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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"

37523 results found.

  1. GRB000418, K'-band photometry
  2. GRB 000418, Optical Observation
  3. GRB 000418, optical observation
  4. GRB000424 Optical Observations
  5. GRB 000418, Optical Observation
  6. GRB 000424, Optical Observations
  7. GRB 000418, Optical Observation
  8. GRB000418, near-infrared observations
  9. Correction to IPN error box for GRB000419
  10. IPN error box for GRB000418
  11. GRB000419 [IPN Position]
  12. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  13. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  14. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  15. Budget cuts in BeppoSAX operations: impact on GRB observations
  16. GRB 000408, optical observations
  17. Refined IPN error box for GRB000408
  18. GRB 991208, UBVRI field photometry
  19. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  20. GRB000408 [IPN Position]
  21. GRB000326 Optical Observations
  22. GRB000301C - Addendum to GCN 623
  23. GRB000301C - R magnitude lower limit
  24. GRB 000323, optical observations
  25. GRB 000326: Optical Observations
  26. GRB000326, Radio observations
  27. GRB000326 [IPN Position]
  28. GRB 000307 optical observations
  29. GRB000323 [IPN Position]
  30. GRB000315 [IPN Positions]
  31. GRB 000313 - optical transient in the BATSE error box
  32. GRB000301C - B and R photometry
  33. GRB000301C - R photometry
  34. GRB 000307, Optical Observations
  35. GRB 000307, BVRI Field Photometry
  36. GRB 000301C: Optical Spectrum and Redshift
  37. GRB 000301C: Optical Spectrum and Redshift
  38. GRB 000301C: A Precise Redshift Determination
  39. GRB 000301C, Optical Observation
  40. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  41. GRB 000301C: HST/STIS CCD Imaging of the field
  42. IPN error box for GRB000307
  43. GRB 000301c: K' observations
  44. GRB000301C, optical R-band observations
  45. GRB000301c - R photometry and nearby faint source confirmation
  46. GRB 000301C, Optical Observation
  47. GRB 000301c: K' observations
  48. GRB 000301C Optical Observations
  49. GRB 000301C: K' Observations
  50. GRB000301C - Host galaxy not detected in R (?)
  51. GRB000301C optical observations
  52. GRB 000301c near-IR observations
  53. GRB 000301C, Optical Color
  54. GRB000301C, Optical Spectroscopy
  55. GRB 000301C, UBVRI field photometry
  56. GRB 000301C, Optical Observation
  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. GRB000301C: RXTE/ASM and IPN localizations
  69. GRB000226 [IPN Position]
  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. GRB 000115, BVRI field photometry
  76. IPN annulus for GRB000214
  77. BATSE GRB trigger criterion changed
  78. GRB000210 X-ray afterglow
  79. GRB000214: X-ray afterglow candidate
  80. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  81. GRB 000210: BATSE Observations
  82. Optical observations of the Chandra X-ray source for GRB000210
  83. Chandra Observations of GRB000210 X-ray Afterglow
  84. IPN triangulation of GRB000210
  85. GRB 000201: TAROT optical observations
  86. GRB 000131 Optical Observations
  87. GRB000126 Optical Observations
  88. BATSE GRB trigger criteria changed
  89. GRB 991208, radio observations
  90. BATSE+IPN location of GRB000131
  91. IPN localization of GRB000131
  92. GRB 000126, optical observations
  93. GRB000126, optical observations
  94. BATSE location of GRB000126
  95. IPN localization of GRB000126
  96. GRB 000115 Optical observations
  97. BATSE Observations of GRB000115
  98. Second RXTE Observation of GRB 000115
  99. GRB991216, UBVRIJHK field photometry
  100. Single IPN error box for GRB991229

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