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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"

37954 results found.

  1. GRB000604, optical observations
  2. GRB000528, optical observations at ESO
  3. GRB 000604 optical observations
  4. GRB 000418: Detection of the Host Galaxy
  5. GRB000604, optical observations, comparison with DPOSS
  6. GRB000604 [IPN Position]
  7. X-ray Afterglow of GRB 000529
  8. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  9. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  10. IPN localization and time history of GRB000528
  11. New IPN localization of GRB000529
  12. GRB 000528 - WFC measurements
  13. GRB000528: BeppoSAX GRBM observations
  14. GRB 000528 Optical Observations
  15. GRB000519, BVRI field photometry
  16. IPN triangulation of GRB000519
  17. IPN triangulation of GRB000516
  18. Re: GRB000508B : Optical observations
  19. GRB 000418, Optical observation
  20. GRB000508B, optical photometry
  21. GRB000508B, BVR field photometry
  22. Possible GRB-related phenomenon
  23. RXTE/ASM and IPN localization of GRB 000508B
  24. GRB000424, UBVRI field photometry
  25. GRB 000424 Optical Observations
  26. GRB000418, UBVRI field photometry update
  27. The redshift of GRB 000418
  28. GRB 000429, optical observation
  29. GRB 000429, UBVRI field photometry
  30. IPN localization of GRB000429
  31. GRB 000418, UBVRI field photometry
  32. GRB000418, K'-band photometry
  33. GRB 000418, Optical Observation
  34. GRB 000418, optical observation
  35. GRB000424 Optical Observations
  36. GRB 000418, Optical Observation
  37. GRB 000424, Optical Observations
  38. GRB 000418, Optical Observation
  39. GRB000418, near-infrared observations
  40. Correction to IPN error box for GRB000419
  41. IPN error box for GRB000418
  42. GRB000419 [IPN Position]
  43. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  44. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  45. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  46. Budget cuts in BeppoSAX operations: impact on GRB observations
  47. GRB 000408, optical observations
  48. Refined IPN error box for GRB000408
  49. GRB 991208, UBVRI field photometry
  50. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  51. GRB000408 [IPN Position]
  52. GRB000326 Optical Observations
  53. GRB000301C - Addendum to GCN 623
  54. GRB000301C - R magnitude lower limit
  55. GRB 000323, optical observations
  56. GRB 000326: Optical Observations
  57. GRB000326, Radio observations
  58. GRB000326 [IPN Position]
  59. GRB 000307 optical observations
  60. GRB000323 [IPN Position]
  61. GRB000315 [IPN Positions]
  62. GRB 000313 - optical transient in the BATSE error box
  63. GRB000301C - B and R photometry
  64. GRB000301C - R photometry
  65. GRB 000307, Optical Observations
  66. GRB 000307, BVRI Field Photometry
  67. GRB 000301C: Optical Spectrum and Redshift
  68. GRB 000301C: Optical Spectrum and Redshift
  69. GRB 000301C: A Precise Redshift Determination
  70. GRB 000301C, Optical Observation
  71. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  72. GRB 000301C: HST/STIS CCD Imaging of the field
  73. IPN error box for GRB000307
  74. GRB 000301c: K' observations
  75. GRB000301C, optical R-band observations
  76. GRB000301c - R photometry and nearby faint source confirmation
  77. GRB 000301C, Optical Observation
  78. GRB 000301c: K' observations
  79. GRB 000301C Optical Observations
  80. GRB 000301C: K' Observations
  81. GRB000301C - Host galaxy not detected in R (?)
  82. GRB000301C optical observations
  83. GRB 000301c near-IR observations
  84. GRB 000301C, Optical Color
  85. GRB000301C, Optical Spectroscopy
  86. GRB 000301C, UBVRI field photometry
  87. GRB 000301C, Optical Observation
  88. GRB000301C 250 GHz detection
  89. GRB 000301C R-band observation
  90. GRB 000301C, Optical Observation
  91. GRB000301C, near-infrared observations (JHK' photometry)
  92. GRB 000301C: OT confirmed
  93. GRB000301c optical observations
  94. GRB 000301A, Radio Observations
  95. GRB000301C, optical observations
  96. GRB000301c, near-infrared observations
  97. GRB000301C
  98. GRB 000301C : Optical Candidate
  99. GRB000301C: RXTE/ASM and IPN localizations
  100. GRB000226 [IPN Position]

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