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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"

41684 results found.

  1. GRB000418, near-infrared observations
  2. BeppoSAX GRB000424
  3. Correction to IPN error box for GRB000419
  4. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  5. GRB000416 BRJK observations
  6. 1SAXJ1715.0-7134 refined position
  7. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  8. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  9. Budget cuts in BeppoSAX operations: impact on GRB observations
  10. GRB 000408, optical observations
  11. Refined IPN error box for GRB000408
  12. GRB 991208, UBVRI field photometry
  13. GRB000301c results
  14. GRB000408: Optical CCD Observations from MIRO
  15. GRB000408, lotis optical observations
  16. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  17. GRB000326 Optical Observations
  18. GRB000301C - Addendum to GCN 623
  19. GRB000301C - R magnitude lower limit
  20. GRB000326, Further VLA observations
  21. GRB 000323, optical observations
  22. GRB 000326: Optical Observations
  23. GRB000326, Radio observations
  24. GRB 000307 optical observations
  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. GRB 000301c: K' observations
  40. GRB000301C, optical R-band observations
  41. GRB000301c - R photometry and nearby faint source confirmation
  42. GRB 000301C, Optical Observation
  43. GRB 000301C Optical Observations
  44. GRB 000301C: K' Observations
  45. GRB000301C OT candidate optical observations
  46. GRB000301C - Host galaxy not detected in R (?)
  47. Optical observations of GRB000301c
  48. GRB000301C, Radio observations
  49. GRB000301C, Radio observations
  50. GRB000301C optical observations
  51. GRB000301C, near-infrared observations (JHK' imaging)
  52. GRB 000301c near-IR observations
  53. GRB 000301C, Optical Color
  54. GRB 000301C, UBVRI field photometry
  55. GRB 000301C, Optical Observation
  56. GRB000301C, optical observations
  57. GRB000301C 250 GHz detection
  58. GRB 000301C R-band observation
  59. GRB 000301C, Optical Observation
  60. GRB000301C, near-infrared observations (JHK' photometry)
  61. GRB 000301C: OT confirmed
  62. GRB000301c optical observations
  63. GRB 000301A, Radio Observations
  64. GRB000301C, optical observations
  65. GRB000301c, near-infrared observations
  66. GRB000301C
  67. GRB 000301C : Optical Candidate
  68. Radio observations of the error box of GRB000301A
  69. GRB000301C: RXTE/ASM and IPN localizations
  70. HST Observations of GRB 990712
  71. GRB 000214 near-IR observations
  72. GRB 000115 Optical observations
  73. GRB 000214, Radio Observations
  74. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  75. GRB000210, Radio Observations
  76. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  77. GRB 000115, BVRI field photometry
  78. GRB000214: BeppoSAX GRBM and WFC Detection
  79. IPN annulus for GRB000214
  80. BATSE GRB trigger criterion changed
  81. Optical observations of GRB000210
  82. GRB000210 X-ray afterglow
  83. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  84. GRB 000210: BATSE Observations
  85. Correction to Chandra Position of GRB000210 afterglow
  86. Optical observations of the Chandra X-ray source for GRB000210
  87. GRB000210, Radio Observations
  88. Optical candidate for GRB000210
  89. Chandra Observations of GRB000210 X-ray Afterglow
  90. IPN triangulation of GRB000210
  91. GRB000201, Radio Observations
  92. GRB000210: BeppoSAX GRBM and WFC Detection
  93. Optical observations of GRB000131
  94. GRB000201 Optical Observations
  95. GRB 000201: TAROT optical observations
  96. GRB 000131 Optical Observations
  97. GRB000126 Optical Observations
  98. BATSE GRB trigger criteria changed
  99. GRB 991208, radio observations
  100. BATSE+IPN location of GRB000131

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