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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"

32498 results found.

  1. Correction to Chandra Position of GRB000210 afterglow
  2. Optical observations of the Chandra X-ray source for GRB000210
  3. GRB000210, Radio Observations
  4. Optical candidate for GRB000210
  5. Chandra Observations of GRB000210 X-ray Afterglow
  6. IPN triangulation of GRB000210
  7. GRB000201, Radio Observations
  8. Optical observations of GRB000131
  9. GRB000201 Optical Observations
  10. GRB 000131 Optical Observations
  11. GRB000126 Optical Observations
  12. GRB 991208, radio observations
  13. BATSE+IPN location of GRB000131
  14. GRB 000126, optical observations
  15. GRB000126, optical observations
  16. BATSE location of GRB000126
  17. GRB 000115 Optical observations
  18. BATSE Observations of GRB000115
  19. Correction to GCN 520 (IPN annulus for GRB000115)
  20. IPN annulus for GRB000115
  21. GRB991216, UBVRIJHK field photometry
  22. GRB991216 late optical observation
  23. Single IPN error box for GRB991229
  24. GCN resumes full operations
  25. GRB 991216 VLBA Observations
  26. BEPPOSAX GRBM Localization of GRB991226
  27. GRB 991216: J band spectrophotometry
  28. GRB 991216: Detection of the Host and/or Absorber Galaxy
  29. Single IPN error box for GRB991221
  30. GRB 991216 RXTE ASM Observations
  31. IPN error box for GRB991216
  32. Lowell/Perkins observation of GRB 991216
  33. GRB 991217 (SAX J2303.2+0015) Optical observations
  34. GRB991217/SAX J2303.2+0015, optical observations
  35. Chandra observation of the X-ray afterglow of GRB991216
  36. GRB 991216, optical observations
  37. GRB 991216 Optical Observations
  38. GRB 991216 Optical spectroscopy/imaging
  39. VLT spectra of GRB991216
  40. GRB991216 Optical and IR observations
  41. SAX J2303.2+0015 Optical observations
  42. IR observations of GRB991216
  43. GRB991216 radio observations
  44. GRB 991217 (SAX J2303.2+0015) Optical observations
  45. GRB991216 radio observations
  46. Lowell/Perkins observation of GRB 991216
  47. GRB991216, optical observations
  48. Refined IPN localization of GRB991216
  49. GRB 991216 Radio Observations
  50. GRB 991208 Keck Spectroscopy
  51. GRB 991208 Infrared Detection
  52. GRB991216
  53. GRB 991216--Summary of RXTE Observations
  54. GRB 991216 Optical Observations
  55. GRB 991216, optical observations
  56. GRB 991208 SAO-RAS Spectroscopy
  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. GRB 991208 optical observations
  62. Lowell/Perkins observation of GRB 991216
  63. GRB 991216 Optical Observation
  64. GRB 991208 Keck Spectroscopy
  65. R-band Observations of GRB991208 at TNG
  66. GRB991208, optical observations
  67. GRB 991208 Keck Spectroscopy
  68. GRB991208 - millimeter detection
  69. GRB 991208, Optical Observation
  70. GRB991208 15-GHz observations
  71. GRB991208, optical observations
  72. GRB 991208 - OVRO detection
  73. GRB 991208 Optical Decay
  74. GRB 991208 optical observations
  75. GRB 991208 optical observations
  76. GRB 991208: Radio Observations
  77. Optical Observations of GRB991105
  78. GRB991106: BeppoSAX/BATSE results
  79. GRB 991106, optical observations
  80. GRB991106, near-infrared observations
  81. BeppoSAX NFI Observation of GRB991106
  82. GRB 991106, radio observations
  83. GRB 991105: BATSE Observations
  84. IPN localization of GRB991105
  85. GRB 991106 Optical Observations
  86. GRB 991105, optical observations
  87. GRB991106, optical observation at SAO-RAS
  88. GRB 991106, LOTIS Optical Observations
  89. GRB 991106, optical observations
  90. Revised BeppoSAX WFC position of GRB991105
  91. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  92. GRB 991014, Optical Observations
  93. GRB 991014 - BeppoSAX NFI observations
  94. GRB 991014, Optical Observations
  95. GRB 991014, Optical Observations
  96. GRB 991014, optical observations
  97. Super-LOTIS optical observation of GRB991014
  98. IPN/NFI error box for GRB991014
  99. IPN localization of GRB991014 - CORRECTION
  100. IPN localization of GRB991014

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