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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"

37524 results found.

  1. GRB 000418, UBVRI field photometry
  2. GRB000418, K'-band photometry
  3. GRB 000418, Optical Observation
  4. GRB 000418, optical observation
  5. GRB000424 Optical Observations
  6. GRB 000418, Optical Observation
  7. GRB 000424, Optical Observations
  8. GRB 000418, Optical Observation
  9. GRB000418, near-infrared observations
  10. Correction to IPN error box for GRB000419
  11. IPN error box for GRB000418
  12. GRB000419 [IPN Position]
  13. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  14. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  15. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  16. Budget cuts in BeppoSAX operations: impact on GRB observations
  17. GRB 000408, optical observations
  18. Refined IPN error box for GRB000408
  19. GRB 991208, UBVRI field photometry
  20. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  21. GRB000408 [IPN Position]
  22. GRB000326 Optical Observations
  23. GRB000301C - Addendum to GCN 623
  24. GRB000301C - R magnitude lower limit
  25. GRB 000323, optical observations
  26. GRB 000326: Optical Observations
  27. GRB000326, Radio observations
  28. GRB000326 [IPN Position]
  29. GRB 000307 optical observations
  30. GRB000323 [IPN Position]
  31. GRB000315 [IPN Positions]
  32. GRB 000313 - optical transient in the BATSE error box
  33. GRB000301C - B and R photometry
  34. GRB000301C - R photometry
  35. GRB 000307, Optical Observations
  36. GRB 000307, BVRI Field Photometry
  37. GRB 000301C: Optical Spectrum and Redshift
  38. GRB 000301C: Optical Spectrum and Redshift
  39. GRB 000301C: A Precise Redshift Determination
  40. GRB 000301C, Optical Observation
  41. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  42. GRB 000301C: HST/STIS CCD Imaging of the field
  43. IPN error box for GRB000307
  44. GRB 000301c: K' observations
  45. GRB000301C, optical R-band observations
  46. GRB000301c - R photometry and nearby faint source confirmation
  47. GRB 000301C, Optical Observation
  48. GRB 000301c: K' observations
  49. GRB 000301C Optical Observations
  50. GRB 000301C: K' Observations
  51. GRB000301C - Host galaxy not detected in R (?)
  52. GRB000301C optical observations
  53. GRB 000301c near-IR observations
  54. GRB 000301C, Optical Color
  55. GRB000301C, Optical Spectroscopy
  56. GRB 000301C, UBVRI field photometry
  57. GRB 000301C, Optical Observation
  58. GRB000301C 250 GHz detection
  59. GRB 000301C R-band observation
  60. GRB 000301C, Optical Observation
  61. GRB000301C, near-infrared observations (JHK' photometry)
  62. GRB 000301C: OT confirmed
  63. GRB000301c optical observations
  64. GRB 000301A, Radio Observations
  65. GRB000301C, optical observations
  66. GRB000301c, near-infrared observations
  67. GRB000301C
  68. GRB 000301C : Optical Candidate
  69. GRB000301C: RXTE/ASM and IPN localizations
  70. GRB000226 [IPN Position]
  71. HST Observations of GRB 990712
  72. GRB 000214 near-IR observations
  73. GRB 000115 Optical observations
  74. GRB 000214, Radio Observations
  75. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  76. GRB 000115, BVRI field photometry
  77. IPN annulus for GRB000214
  78. BATSE GRB trigger criterion changed
  79. GRB000210 X-ray afterglow
  80. GRB000214: X-ray afterglow candidate
  81. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  82. GRB 000210: BATSE Observations
  83. Optical observations of the Chandra X-ray source for GRB000210
  84. Chandra Observations of GRB000210 X-ray Afterglow
  85. IPN triangulation of GRB000210
  86. GRB 000201: TAROT optical observations
  87. GRB 000131 Optical Observations
  88. GRB000126 Optical Observations
  89. BATSE GRB trigger criteria changed
  90. GRB 991208, radio observations
  91. BATSE+IPN location of GRB000131
  92. IPN localization of GRB000131
  93. GRB 000126, optical observations
  94. GRB000126, optical observations
  95. BATSE location of GRB000126
  96. IPN localization of GRB000126
  97. GRB 000115 Optical observations
  98. BATSE Observations of GRB000115
  99. Second RXTE Observation of GRB 000115
  100. GRB991216, UBVRIJHK field photometry

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