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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"

36144 results found.

  1. GRB000519, BVRI field photometry
  2. IPN triangulation of GRB000519
  3. IPN triangulation of GRB000516
  4. Re: GRB000508B : Optical observations
  5. GRB 000418, Optical observation
  6. GRB000508B, optical photometry
  7. GRB000508B, BVR field photometry
  8. Possible GRB-related phenomenon
  9. RXTE/ASM and IPN localization of GRB 000508B
  10. GRB000424, UBVRI field photometry
  11. GRB 000424 Optical Observations
  12. GRB000418, UBVRI field photometry update
  13. The redshift of GRB 000418
  14. GRB 000429, optical observation
  15. GRB 000429, UBVRI field photometry
  16. IPN localization of GRB000429
  17. GRB 000418, UBVRI field photometry
  18. GRB000418, K'-band photometry
  19. GRB 000418, Optical Observation
  20. GRB 000418, optical observation
  21. GRB000424 Optical Observations
  22. GRB 000418, Optical Observation
  23. GRB 000424, Optical Observations
  24. GRB 000418, Optical Observation
  25. GRB000418, near-infrared observations
  26. Correction to IPN error box for GRB000419
  27. IPN error box for GRB000418
  28. GRB000419 [IPN Position]
  29. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  30. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  31. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  32. Budget cuts in BeppoSAX operations: impact on GRB observations
  33. GRB 000408, optical observations
  34. Refined IPN error box for GRB000408
  35. GRB 991208, UBVRI field photometry
  36. GRB000301c results
  37. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  38. GRB000408 [IPN Position]
  39. GRB000326 Optical Observations
  40. GRB000301C - Addendum to GCN 623
  41. GRB000301C - R magnitude lower limit
  42. GRB 000323, optical observations
  43. GRB 000326: Optical Observations
  44. GRB000326, Radio observations
  45. GRB000326 [IPN Position]
  46. GRB 000307 optical observations
  47. GRB000323 [IPN Position]
  48. GRB000315 [IPN Positions]
  49. GRB 000313 - optical transient in the BATSE error box
  50. GRB000301C - B and R photometry
  51. GRB000301C - R photometry
  52. GRB 000307, Optical Observations
  53. GRB 000307, BVRI Field Photometry
  54. GRB 000301C: Optical Spectrum and Redshift
  55. GRB 000301C: Optical Spectrum and Redshift
  56. GRB 000301C: A Precise Redshift Determination
  57. GRB 000301C, Optical Observation
  58. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  59. GRB 000301C: HST/STIS CCD Imaging of the field
  60. IPN error box for GRB000307
  61. GRB 000301c: K' observations
  62. GRB000301C, optical R-band observations
  63. GRB000301c - R photometry and nearby faint source confirmation
  64. GRB 000301C, Optical Observation
  65. GRB 000301c: K' observations
  66. GRB 000301C Optical Observations
  67. GRB 000301C: K' Observations
  68. GRB000301C - Host galaxy not detected in R (?)
  69. Optical observations of GRB000301c
  70. GRB000301C optical observations
  71. GRB 000301c near-IR observations
  72. GRB 000301C, Optical Color
  73. GRB000301C, Optical Spectroscopy
  74. GRB 000301C, UBVRI field photometry
  75. GRB 000301C, Optical Observation
  76. GRB000301C 250 GHz detection
  77. GRB 000301C R-band observation
  78. GRB 000301C, Optical Observation
  79. GRB000301C, near-infrared observations (JHK' photometry)
  80. GRB 000301C: OT confirmed
  81. GRB000301c optical observations
  82. GRB 000301A, Radio Observations
  83. GRB000301C, optical observations
  84. GRB000301c, near-infrared observations
  85. GRB000301C
  86. GRB 000301C : Optical Candidate
  87. GRB000301C: RXTE/ASM and IPN localizations
  88. GRB000226 [IPN Position]
  89. HST Observations of GRB 990712
  90. GRB 000214 near-IR observations
  91. GRB 000115 Optical observations
  92. GRB 000214, Radio Observations
  93. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  94. GRB 000115, BVRI field photometry
  95. IPN annulus for GRB000214
  96. BATSE GRB trigger criterion changed
  97. GRB000210 X-ray afterglow
  98. GRB000214: X-ray afterglow candidate
  99. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  100. GRB 000210: BATSE Observations

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