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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"

35260 results found.

  1. GRB 000301C: Further Late-Time HST/STIS observations
  2. GRB000528: follow-up X-ray measurements and update of IPN annulus
  3. GRB980519, HST/STIS observations of the host galaxy
  4. GRB000607, Radio Observations
  5. GRB000604 - Optical observations
  6. GRB000607, A SHORT, HARD BURST
  7. GRB000604, optical observations
  8. GRB000528, optical observations at ESO
  9. GRB 000604 optical observations
  10. GRB 000418: Detection of the Host Galaxy
  11. GRB000604, optical observations, comparison with DPOSS
  12. GRB000604 [IPN Position]
  13. X-ray Afterglow of GRB 000529
  14. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  15. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  16. IPN localization and time history of GRB000528
  17. New IPN localization of GRB000529
  18. GRB 000528 - WFC measurements
  19. GRB000528: BeppoSAX GRBM observations
  20. GRB 000528 Optical Observations
  21. GRB000519, BVRI field photometry
  22. IPN triangulation of GRB000519
  23. IPN triangulation of GRB000516
  24. Re: GRB000508B : Optical observations
  25. GRB 000418, Optical observation
  26. GRB000508B, optical photometry
  27. GRB000508B, BVR field photometry
  28. Possible GRB-related phenomenon
  29. RXTE/ASM and IPN localization of GRB 000508B
  30. GRB000424, UBVRI field photometry
  31. GRB 000424 Optical Observations
  32. GRB000418, UBVRI field photometry update
  33. The redshift of GRB 000418
  34. GRB 000429, optical observation
  35. GRB 000429, UBVRI field photometry
  36. IPN localization of GRB000429
  37. GRB 000418, UBVRI field photometry
  38. GRB000418, K'-band photometry
  39. GRB 000418, Optical Observation
  40. GRB 000418, optical observation
  41. GRB000424 Optical Observations
  42. GRB 000418, Optical Observation
  43. GRB 000424, Optical Observations
  44. GRB 000418, Optical Observation
  45. GRB000418, near-infrared observations
  46. Correction to IPN error box for GRB000419
  47. IPN error box for GRB000418
  48. GRB000419 [IPN Position]
  49. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  50. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  51. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  52. Budget cuts in BeppoSAX operations: impact on GRB observations
  53. GRB 000408, optical observations
  54. Refined IPN error box for GRB000408
  55. GRB 991208, UBVRI field photometry
  56. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  57. GRB000408 [IPN Position]
  58. GRB000326 Optical Observations
  59. GRB000301C - Addendum to GCN 623
  60. GRB000301C - R magnitude lower limit
  61. GRB 000323, optical observations
  62. GRB 000326: Optical Observations
  63. GRB000326, Radio observations
  64. GRB000326 [IPN Position]
  65. GRB 000307 optical observations
  66. GRB000323 [IPN Position]
  67. GRB000315 [IPN Positions]
  68. GRB 000313 - optical transient in the BATSE error box
  69. GRB000301C - B and R photometry
  70. GRB000301C - R photometry
  71. GRB 000307, Optical Observations
  72. GRB 000307, BVRI Field Photometry
  73. GRB 000301C: Optical Spectrum and Redshift
  74. GRB 000301C: Optical Spectrum and Redshift
  75. GRB 000301C: A Precise Redshift Determination
  76. GRB 000301C, Optical Observation
  77. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  78. GRB 000301C: HST/STIS CCD Imaging of the field
  79. IPN error box for GRB000307
  80. GRB 000301c: K' observations
  81. GRB000301C, optical R-band observations
  82. GRB000301c - R photometry and nearby faint source confirmation
  83. GRB 000301C, Optical Observation
  84. GRB 000301c: K' observations
  85. GRB 000301C Optical Observations
  86. GRB 000301C: K' Observations
  87. GRB000301C - Host galaxy not detected in R (?)
  88. GRB000301C optical observations
  89. GRB 000301c near-IR observations
  90. GRB 000301C, Optical Color
  91. GRB000301C, Optical Spectroscopy
  92. GRB 000301C, UBVRI field photometry
  93. GRB 000301C, Optical Observation
  94. GRB000301C 250 GHz detection
  95. GRB 000301C R-band observation
  96. GRB 000301C, Optical Observation
  97. GRB000301C, near-infrared observations (JHK' photometry)
  98. GRB 000301C: OT confirmed
  99. GRB000301c optical observations
  100. GRB 000301A, Radio Observations

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