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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. GRB 000307, Optical Observations
  2. GRB 000307, BVRI Field Photometry
  3. GRB 000301C: Optical Spectrum and Redshift
  4. GRB 000301C: Optical Spectrum and Redshift
  5. GRB 000301C: A Precise Redshift Determination
  6. GRB 000301C, Optical Observation
  7. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  8. GRB 000301C: HST/STIS CCD Imaging of the field
  9. IPN error box for GRB000307
  10. GRB 000301c: K' observations
  11. GRB000301C, optical R-band observations
  12. GRB000301c - R photometry and nearby faint source confirmation
  13. GRB 000301C, Optical Observation
  14. GRB 000301c: K' observations
  15. GRB 000301C Optical Observations
  16. GRB 000301C: K' Observations
  17. GRB000301C OT candidate optical observations
  18. GRB000301C - Host galaxy not detected in R (?)
  19. Optical observations of GRB000301c
  20. GRB000301C, Radio observations
  21. GRB000301C, Radio observations
  22. GRB000301C optical observations
  23. GRB000301C, near-infrared observations (JHK' imaging)
  24. GRB 000301c near-IR observations
  25. GRB 000301C, Optical Color
  26. GRB000301C, Optical Spectroscopy
  27. GRB 000301C, UBVRI field photometry
  28. GRB 000301C, Optical Observation
  29. GRB000301C, optical observations
  30. GRB000301C 250 GHz detection
  31. GRB 000301C R-band observation
  32. GRB 000301C, Optical Observation
  33. GRB000301C, near-infrared observations (JHK' photometry)
  34. GRB 000301C: OT confirmed
  35. GRB000301c optical observations
  36. GRB 000301A, Radio Observations
  37. GRB000301C, optical observations
  38. GRB000301c, near-infrared observations
  39. GRB000301C
  40. GRB 000301C : Optical Candidate
  41. Radio observations of the error box of GRB000301A
  42. GRB000301C: RXTE/ASM and IPN localizations
  43. GRB000301A [IPN Position]
  44. GRB000226 [IPN Position]
  45. HST Observations of GRB 990712
  46. GRB 000214 near-IR observations
  47. GRB 000115 Optical observations
  48. GRB 000214, Radio Observations
  49. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  50. GRB000210, Radio Observations
  51. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  52. GRB 000115, BVRI field photometry
  53. GRB000214: BeppoSAX GRBM and WFC Detection
  54. IPN annulus for GRB000214
  55. BATSE GRB trigger criterion changed
  56. Optical observations of GRB000210
  57. GRB000210 X-ray afterglow
  58. GRB000214: X-ray afterglow candidate
  59. GRB000214 refined BeppoSAX-WFC position
  60. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  61. GRB 000210: BATSE Observations
  62. Correction to Chandra Position of GRB000210 afterglow
  63. Optical observations of the Chandra X-ray source for GRB000210
  64. GRB000210, Radio Observations
  65. Optical candidate for GRB000210
  66. Chandra Observations of GRB000210 X-ray Afterglow
  67. IPN triangulation of GRB000210
  68. GRB000210: possible afterglow detection with BeppoSAX NFI
  69. GRB000201, Radio Observations
  70. GRB000210: BeppoSAX GRBM and WFC Detection
  71. SAX_WFC_GRB_NOTICE
  72. SAX_WFC_GRB_NOTICE
  73. Optical observations of GRB000131
  74. GRB000201 Optical Observations
  75. GRB 000201: TAROT optical observations
  76. GRB 000131 Optical Observations
  77. GRB000126 Optical Observations
  78. BATSE GRB trigger criteria changed
  79. GRB 991208, radio observations
  80. BATSE+IPN location of GRB000131
  81. IPN localization of GRB000131
  82. GRB 000126, optical observations
  83. GRB000126, optical observations
  84. BATSE location of GRB000126
  85. IPN localization of GRB000126
  86. GRB 000115 Optical observations
  87. BATSE Observations of GRB000115
  88. Correction to GCN 520 (IPN annulus for GRB000115)
  89. IPN annulus for GRB000115
  90. Second RXTE Observation of GRB 000115
  91. GRB991216, UBVRIJHK field photometry
  92. GRB991216 late optical observation
  93. Single IPN error box for GRB991229
  94. GCN resumes full operations
  95. GRB 991216 VLBA Observations
  96. BEPPOSAX GRBM Localization of GRB991226
  97. IPN error boxes for GRB991229
  98. GRB 991216: J band spectrophotometry
  99. GRB 991216: Detection of the Host and/or Absorber Galaxy
  100. IPN localization of GRB991226

Advanced

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