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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. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  2. GRB000416 BRJK observations
  3. 1SAXJ1715.0-7134 refined position
  4. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  5. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  6. Budget cuts in BeppoSAX operations: impact on GRB observations
  7. GRB 000408, optical observations
  8. Refined IPN error box for GRB000408
  9. GRB 991208, UBVRI field photometry
  10. GRB000301c results
  11. GRB000408: Optical CCD Observations from MIRO
  12. GRB000408, lotis optical observations
  13. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  14. GRB000408 [IPN Position]
  15. GRB000326 Optical Observations
  16. GRB000301C - Addendum to GCN 623
  17. GRB000301C - R magnitude lower limit
  18. GRB000326, Further VLA observations
  19. GRB 000323, optical observations
  20. GRB 000326: Optical Observations
  21. GRB000326, Radio observations
  22. GRB000326 [IPN Position]
  23. GRB 000307 optical observations
  24. GRB000323 [IPN Position]
  25. Single error box for GRB000315
  26. GRB000315 [IPN Positions]
  27. GRB000313, Radio observations
  28. GRB 000313 - optical transient in the BATSE error box
  29. GRB000301C - B and R photometry
  30. GRB000301C - R photometry
  31. GRB 000307, Optical Observations
  32. GRB 000307, BVRI Field Photometry
  33. GRB 000301C: Optical Spectrum and Redshift
  34. GRB 000301C: Optical Spectrum and Redshift
  35. GRB 000301C: A Precise Redshift Determination
  36. GRB 000301C, Optical Observation
  37. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  38. GRB 000301C: HST/STIS CCD Imaging of the field
  39. IPN error box for GRB000307
  40. GRB 000301c: K' observations
  41. GRB000301C, optical R-band observations
  42. GRB000301c - R photometry and nearby faint source confirmation
  43. GRB 000301C, Optical Observation
  44. GRB 000301c: K' observations
  45. GRB 000301C Optical Observations
  46. GRB 000301C: K' Observations
  47. GRB000301C OT candidate optical observations
  48. GRB000301C - Host galaxy not detected in R (?)
  49. Optical observations of GRB000301c
  50. GRB000301C, Radio observations
  51. GRB000301C, Radio observations
  52. GRB000301C optical observations
  53. GRB000301C, near-infrared observations (JHK' imaging)
  54. GRB 000301c near-IR observations
  55. GRB 000301C, Optical Color
  56. GRB000301C, Optical Spectroscopy
  57. GRB 000301C, UBVRI field photometry
  58. GRB 000301C, Optical Observation
  59. GRB000301C, optical observations
  60. GRB000301C 250 GHz detection
  61. GRB 000301C R-band observation
  62. GRB 000301C, Optical Observation
  63. GRB000301C, near-infrared observations (JHK' photometry)
  64. GRB 000301C: OT confirmed
  65. GRB000301c optical observations
  66. GRB 000301A, Radio Observations
  67. GRB000301C, optical observations
  68. GRB000301c, near-infrared observations
  69. GRB000301C
  70. GRB 000301C : Optical Candidate
  71. Radio observations of the error box of GRB000301A
  72. GRB000301C: RXTE/ASM and IPN localizations
  73. GRB000301A [IPN Position]
  74. GRB000226 [IPN Position]
  75. HST Observations of GRB 990712
  76. GRB 000214 near-IR observations
  77. GRB 000115 Optical observations
  78. GRB 000214, Radio Observations
  79. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  80. GRB000210, Radio Observations
  81. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  82. GRB 000115, BVRI field photometry
  83. GRB000214: BeppoSAX GRBM and WFC Detection
  84. IPN annulus for GRB000214
  85. BATSE GRB trigger criterion changed
  86. Optical observations of GRB000210
  87. GRB000210 X-ray afterglow
  88. GRB000214: X-ray afterglow candidate
  89. GRB000214 refined BeppoSAX-WFC position
  90. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  91. GRB 000210: BATSE Observations
  92. Correction to Chandra Position of GRB000210 afterglow
  93. Optical observations of the Chandra X-ray source for GRB000210
  94. GRB000210, Radio Observations
  95. Optical candidate for GRB000210
  96. Chandra Observations of GRB000210 X-ray Afterglow
  97. IPN triangulation of GRB000210
  98. GRB000210: possible afterglow detection with BeppoSAX NFI
  99. GRB000201, Radio Observations
  100. GRB000210: BeppoSAX GRBM and WFC Detection

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