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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"

35946 results found.

  1. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  2. IPN localization and time history of GRB000528
  3. New IPN localization of GRB000529
  4. GRB 000528 - WFC measurements
  5. GRB000528: BeppoSAX GRBM observations
  6. GRB 000528 Optical Observations
  7. GRB000519, BVRI field photometry
  8. IPN triangulation of GRB000519
  9. IPN triangulation of GRB000516
  10. Re: GRB000508B : Optical observations
  11. GRB 000418, Optical observation
  12. GRB000508B, optical photometry
  13. GRB000508B, BVR field photometry
  14. Possible GRB-related phenomenon
  15. RXTE/ASM and IPN localization of GRB 000508B
  16. GRB000424, UBVRI field photometry
  17. GRB 000424 Optical Observations
  18. GRB000418, UBVRI field photometry update
  19. The redshift of GRB 000418
  20. GRB 000429, optical observation
  21. GRB 000429, UBVRI field photometry
  22. IPN localization of GRB000429
  23. GRB 000418, UBVRI field photometry
  24. GRB000418, K'-band photometry
  25. GRB 000418, Optical Observation
  26. GRB 000418, optical observation
  27. GRB000424 Optical Observations
  28. GRB 000418, Optical Observation
  29. GRB 000424, Optical Observations
  30. GRB 000418, Optical Observation
  31. GRB000418, near-infrared observations
  32. Correction to IPN error box for GRB000419
  33. IPN error box for GRB000418
  34. GRB000419 [IPN Position]
  35. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  36. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  37. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  38. Budget cuts in BeppoSAX operations: impact on GRB observations
  39. GRB 000408, optical observations
  40. Refined IPN error box for GRB000408
  41. GRB 991208, UBVRI field photometry
  42. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  43. GRB000408 [IPN Position]
  44. GRB000326 Optical Observations
  45. GRB000301C - Addendum to GCN 623
  46. GRB000301C - R magnitude lower limit
  47. GRB 000323, optical observations
  48. GRB 000326: Optical Observations
  49. GRB000326, Radio observations
  50. GRB000326 [IPN Position]
  51. GRB 000307 optical observations
  52. GRB000323 [IPN Position]
  53. GRB000315 [IPN Positions]
  54. GRB 000313 - optical transient in the BATSE error box
  55. GRB000301C - B and R photometry
  56. GRB000301C - R photometry
  57. GRB 000307, Optical Observations
  58. GRB 000307, BVRI Field Photometry
  59. GRB 000301C: Optical Spectrum and Redshift
  60. GRB 000301C: Optical Spectrum and Redshift
  61. GRB 000301C: A Precise Redshift Determination
  62. GRB 000301C, Optical Observation
  63. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  64. GRB 000301C: HST/STIS CCD Imaging of the field
  65. IPN error box for GRB000307
  66. GRB 000301c: K' observations
  67. GRB000301C, optical R-band observations
  68. GRB000301c - R photometry and nearby faint source confirmation
  69. GRB 000301C, Optical Observation
  70. GRB 000301c: K' observations
  71. GRB 000301C Optical Observations
  72. GRB 000301C: K' Observations
  73. GRB000301C - Host galaxy not detected in R (?)
  74. GRB000301C optical observations
  75. GRB 000301c near-IR observations
  76. GRB 000301C, Optical Color
  77. GRB000301C, Optical Spectroscopy
  78. GRB 000301C, UBVRI field photometry
  79. GRB 000301C, Optical Observation
  80. GRB000301C 250 GHz detection
  81. GRB 000301C R-band observation
  82. GRB 000301C, Optical Observation
  83. GRB000301C, near-infrared observations (JHK' photometry)
  84. GRB 000301C: OT confirmed
  85. GRB000301c optical observations
  86. GRB 000301A, Radio Observations
  87. GRB000301C, optical observations
  88. GRB000301c, near-infrared observations
  89. GRB000301C
  90. GRB 000301C : Optical Candidate
  91. GRB000301C: RXTE/ASM and IPN localizations
  92. GRB000226 [IPN Position]
  93. HST Observations of GRB 990712
  94. GRB 000214 near-IR observations
  95. GRB 000115 Optical observations
  96. GRB 000214, Radio Observations
  97. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  98. GRB 000115, BVRI field photometry
  99. IPN annulus for GRB000214
  100. BATSE GRB trigger criterion changed

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