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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"

20355 results found.

  1. GRB010222, possible increase of optical decay slope
  2. GRB 010222 Kyoto optical observation
  3. GRB 010222 BV optical observations
  4. GRB010222 R-BAND OBSERVATION
  5. GRB010214 follow-up from Hanle
  6. GRB 010222: Near-IR Observations
  7. GRB 010222: Optical Observations
  8. GRB010222, radio observations
  9. GRB010222, optical observations
  10. GRB010220, Radio and Optical Observations
  11. GRB 010220, simultaneous optical observations
  12. GRB010220: BeppoSAX WFC and GRBM preliminary data
  13. GRB010214, optical observations
  14. BeppoSAX GRB010220: refined position
  15. GRB010214: BeppoSAX WFC and GRBM preliminary data
  16. GRB 010214: X-Ray afterglow
  17. GRB 010214 optical observation
  18. J-Band Observation of GRB 010214.
  19. GRB010213, Near-IR observations
  20. Possible InfraRed Transient of GRB 010214.
  21. GRB010213 (HETE) TAROT observations
  22. GRB010213 detected by HETE
  23. IPN Status Report
  24. HETE Status
  25. GRB010126 Optical Observations
  26. IPN TRIANGULATION OF GRB010126
  27. Optical Observations of GRB 001018 at Keck
  28. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  29. Optical observations of GRB 001018 with JCAM
  30. IPN TRIANGULATION OF GRB010115
  31. IPN TRIANGULATION OF GRB010109
  32. IPN TRIANGULATION OF GRB010109
  33. IPN triangulation of GRB010104
  34. IPN triangulation of GRB010103
  35. IPN triangulation of GRB001219
  36. GRB 001212 Optical Observation
  37. GRB 001212 Optical Observation
  38. GRB 001212 possible OA
  39. IPN triangulation of GRB001212
  40. Confirmation of IPN position for GRB001204
  41. IPN triangulation of GRB001204 (short/hard)
  42. GRB001120, optical observations
  43. WSRT 4.8 GHz observations of GRB001109
  44. IPN triangulation of GRB001120
  45. GRB 001109: deep JHK upper limits
  46. GRB 001109 X-ray afterglow with BeppoSAX
  47. CORRECTION to XMM-Newton observation of GRB001025
  48. GRB001109, Radio observations
  49. BeppoSAX ALERT: GRB001109
  50. GRB001105 BVRI field photometry correction
  51. GRB001105, BVRI field photometry
  52. IPN TRIANGULATION OF GRB001105
  53. GRB 001025B, Optical obervations
  54. GRB 991208: HST Imaging of the Host Galaxy
  55. GRB 001025B, I-band observations
  56. XMM-Newton observation of GRB001025
  57. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  58. GRB001007: Optical observations
  59. ASM Localization of GRB 001025
  60. GRB001007, Radio observations
  61. IPN TRIANGULATION OF GRB001019
  62. IPN TRIANGULATION OF GRB001018
  63. IPN TRIANGULATION OF GRB 001017
  64. V,R,I band observations of GRB000926
  65. HETE positions added to GCN
  66. GRB 001007, BVR-band observations
  67. GRB000926 - Amateur Optical Observations
  68. CONCAM null result on GRB001005
  69. IPN triangulation of GRB001007
  70. GRB000926 - Optical observations
  71. GRB000926 - Optical observations
  72. GRB 000926, Optical Observations
  73. GRB000926 K'-band Observation
  74. J and K band observations of GRB 000926
  75. GRB000911 Optical Observations
  76. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  77. CONCAM crude optical limits before and after GRB000926
  78. GRB 000926: Optical candidate
  79. Optical candidate for GRB000926
  80. IPN triangulation of GRB000926
  81. GRB 000911, BVRI field photometry
  82. GRB000911, Radio and Optical observations
  83. GRB000911: Optical observations
  84. IPN triangulation of GRB000910
  85. GRB000830, BVRI field photometry
  86. GRB000801, VLT-Antu R-band observations
  87. GRB000301C, UBVI optical observations
  88. GRB000801, Radio Observations
  89. GRB 991208 Host Galaxy Imaging
  90. IPN localization of GRB000730B
  91. IPN localization of GRB000730B
  92. GRB 990510: Possible detection of a host galaxy
  93. GRB 990510 Host Galaxy Discovery
  94. GRB 990712: Late time HST/STIS Observations
  95. GRB 991216, HST/STIS observations
  96. GRB000630, optical observations
  97. GRB000630, Revised BVRI Field Photometry
  98. GRB000630, Optical Observations
  99. GRB000630, optical observations
  100. GRB000630, optical observations

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