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

Advanced

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