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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"

41696 results found.

  1. GRB 000429, UBVRI field photometry
  2. GRB 000418, UBVRI field photometry
  3. GRB000418, Radio detection
  4. GRB000418, K'-band photometry
  5. GRB 000418, Optical Observation
  6. GRB 000418, optical observation
  7. GRB000424 Optical Observations
  8. GRB 000418, Optical Observation
  9. GRB000424, optical observations
  10. GRB000424, optical observations
  11. GRB 000424, Optical Observations
  12. GRB 000418, Optical Observation
  13. GRB000418, near-infrared observations
  14. BeppoSAX GRB000424
  15. Correction to IPN error box for GRB000419
  16. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  17. GRB000416 BRJK observations
  18. 1SAXJ1715.0-7134 refined position
  19. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  20. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  21. Budget cuts in BeppoSAX operations: impact on GRB observations
  22. GRB 000408, optical observations
  23. Refined IPN error box for GRB000408
  24. GRB 991208, UBVRI field photometry
  25. GRB000301c results
  26. GRB000408: Optical CCD Observations from MIRO
  27. GRB000408, lotis optical observations
  28. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  29. GRB000326 Optical Observations
  30. GRB000301C - Addendum to GCN 623
  31. GRB000301C - R magnitude lower limit
  32. GRB000326, Further VLA observations
  33. GRB 000323, optical observations
  34. GRB 000326: Optical Observations
  35. GRB000326, Radio observations
  36. GRB 000307 optical observations
  37. Single error box for GRB000315
  38. GRB000315 [IPN Positions]
  39. GRB000313, Radio observations
  40. GRB 000313 - optical transient in the BATSE error box
  41. GRB000301C - B and R photometry
  42. GRB000301C - R photometry
  43. GRB 000307, Optical Observations
  44. GRB 000307, BVRI Field Photometry
  45. GRB 000301C: Optical Spectrum and Redshift
  46. GRB 000301C: Optical Spectrum and Redshift
  47. GRB 000301C: A Precise Redshift Determination
  48. GRB 000301C, Optical Observation
  49. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  50. GRB 000301C: HST/STIS CCD Imaging of the field
  51. GRB 000301c: K' observations
  52. GRB000301C, optical R-band observations
  53. GRB000301c - R photometry and nearby faint source confirmation
  54. GRB 000301C, Optical Observation
  55. GRB 000301C Optical Observations
  56. GRB 000301C: K' Observations
  57. GRB000301C OT candidate optical observations
  58. GRB000301C - Host galaxy not detected in R (?)
  59. Optical observations of GRB000301c
  60. GRB000301C, Radio observations
  61. GRB000301C, Radio observations
  62. GRB000301C optical observations
  63. GRB000301C, near-infrared observations (JHK' imaging)
  64. GRB 000301c near-IR observations
  65. GRB 000301C, Optical Color
  66. GRB 000301C, UBVRI field photometry
  67. GRB 000301C, Optical Observation
  68. GRB000301C, optical observations
  69. GRB000301C 250 GHz detection
  70. GRB 000301C R-band observation
  71. GRB 000301C, Optical Observation
  72. GRB000301C, near-infrared observations (JHK' photometry)
  73. GRB 000301C: OT confirmed
  74. GRB000301c optical observations
  75. GRB 000301A, Radio Observations
  76. GRB000301C, optical observations
  77. GRB000301c, near-infrared observations
  78. GRB000301C
  79. GRB 000301C : Optical Candidate
  80. Radio observations of the error box of GRB000301A
  81. GRB000301C: RXTE/ASM and IPN localizations
  82. HST Observations of GRB 990712
  83. GRB 000214 near-IR observations
  84. GRB 000115 Optical observations
  85. GRB 000214, Radio Observations
  86. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  87. GRB000210, Radio Observations
  88. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  89. GRB 000115, BVRI field photometry
  90. GRB000214: BeppoSAX GRBM and WFC Detection
  91. IPN annulus for GRB000214
  92. BATSE GRB trigger criterion changed
  93. Optical observations of GRB000210
  94. GRB000210 X-ray afterglow
  95. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  96. GRB 000210: BATSE Observations
  97. Correction to Chandra Position of GRB000210 afterglow
  98. Optical observations of the Chandra X-ray source for GRB000210
  99. GRB000210, Radio Observations
  100. Optical candidate for GRB000210

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