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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"

37514 results found.

  1. IPN error box for GRB000418
  2. GRB000419 [IPN Position]
  3. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  4. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  5. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  6. Budget cuts in BeppoSAX operations: impact on GRB observations
  7. GRB 000408, optical observations
  8. Refined IPN error box for GRB000408
  9. GRB 991208, UBVRI field photometry
  10. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  11. GRB000408 [IPN Position]
  12. GRB000326 Optical Observations
  13. GRB000301C - Addendum to GCN 623
  14. GRB000301C - R magnitude lower limit
  15. GRB 000323, optical observations
  16. GRB 000326: Optical Observations
  17. GRB000326, Radio observations
  18. GRB000326 [IPN Position]
  19. GRB 000307 optical observations
  20. GRB000323 [IPN Position]
  21. GRB000315 [IPN Positions]
  22. GRB 000313 - optical transient in the BATSE error box
  23. GRB000301C - B and R photometry
  24. GRB000301C - R photometry
  25. GRB 000307, Optical Observations
  26. GRB 000307, BVRI Field Photometry
  27. GRB 000301C: Optical Spectrum and Redshift
  28. GRB 000301C: Optical Spectrum and Redshift
  29. GRB 000301C: A Precise Redshift Determination
  30. GRB 000301C, Optical Observation
  31. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  32. GRB 000301C: HST/STIS CCD Imaging of the field
  33. IPN error box for GRB000307
  34. GRB 000301c: K' observations
  35. GRB000301C, optical R-band observations
  36. GRB000301c - R photometry and nearby faint source confirmation
  37. GRB 000301C, Optical Observation
  38. GRB 000301c: K' observations
  39. GRB 000301C Optical Observations
  40. GRB 000301C: K' Observations
  41. GRB000301C - Host galaxy not detected in R (?)
  42. GRB000301C optical observations
  43. GRB 000301c near-IR observations
  44. GRB 000301C, Optical Color
  45. GRB000301C, Optical Spectroscopy
  46. GRB 000301C, UBVRI field photometry
  47. GRB 000301C, Optical Observation
  48. GRB000301C 250 GHz detection
  49. GRB 000301C R-band observation
  50. GRB 000301C, Optical Observation
  51. GRB000301C, near-infrared observations (JHK' photometry)
  52. GRB 000301C: OT confirmed
  53. GRB000301c optical observations
  54. GRB 000301A, Radio Observations
  55. GRB000301C, optical observations
  56. GRB000301c, near-infrared observations
  57. GRB000301C
  58. GRB 000301C : Optical Candidate
  59. GRB000301C: RXTE/ASM and IPN localizations
  60. GRB000226 [IPN Position]
  61. HST Observations of GRB 990712
  62. GRB 000214 near-IR observations
  63. GRB 000115 Optical observations
  64. GRB 000214, Radio Observations
  65. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  66. GRB 000115, BVRI field photometry
  67. IPN annulus for GRB000214
  68. BATSE GRB trigger criterion changed
  69. GRB000210 X-ray afterglow
  70. GRB000214: X-ray afterglow candidate
  71. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  72. GRB 000210: BATSE Observations
  73. Optical observations of the Chandra X-ray source for GRB000210
  74. Chandra Observations of GRB000210 X-ray Afterglow
  75. IPN triangulation of GRB000210
  76. GRB 000201: TAROT optical observations
  77. GRB 000131 Optical Observations
  78. GRB000126 Optical Observations
  79. BATSE GRB trigger criteria changed
  80. GRB 991208, radio observations
  81. BATSE+IPN location of GRB000131
  82. IPN localization of GRB000131
  83. GRB 000126, optical observations
  84. GRB000126, optical observations
  85. BATSE location of GRB000126
  86. IPN localization of GRB000126
  87. GRB 000115 Optical observations
  88. BATSE Observations of GRB000115
  89. Second RXTE Observation of GRB 000115
  90. GRB991216, UBVRIJHK field photometry
  91. Single IPN error box for GRB991229
  92. GRB 991216 VLBA Observations
  93. BEPPOSAX GRBM Localization of GRB991226
  94. IPN error boxes for GRB991229
  95. GRB 991216: J band spectrophotometry
  96. GRB 991216: Detection of the Host and/or Absorber Galaxy
  97. IPN localization of GRB991226
  98. Single IPN error box for GRB991221
  99. IPN error boxes for GRB991221
  100. GRB 991216 RXTE ASM Observations

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