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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"

35433 results found.

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

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