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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"

36131 results found.

  1. GRB 000429, optical observation
  2. GRB 000429, UBVRI field photometry
  3. IPN localization of GRB000429
  4. GRB 000418, UBVRI field photometry
  5. GRB000418, K'-band photometry
  6. GRB 000418, Optical Observation
  7. GRB 000418, optical observation
  8. GRB000424 Optical Observations
  9. GRB 000418, Optical Observation
  10. GRB 000424, Optical Observations
  11. GRB 000418, Optical Observation
  12. GRB000418, near-infrared observations
  13. Correction to IPN error box for GRB000419
  14. IPN error box for GRB000418
  15. GRB000419 [IPN Position]
  16. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  17. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  18. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  19. Budget cuts in BeppoSAX operations: impact on GRB observations
  20. GRB 000408, optical observations
  21. Refined IPN error box for GRB000408
  22. GRB 991208, UBVRI field photometry
  23. GRB000301c results
  24. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  25. GRB000408 [IPN Position]
  26. GRB000326 Optical Observations
  27. GRB000301C - Addendum to GCN 623
  28. GRB000301C - R magnitude lower limit
  29. GRB 000323, optical observations
  30. GRB 000326: Optical Observations
  31. GRB000326, Radio observations
  32. GRB000326 [IPN Position]
  33. GRB 000307 optical observations
  34. GRB000323 [IPN Position]
  35. GRB000315 [IPN Positions]
  36. GRB 000313 - optical transient in the BATSE error box
  37. GRB000301C - B and R photometry
  38. GRB000301C - R photometry
  39. GRB 000307, Optical Observations
  40. GRB 000307, BVRI Field Photometry
  41. GRB 000301C: Optical Spectrum and Redshift
  42. GRB 000301C: Optical Spectrum and Redshift
  43. GRB 000301C: A Precise Redshift Determination
  44. GRB 000301C, Optical Observation
  45. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  46. GRB 000301C: HST/STIS CCD Imaging of the field
  47. IPN error box for GRB000307
  48. GRB 000301c: K' observations
  49. GRB000301C, optical R-band observations
  50. GRB000301c - R photometry and nearby faint source confirmation
  51. GRB 000301C, Optical Observation
  52. GRB 000301c: K' observations
  53. GRB 000301C Optical Observations
  54. GRB 000301C: K' Observations
  55. GRB000301C - Host galaxy not detected in R (?)
  56. Optical observations of GRB000301c
  57. GRB000301C optical observations
  58. GRB 000301c near-IR observations
  59. GRB 000301C, Optical Color
  60. GRB000301C, Optical Spectroscopy
  61. GRB 000301C, UBVRI field photometry
  62. GRB 000301C, Optical Observation
  63. GRB000301C 250 GHz detection
  64. GRB 000301C R-band observation
  65. GRB 000301C, Optical Observation
  66. GRB000301C, near-infrared observations (JHK' photometry)
  67. GRB 000301C: OT confirmed
  68. GRB000301c optical observations
  69. GRB 000301A, Radio Observations
  70. GRB000301C, optical observations
  71. GRB000301c, near-infrared observations
  72. GRB000301C
  73. GRB 000301C : Optical Candidate
  74. GRB000301C: RXTE/ASM and IPN localizations
  75. GRB000226 [IPN Position]
  76. HST Observations of GRB 990712
  77. GRB 000214 near-IR observations
  78. GRB 000115 Optical observations
  79. GRB 000214, Radio Observations
  80. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  81. GRB 000115, BVRI field photometry
  82. IPN annulus for GRB000214
  83. BATSE GRB trigger criterion changed
  84. GRB000210 X-ray afterglow
  85. GRB000214: X-ray afterglow candidate
  86. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  87. GRB 000210: BATSE Observations
  88. Optical observations of the Chandra X-ray source for GRB000210
  89. Chandra Observations of GRB000210 X-ray Afterglow
  90. IPN triangulation of GRB000210
  91. GRB 000201: TAROT optical observations
  92. GRB 000131 Optical Observations
  93. GRB000126 Optical Observations
  94. BATSE GRB trigger criteria changed
  95. GRB 991208, radio observations
  96. BATSE+IPN location of GRB000131
  97. IPN localization of GRB000131
  98. GRB 000126, optical observations
  99. GRB000126, optical observations
  100. BATSE location of GRB000126

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