPN TRIANGULATION OF GRB 001017
  83. GRB 000926: Improved Absorber Redshift
  84. V,R,I band observations of GRB000926
  85. The Likely Optical/Infrared Afterglow of GRB 001011
  86. HETE positions added to GCN
  87. GRB001011 BeppoSAX/WFC refined position
  88. BeppoSAX ALERT: GRB001011
  89. GRB 001007, BVR-band observations
  90. GRB000926 - Amateur Optical Observations
  91. GRB001007: Optical observations
  92. CONCAM null result on GRB001005
  93. IPN triangulation of GRB001007
  94. GRB 000926 : the host galaxy
  95. HETE-2 Launches Successfully
  96. IPN triangulation of GRB001005
  97. HETE-2 48 hour Launch Delay
  98. GRB 000926 Chandra Observation
  99. IPN triangulation of GRB 001004
  100. GRB000926: X-ray afterglow by BeppoSAX: revised fluxes (fwd)

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