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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"

18833 results found.

  1. IPN Status Report
  2. HETE Status
  3. GRB010126 Optical Observations
  4. IPN TRIANGULATION OF GRB010126
  5. Optical Observations of GRB 001018 at Keck
  6. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  7. Optical observations of GRB 001018 with JCAM
  8. IPN TRIANGULATION OF GRB010115
  9. IPN TRIANGULATION OF GRB010109
  10. IPN TRIANGULATION OF GRB010109
  11. IPN triangulation of GRB010104
  12. IPN triangulation of GRB010103
  13. IPN triangulation of GRB001219
  14. GRB 001212 Optical Observation
  15. GRB 001212 Optical Observation
  16. GRB 001212 possible OA
  17. IPN triangulation of GRB001212
  18. Confirmation of IPN position for GRB001204
  19. IPN triangulation of GRB001204 (short/hard)
  20. GRB001120, optical observations
  21. WSRT 4.8 GHz observations of GRB001109
  22. IPN triangulation of GRB001120
  23. GRB 001109: deep JHK upper limits
  24. GRB 001109 X-ray afterglow with BeppoSAX
  25. CORRECTION to XMM-Newton observation of GRB001025
  26. GRB001109, Radio observations
  27. BeppoSAX ALERT: GRB001109
  28. GRB001105 BVRI field photometry correction
  29. GRB001105, BVRI field photometry
  30. IPN TRIANGULATION OF GRB001105
  31. GRB 001025B, Optical obervations
  32. GRB 991208: HST Imaging of the Host Galaxy
  33. GRB 001025B, I-band observations
  34. XMM-Newton observation of GRB001025
  35. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  36. GRB001007: Optical observations
  37. ASM Localization of GRB 001025
  38. GRB001007, Radio observations
  39. IPN TRIANGULATION OF GRB001019
  40. IPN TRIANGULATION OF GRB001018
  41. IPN TRIANGULATION OF GRB 001017
  42. V,R,I band observations of GRB000926
  43. HETE positions added to GCN
  44. GRB 001007, BVR-band observations
  45. GRB000926 - Amateur Optical Observations
  46. CONCAM null result on GRB001005
  47. IPN triangulation of GRB001007
  48. GRB000926 - Optical observations
  49. GRB000926 - Optical observations
  50. GRB 000926, Optical Observations
  51. GRB000926 K'-band Observation
  52. J and K band observations of GRB 000926
  53. GRB000911 Optical Observations
  54. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  55. CONCAM crude optical limits before and after GRB000926
  56. GRB 000926: Optical candidate
  57. Optical candidate for GRB000926
  58. IPN triangulation of GRB000926
  59. GRB 000911, BVRI field photometry
  60. GRB000911, Radio and Optical observations
  61. GRB000911: Optical observations
  62. IPN triangulation of GRB000910
  63. GRB000830, BVRI field photometry
  64. GRB000801, VLT-Antu R-band observations
  65. GRB000301C, UBVI optical observations
  66. GRB000801, Radio Observations
  67. GRB 991208 Host Galaxy Imaging
  68. IPN localization of GRB000730B
  69. IPN localization of GRB000730B
  70. GRB 990510: Possible detection of a host galaxy
  71. GRB 990510 Host Galaxy Discovery
  72. GRB 990712: Late time HST/STIS Observations
  73. GRB 991216, HST/STIS observations
  74. GRB000630, optical observations
  75. GRB000630, Revised BVRI Field Photometry
  76. GRB000630, Optical Observations
  77. GRB000630, optical observations
  78. GRB000630, optical observations
  79. GRB000630, BVRI Field Photometry
  80. GRB000630, optical observations
  81. GRB000630: Optical observations
  82. possible optical counterpart of GRB 000630
  83. GRB 000620, optical observations
  84. GRB000418, HST/STIS Observations
  85. GRB990123: Late-time HST/STIS observations of the host
  86. GRB000620, optical observations
  87. GRB000620 - Optical observations
  88. GRB000620 Optical observations
  89. GRB000620: BeppoSAX WFC and GRBM detection
  90. GRB000615, Radio observations
  91. GRB000607, optical observations
  92. GRB 000615: NIR further observations
  93. GRB000616 optical observations
  94. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  95. GRB000615, further R-band photometry
  96. GRB 000615: NIR observations
  97. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  98. GRB000615, R-band photometry
  99. GRB 000301C: Further Late-Time HST/STIS observations
  100. GRB000528: follow-up X-ray measurements and update of IPN annulus

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