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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"

22050 results found.

  1. GRB001007: Optical observations
  2. ASM Localization of GRB 001025
  3. GRB001007, Radio observations
  4. IPN TRIANGULATION OF GRB001020
  5. IPN TRIANGULATION OF GRB001019
  6. IPN TRIANGULATION OF GRB001018
  7. IPN TRIANGULATION OF GRB 001017
  8. V,R,I band observations of GRB000926
  9. HETE positions added to GCN
  10. GRB000926 - Amateur Optical Observations
  11. GRB001007: Optical observations
  12. CONCAM null result on GRB001005
  13. IPN triangulation of GRB001007
  14. IPN triangulation of GRB001005
  15. GRB 000926 Chandra Observation
  16. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  17. GRB000926 - Optical observations
  18. GRB000926 - Optical observations
  19. GRB 000926, Optical Observations
  20. GRB000926 K'-band Observation
  21. J and K band observations of GRB 000926
  22. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  23. CONCAM crude optical limits before and after GRB000926
  24. GRB 000926: Optical candidate
  25. Optical candidate for GRB000926
  26. IPN triangulation of GRB000926
  27. GRB 000911, BVRI field photometry
  28. IPN triangulation of GRB000925
  29. GRB000911, Radio and Optical observations
  30. GRB000911, Radio observations
  31. GRB000911: Optical observations
  32. IPN triangulation of GRB000911
  33. IPN triangulation of GRB000910
  34. GRB 000830: Optical observations
  35. GRB000830: Optical observations
  36. GRB000830, TNG B-band observations
  37. GRB000830, BVRI field photometry
  38. GRB000830: Optical observations
  39. GRB000830: Optical observations
  40. IPN triangulation of GRB000830
  41. IPN localization of GRB000820
  42. GRB000812, TNG R-band observations
  43. IPN localization of GRB000812
  44. IPN localization of GRB000811
  45. GRB000801, VLT-Antu R-band observations
  46. GRB 991208 Host Galaxy Imaging
  47. IPN localization of GRB000801
  48. IPN localization of GRB000730B
  49. IPN localization of GRB000730B
  50. IPN localization of GRB000730
  51. GRB 990510: Possible detection of a host galaxy
  52. GRB 990510 Host Galaxy Discovery
  53. IPN localization of GRB000727
  54. GRB 990712: Late time HST/STIS Observations
  55. GRB 991216, HST/STIS observations
  56. GRB000630, optical observations
  57. GRB000630, Revised BVRI Field Photometry
  58. GRB000630, Optical Observations
  59. GRB000630, optical observations
  60. GRB000630, optical observations
  61. GRB000630, BVRI Field Photometry
  62. GRB000630, optical observations
  63. GRB000630: Optical observations
  64. possible optical counterpart of GRB 000630
  65. IPN triangulation of GRB000630
  66. GRB 000620, optical observations
  67. GRB000418, HST/STIS Observations
  68. GRB990123: Late-time HST/STIS observations of the host
  69. GRB000623
  70. GRB000620, optical observations
  71. GRB000615: H-band observations
  72. GRB000620 - Optical observations
  73. GRB000620 Optical observations
  74. IPN annulus for GRB000620
  75. GRB000620: BeppoSAX WFC and GRBM detection
  76. GRB000607, optical observations
  77. GRB 000615: NIR further observations
  78. GRB990123, HST/STIS observations of the host galaxy
  79. GRB000616 optical observations
  80. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  81. GRB000616 [IPN Position]
  82. GRB000615B [IPN Position]
  83. GRB000615, further R-band photometry
  84. GRB 000615: NIR observations
  85. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  86. GRB000615, R-band photometry
  87. GRB 000301C: Further Late-Time HST/STIS observations
  88. GRB000528: follow-up X-ray measurements and update of IPN annulus
  89. Optical Follow-up of GRB000529 Error Box
  90. GRB000604 optical non-detection
  91. GRB000604 - Optical observations
  92. GRB000607, A SHORT, HARD BURST
  93. GRB000604, optical observations
  94. GRB000528, optical observations at ESO
  95. GRB 000604 optical observations
  96. GRB 000418: Detection of the Host Galaxy
  97. GRB000604, optical observations, comparison with DPOSS
  98. GRB000604 [IPN Position]
  99. GRB000528, Radio Observations
  100. X-ray Afterglow of GRB 000529

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