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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"

45428 results found.

  1. GRB000126 Optical Observations
  2. GRB 991208, radio observations
  3. BATSE+IPN location of GRB000131
  4. IPN localization of GRB000131
  5. GRB 000126, optical observations
  6. GRB000126, optical observations
  7. BATSE location of GRB000126
  8. IPN localization of GRB000126
  9. GRB 000115 Optical observations
  10. BATSE Observations of GRB000115
  11. Correction to GCN 520 (IPN annulus for GRB000115)
  12. Second RXTE Observation of GRB 000115
  13. GRB991216, UBVRIJHK field photometry
  14. GRB991216 late optical observation
  15. Single IPN error box for GRB991229
  16. GCN resumes full operations
  17. GRB 991216 VLBA Observations
  18. BEPPOSAX GRBM Localization of GRB991226
  19. IPN error boxes for GRB991229
  20. GRB 991216: J band spectrophotometry
  21. GRB 991216: Detection of the Host and/or Absorber Galaxy
  22. IPN localization of GRB991226
  23. Single IPN error box for GRB991221
  24. IPN error boxes for GRB991221
  25. GRB 991216 RXTE ASM Observations
  26. IPN error box for GRB991216
  27. GRB 991216: Updated BATSE parameters
  28. Lowell/Perkins observation of GRB 991216
  29. GRB 991217 (SAX J2303.2+0015) Optical observations
  30. GRB991217/SAX J2303.2+0015, optical observations
  31. Chandra observation of the X-ray afterglow of GRB991216
  32. GRB 991216, optical observations
  33. GRB 991216 Optical Observations
  34. GRB 991216 Optical spectroscopy/imaging
  35. VLT spectra of GRB991216
  36. GRB991216 Optical and IR observations
  37. K observations of GRB991216
  38. SAX J2303.2+0015 Optical observations
  39. IR observations of GRB991216
  40. GRB991216 radio observations
  41. GRB991216 radio observations
  42. GRB991216 Spectroscopy
  43. Lowell/Perkins observation of GRB 991216
  44. GRB991216, optical observations
  45. GRB991216 Optical and infrared observations of Beethoven Burst
  46. Refined IPN localization of GRB991216
  47. GRB 991216 Radio Observations
  48. GRB 991217
  49. GRB 991208 Keck Spectroscopy
  50. GRB 991208 Infrared Detection
  51. GRB991216
  52. GRB 991216--Summary of RXTE Observations
  53. GRB 991216 Optical Observations
  54. GRB 991216, optical observations
  55. GRB 991208 SAO-RAS Spectroscopy
  56. SAX J2303.2+0015: an x-ray/GRB?
  57. GRB 991216, Optical Transient
  58. GRB 991216, Optical Afterglow
  59. GRB991216 ('Beethoven Burst') B, R, and K Observations
  60. GRB 991216: Comparison with DPOSS images
  61. GRB991216, infrared observations
  62. GRB991216 Optical Observations
  63. GRB 991208 optical observations
  64. Lowell/Perkins observation of GRB 991216
  65. GRB 991216 Optical Observation
  66. GRB 991208 Keck Spectroscopy
  67. GRB 991216: Extremely bright BATSE burst
  68. R-band Observations of GRB991208 at TNG
  69. GRB991208, optical observations
  70. GRB 991208 Keck Spectroscopy
  71. GRB991208 - millimeter detection
  72. GRB 991208, Optical Observation
  73. GRB991208 15-GHz observations
  74. GRB991208, optical observations
  75. GRB 991208 - OVRO detection
  76. GRB 991208 Optical Decay
  77. GRB 991208 optical observations
  78. GRB 991208 optical observations
  79. GRB 991208: Radio Observations
  80. IPN localization of GRB991208
  81. Optical Observations of GRB991105
  82. GRB991106: BeppoSAX/BATSE results
  83. GRB 991106, optical observations
  84. GRB991106, near-infrared observations
  85. BeppoSAX NFI Observation of GRB991106
  86. GRB 991106, radio observations
  87. GRB991106: the first BeppoSAX short GRB detection?
  88. GRB 991105: BATSE Observations
  89. IPN localization of GRB991105
  90. GRB 991106 Optical Observations
  91. GRB 991105, optical observations
  92. GRB991106, optical observation at SAO-RAS
  93. GRB 991106, LOTIS Optical Observations
  94. GRB 991106, optical observations
  95. BeppoSAX refined position for GRB991106
  96. BeppoSAX GRB Alert: GRB991106
  97. Revised BeppoSAX WFC position of GRB991105
  98. GRB991105: SAX-GRBM/-WFC detection
  99. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  100. GRB ALERT: GRB991105

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