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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"

23445 results found.

  1. IPN TRIANGULATION OF GRB001018
  2. IPN TRIANGULATION OF GRB 001017
  3. V,R,I band observations of GRB000926
  4. HETE positions added to GCN
  5. GRB000926 - Amateur Optical Observations
  6. GRB001007: Optical observations
  7. CONCAM null result on GRB001005
  8. IPN triangulation of GRB001007
  9. IPN triangulation of GRB001005
  10. GRB 000926 Chandra Observation
  11. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  12. GRB000926 - Optical observations
  13. GRB000926 - Optical observations
  14. GRB 000926, Optical Observations
  15. GRB000926 K'-band Observation
  16. J and K band observations of GRB 000926
  17. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  18. CONCAM crude optical limits before and after GRB000926
  19. GRB 000926: Optical candidate
  20. Optical candidate for GRB000926
  21. IPN triangulation of GRB000926
  22. GRB 000911, BVRI field photometry
  23. IPN triangulation of GRB000925
  24. GRB000911, Radio and Optical observations
  25. GRB000911, Radio observations
  26. GRB000911: Optical observations
  27. IPN triangulation of GRB000911
  28. IPN triangulation of GRB000910
  29. GRB 000830: Optical observations
  30. GRB000830: Optical observations
  31. GRB000830, TNG B-band observations
  32. GRB000830, BVRI field photometry
  33. GRB000830: Optical observations
  34. GRB000830: Optical observations
  35. IPN triangulation of GRB000830
  36. IPN localization of GRB000820
  37. GRB000812, TNG R-band observations
  38. IPN localization of GRB000812
  39. IPN localization of GRB000811
  40. GRB000801, VLT-Antu R-band observations
  41. GRB 991208 Host Galaxy Imaging
  42. IPN localization of GRB000801
  43. IPN localization of GRB000730B
  44. IPN localization of GRB000730B
  45. IPN localization of GRB000730
  46. GRB 990510: Possible detection of a host galaxy
  47. GRB 990510 Host Galaxy Discovery
  48. IPN localization of GRB000727
  49. GRB 990712: Late time HST/STIS Observations
  50. GRB 991216, HST/STIS observations
  51. GRB000630, optical observations
  52. GRB000630, Revised BVRI Field Photometry
  53. GRB000630, Optical Observations
  54. GRB000630, optical observations
  55. GRB000630, optical observations
  56. GRB000630, BVRI Field Photometry
  57. GRB000630, optical observations
  58. GRB000630: Optical observations
  59. possible optical counterpart of GRB 000630
  60. IPN triangulation of GRB000630
  61. GRB 000620, optical observations
  62. GRB000418, HST/STIS Observations
  63. GRB990123: Late-time HST/STIS observations of the host
  64. GRB000623
  65. GRB000620, optical observations
  66. GRB000615: H-band observations
  67. GRB000620 - Optical observations
  68. GRB000620 Optical observations
  69. IPN annulus for GRB000620
  70. GRB000620: BeppoSAX WFC and GRBM detection
  71. GRB000607, optical observations
  72. GRB 000615: NIR further observations
  73. GRB990123, HST/STIS observations of the host galaxy
  74. GRB000616 optical observations
  75. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  76. GRB000616 [IPN Position]
  77. GRB000615B [IPN Position]
  78. GRB000615, further R-band photometry
  79. GRB 000615: NIR observations
  80. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  81. GRB000615, R-band photometry
  82. GRB 000301C: Further Late-Time HST/STIS observations
  83. GRB000528: follow-up X-ray measurements and update of IPN annulus
  84. Optical Follow-up of GRB000529 Error Box
  85. GRB000604 optical non-detection
  86. GRB000604 - Optical observations
  87. GRB000607, A SHORT, HARD BURST
  88. GRB000604, optical observations
  89. GRB000528, optical observations at ESO
  90. GRB 000604 optical observations
  91. GRB 000418: Detection of the Host Galaxy
  92. GRB000604, optical observations, comparison with DPOSS
  93. GRB000604 [IPN Position]
  94. GRB000528, Radio Observations
  95. X-ray Afterglow of GRB 000529
  96. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  97. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  98. GRB000529: Optical Observations
  99. IPN localization and time history of GRB000528
  100. IPN localization of GRB000529

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