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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"

19861 results found.

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

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