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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. GRB000607, A SHORT, HARD BURST
  2. GRB000604, optical observations
  3. GRB000528, optical observations at ESO
  4. GRB 000604 optical observations
  5. GRB 000418: Detection of the Host Galaxy
  6. GRB000604, optical observations, comparison with DPOSS
  7. GRB000604 [IPN Position]
  8. GRB000528, Radio Observations
  9. X-ray Afterglow of GRB 000529
  10. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  11. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  12. GRB000529: Optical Observations
  13. IPN localization and time history of GRB000528
  14. New IPN localization of GRB000529
  15. GRB000519: Optical observations
  16. IPN localization of GRB000529
  17. GRB 000528 - WFC measurements
  18. GRB000529: BeppoSAX WFC position
  19. GRB000528: BeppoSAX GRBM observations
  20. GRB 000528 Optical Observations
  21. GRB000519, BVRI field photometry
  22. IPN triangulation of GRB000519
  23. IPN triangulation of GRB000516
  24. Re: GRB000508B : Optical observations
  25. GRB 000418, Optical observation
  26. GRB000508B, optical photometry
  27. GRB000508B, BVR field photometry
  28. Possible GRB-related phenomenon
  29. RXTE/ASM and IPN localization of GRB 000508B
  30. GRB000424, UBVRI field photometry
  31. GRB 000424 Optical Observations
  32. GRB000418, UBVRI field photometry update
  33. The redshift of GRB 000418
  34. GRB000424, optical observations
  35. GRB 000429, optical observation
  36. GRB 000429, UBVRI field photometry
  37. IPN localization of GRB000429
  38. GRB 000418, UBVRI field photometry
  39. GRB000418, Radio detection
  40. GRB000418, K'-band photometry
  41. GRB 000418, Optical Observation
  42. GRB 000418, optical observation
  43. GRB000424 Optical Observations
  44. GRB 000418, Optical Observation
  45. GRB000424, optical observations
  46. GRB000424, optical observations
  47. GRB 000424, Optical Observations
  48. GRB 000418, Optical Observation
  49. GRB000418, near-infrared observations
  50. BeppoSAX GRB000424
  51. Correction to IPN error box for GRB000419
  52. IPN error box for GRB000418
  53. GRB000419 [IPN Position]
  54. GRB000416 Optical Observations
  55. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  56. GRB000416 BRJK observations
  57. 1SAXJ1715.0-7134 refined position
  58. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  59. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  60. Budget cuts in BeppoSAX operations: impact on GRB observations
  61. GRB 000408, optical observations
  62. Refined IPN error box for GRB000408
  63. GRB 991208, UBVRI field photometry
  64. GRB000301c results
  65. GRB000408: Optical CCD Observations from MIRO
  66. GRB000408, lotis optical observations
  67. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  68. GRB000408 [IPN Position]
  69. GRB000326 Optical Observations
  70. GRB000301C - Addendum to GCN 623
  71. GRB000301C - R magnitude lower limit
  72. GRB000326, Further VLA observations
  73. GRB 000323, optical observations
  74. GRB 000326: Optical Observations
  75. GRB000326, Radio observations
  76. GRB000326 [IPN Position]
  77. GRB 000307 optical observations
  78. GRB000323 [IPN Position]
  79. Single error box for GRB000315
  80. GRB000315 [IPN Positions]
  81. GRB000313, Radio observations
  82. GRB 000313 - optical transient in the BATSE error box
  83. GRB000301C - B and R photometry
  84. GRB000301C - R photometry
  85. GRB 000307, Optical Observations
  86. GRB 000307, BVRI Field Photometry
  87. GRB 000301C: Optical Spectrum and Redshift
  88. GRB 000301C: Optical Spectrum and Redshift
  89. GRB 000301C: A Precise Redshift Determination
  90. GRB 000301C, Optical Observation
  91. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  92. GRB 000301C: HST/STIS CCD Imaging of the field
  93. IPN error box for GRB000307
  94. GRB 000301c: K' observations
  95. GRB000301C, optical R-band observations
  96. GRB000301c - R photometry and nearby faint source confirmation
  97. GRB 000301C, Optical Observation
  98. GRB 000301c: K' observations
  99. GRB 000301C Optical Observations
  100. GRB 000301C: K' Observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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