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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"

36141 results found.

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

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