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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"

19048 results found.

  1. GRB010222, radio observations
  2. GRB010222, optical observations
  3. GRB010220, Radio and Optical Observations
  4. GRB 010220, simultaneous optical observations
  5. GRB010220: BeppoSAX WFC and GRBM preliminary data
  6. GRB010214, optical observations
  7. BeppoSAX GRB010220: refined position
  8. GRB010214: BeppoSAX WFC and GRBM preliminary data
  9. GRB 010214: X-Ray afterglow
  10. GRB 010214 optical observation
  11. J-Band Observation of GRB 010214.
  12. GRB010213, Near-IR observations
  13. Possible InfraRed Transient of GRB 010214.
  14. GRB010213 (HETE) TAROT observations
  15. GRB010213 detected by HETE
  16. IPN Status Report
  17. HETE Status
  18. GRB010126 Optical Observations
  19. IPN TRIANGULATION OF GRB010126
  20. Optical Observations of GRB 001018 at Keck
  21. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  22. Optical observations of GRB 001018 with JCAM
  23. IPN TRIANGULATION OF GRB010115
  24. IPN TRIANGULATION OF GRB010109
  25. IPN TRIANGULATION OF GRB010109
  26. IPN triangulation of GRB010104
  27. IPN triangulation of GRB010103
  28. IPN triangulation of GRB001219
  29. GRB 001212 Optical Observation
  30. GRB 001212 Optical Observation
  31. GRB 001212 possible OA
  32. IPN triangulation of GRB001212
  33. Confirmation of IPN position for GRB001204
  34. IPN triangulation of GRB001204 (short/hard)
  35. GRB001120, optical observations
  36. WSRT 4.8 GHz observations of GRB001109
  37. IPN triangulation of GRB001120
  38. GRB 001109: deep JHK upper limits
  39. GRB 001109 X-ray afterglow with BeppoSAX
  40. CORRECTION to XMM-Newton observation of GRB001025
  41. GRB001109, Radio observations
  42. BeppoSAX ALERT: GRB001109
  43. GRB001105 BVRI field photometry correction
  44. GRB001105, BVRI field photometry
  45. IPN TRIANGULATION OF GRB001105
  46. GRB 001025B, Optical obervations
  47. GRB 991208: HST Imaging of the Host Galaxy
  48. GRB 001025B, I-band observations
  49. XMM-Newton observation of GRB001025
  50. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  51. GRB001007: Optical observations
  52. ASM Localization of GRB 001025
  53. GRB001007, Radio observations
  54. IPN TRIANGULATION OF GRB001019
  55. IPN TRIANGULATION OF GRB001018
  56. IPN TRIANGULATION OF GRB 001017
  57. V,R,I band observations of GRB000926
  58. HETE positions added to GCN
  59. GRB 001007, BVR-band observations
  60. GRB000926 - Amateur Optical Observations
  61. CONCAM null result on GRB001005
  62. IPN triangulation of GRB001007
  63. GRB000926 - Optical observations
  64. GRB000926 - Optical observations
  65. GRB 000926, Optical Observations
  66. GRB000926 K'-band Observation
  67. J and K band observations of GRB 000926
  68. GRB000911 Optical Observations
  69. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  70. CONCAM crude optical limits before and after GRB000926
  71. GRB 000926: Optical candidate
  72. Optical candidate for GRB000926
  73. IPN triangulation of GRB000926
  74. GRB 000911, BVRI field photometry
  75. GRB000911, Radio and Optical observations
  76. GRB000911: Optical observations
  77. IPN triangulation of GRB000910
  78. GRB000830, BVRI field photometry
  79. GRB000801, VLT-Antu R-band observations
  80. GRB000301C, UBVI optical observations
  81. GRB000801, Radio Observations
  82. GRB 991208 Host Galaxy Imaging
  83. IPN localization of GRB000730B
  84. IPN localization of GRB000730B
  85. GRB 990510: Possible detection of a host galaxy
  86. GRB 990510 Host Galaxy Discovery
  87. GRB 990712: Late time HST/STIS Observations
  88. GRB 991216, HST/STIS observations
  89. GRB000630, optical observations
  90. GRB000630, Revised BVRI Field Photometry
  91. GRB000630, Optical Observations
  92. GRB000630, optical observations
  93. GRB000630, optical observations
  94. GRB000630, BVRI Field Photometry
  95. GRB000630, optical observations
  96. GRB000630: Optical observations
  97. possible optical counterpart of GRB 000630
  98. GRB 000620, optical observations
  99. GRB000418, HST/STIS Observations
  100. GRB990123: Late-time HST/STIS observations of the host

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