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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"
  1. GRB000301C, near-infrared observations (JHK' imaging)
  2. GRB 000301c near-IR observations
  3. GRB 000301C, Optical Color
  4. GRB000301C, Optical Spectroscopy
  5. GRB 000301C, UBVRI field photometry
  6. GRB 000301C, Optical Observation
  7. GRB000301C, optical observations
  8. GRB000301C 250 GHz detection
  9. GRB 000301C R-band observation
  10. GRB 000301C, Optical Observation
  11. GRB000301C, near-infrared observations (JHK' photometry)
  12. GRB 000301C: OT confirmed
  13. GRB000301c optical observations
  14. GRB 000301A, Radio Observations
  15. GRB000301C, optical observations
  16. GRB000301c, near-infrared observations
  17. GRB000301C
  18. GRB 000301C : Optical Candidate
  19. Radio observations of the error box of GRB000301A
  20. GRB000301C: RXTE/ASM and IPN localizations
  21. GRB000301A [IPN Position]
  22. GRB000226 [IPN Position]
  23. HST Observations of GRB 990712
  24. GRB 000214 near-IR observations
  25. GRB 000115 Optical observations
  26. GRB 000214, Radio Observations
  27. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  28. GRB000210, Radio Observations
  29. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  30. GRB 000115, BVRI field photometry
  31. GRB000214: BeppoSAX GRBM and WFC Detection
  32. IPN annulus for GRB000214
  33. BATSE GRB trigger criterion changed
  34. Optical observations of GRB000210
  35. GRB000210 X-ray afterglow
  36. GRB000214: X-ray afterglow candidate
  37. GRB000214 refined BeppoSAX-WFC position
  38. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  39. GRB 000210: BATSE Observations
  40. Correction to Chandra Position of GRB000210 afterglow
  41. Optical observations of the Chandra X-ray source for GRB000210
  42. GRB000210, Radio Observations
  43. Optical candidate for GRB000210
  44. Chandra Observations of GRB000210 X-ray Afterglow
  45. IPN triangulation of GRB000210
  46. GRB000210: possible afterglow detection with BeppoSAX NFI
  47. GRB000201, Radio Observations
  48. GRB000210: BeppoSAX GRBM and WFC Detection
  49. SAX_WFC_GRB_NOTICE
  50. SAX_WFC_GRB_NOTICE
  51. Optical observations of GRB000131
  52. GRB000201 Optical Observations
  53. GRB 000201: TAROT optical observations
  54. GRB 000131 Optical Observations
  55. GRB000126 Optical Observations
  56. BATSE GRB trigger criteria changed
  57. GRB 991208, radio observations
  58. BATSE+IPN location of GRB000131
  59. IPN localization of GRB000131
  60. GRB 000126, optical observations
  61. GRB000126, optical observations
  62. BATSE location of GRB000126
  63. IPN localization of GRB000126
  64. GRB 000115 Optical observations
  65. BATSE Observations of GRB000115
  66. Correction to GCN 520 (IPN annulus for GRB000115)
  67. IPN annulus for GRB000115
  68. Second RXTE Observation of GRB 000115
  69. GRB991216, UBVRIJHK field photometry
  70. GRB991216 late optical observation
  71. Single IPN error box for GRB991229
  72. GCN resumes full operations
  73. GRB 991216 VLBA Observations
  74. BEPPOSAX GRBM Localization of GRB991226
  75. IPN error boxes for GRB991229
  76. GRB 991216: J band spectrophotometry
  77. GRB 991216: Detection of the Host and/or Absorber Galaxy
  78. IPN localization of GRB991226
  79. Single IPN error box for GRB991221
  80. IPN error boxes for GRB991221
  81. GRB 991216 RXTE ASM Observations
  82. IPN error box for GRB991216
  83. GRB 991216: Updated BATSE parameters
  84. Lowell/Perkins observation of GRB 991216
  85. GRB 991217 (SAX J2303.2+0015) Optical observations
  86. GRB991217/SAX J2303.2+0015, optical observations
  87. Chandra observation of the X-ray afterglow of GRB991216
  88. GRB 991216, optical observations
  89. GRB 991216 Optical Observations
  90. GRB 991216 Optical spectroscopy/imaging
  91. VLT spectra of GRB991216
  92. GRB991216 Optical and IR observations
  93. K observations of GRB991216
  94. SAX J2303.2+0015 Optical observations
  95. IR observations of GRB991216
  96. GRB991216 radio observations
  97. GRB 991217 (SAX J2303.2+0015) Optical observations
  98. GRB991216 radio observations
  99. GRB991216 Spectroscopy
  100. Lowell/Perkins observation of GRB 991216

Advanced

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