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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"

44348 results found.

  1. GRB000418, Radio detection
  2. GRB000418, K'-band photometry
  3. GRB 000418, Optical Observation
  4. GRB 000418, optical observation
  5. GRB000424 Optical Observations
  6. GRB 000418, Optical Observation
  7. GRB000424, optical observations
  8. GRB000424, optical observations
  9. GRB 000424, Optical Observations
  10. GRB 000418, Optical Observation
  11. GRB000418, near-infrared observations
  12. BeppoSAX GRB000424
  13. Correction to IPN error box for GRB000419
  14. IPN error box for GRB000418
  15. GRB000419 [IPN Position]
  16. GRB000416 Optical Observations
  17. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  18. GRB000416 BRJK observations
  19. 1SAXJ1715.0-7134 refined position
  20. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  21. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  22. Budget cuts in BeppoSAX operations: impact on GRB observations
  23. GRB 000408, optical observations
  24. Refined IPN error box for GRB000408
  25. GRB 991208, UBVRI field photometry
  26. GRB000301c results
  27. GRB000408: Optical CCD Observations from MIRO
  28. GRB000408, lotis optical observations
  29. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  30. GRB000408 [IPN Position]
  31. GRB000326 Optical Observations
  32. GRB000301C - Addendum to GCN 623
  33. GRB000301C - R magnitude lower limit
  34. GRB000326, Further VLA observations
  35. GRB 000323, optical observations
  36. GRB 000326: Optical Observations
  37. GRB000326, Radio observations
  38. GRB000326 [IPN Position]
  39. GRB 000307 optical observations
  40. GRB000323 [IPN Position]
  41. Single error box for GRB000315
  42. GRB000315 [IPN Positions]
  43. GRB000313, Radio observations
  44. GRB 000313 - optical transient in the BATSE error box
  45. GRB000301C - B and R photometry
  46. GRB000301C - R photometry
  47. GRB 000307, Optical Observations
  48. GRB 000307, BVRI Field Photometry
  49. GRB 000301C: Optical Spectrum and Redshift
  50. GRB 000301C: Optical Spectrum and Redshift
  51. GRB 000301C: A Precise Redshift Determination
  52. GRB 000301C, Optical Observation
  53. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  54. GRB 000301C: HST/STIS CCD Imaging of the field
  55. IPN error box for GRB000307
  56. GRB 000301c: K' observations
  57. GRB000301C, optical R-band observations
  58. GRB000301c - R photometry and nearby faint source confirmation
  59. GRB 000301C, Optical Observation
  60. GRB 000301c: K' observations
  61. GRB 000301C Optical Observations
  62. GRB 000301C: K' Observations
  63. GRB000301C OT candidate optical observations
  64. GRB000301C - Host galaxy not detected in R (?)
  65. Optical observations of GRB000301c
  66. GRB000301C, Radio observations
  67. GRB000301C, Radio observations
  68. GRB000301C optical observations
  69. GRB000301C, near-infrared observations (JHK' imaging)
  70. GRB 000301c near-IR observations
  71. GRB 000301C, Optical Color
  72. GRB000301C, Optical Spectroscopy
  73. GRB 000301C, UBVRI field photometry
  74. GRB 000301C, Optical Observation
  75. GRB000301C, optical observations
  76. GRB000301C 250 GHz detection
  77. GRB 000301C R-band observation
  78. GRB 000301C, Optical Observation
  79. GRB000301C, near-infrared observations (JHK' photometry)
  80. GRB 000301C: OT confirmed
  81. GRB000301c optical observations
  82. GRB 000301A, Radio Observations
  83. GRB000301C, optical observations
  84. GRB000301c, near-infrared observations
  85. GRB000301C
  86. GRB 000301C : Optical Candidate
  87. Radio observations of the error box of GRB000301A
  88. GRB000301C: RXTE/ASM and IPN localizations
  89. GRB000226 [IPN Position]
  90. HST Observations of GRB 990712
  91. GRB 000214 near-IR observations
  92. GRB 000115 Optical observations
  93. GRB 000214, Radio Observations
  94. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  95. GRB000210, Radio Observations
  96. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  97. GRB 000115, BVRI field photometry
  98. GRB000214: BeppoSAX GRBM and WFC Detection
  99. IPN annulus for GRB000214
  100. Optical observations of GRB000210

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