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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"

35963 results found.

  1. GRB980425, HST/STIS observations of the host galaxy
  2. GRB000615: BeppoSAX GRB Alert
  3. The Hosts of GRB 980703 and GRB 971214
  4. GRB 000301C: Further Late-Time HST/STIS observations
  5. GRB000528: follow-up X-ray measurements and update of IPN annulus
  6. GRB980519, HST/STIS observations of the host galaxy
  7. GRB000607, Radio Observations
  8. GRB000604 - Optical observations
  9. GRB000607, A SHORT, HARD BURST
  10. GRB000604, optical observations
  11. GRB000528, optical observations at ESO
  12. GRB 000604 optical observations
  13. GRB 000418: Detection of the Host Galaxy
  14. GRB000604, optical observations, comparison with DPOSS
  15. GRB000604 [IPN Position]
  16. X-ray Afterglow of GRB 000529
  17. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  18. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  19. IPN localization and time history of GRB000528
  20. New IPN localization of GRB000529
  21. GRB 000528 - WFC measurements
  22. GRB000528: BeppoSAX GRBM observations
  23. GRB 000528 Optical Observations
  24. GRB000519, BVRI field photometry
  25. IPN triangulation of GRB000519
  26. IPN triangulation of GRB000516
  27. Re: GRB000508B : Optical observations
  28. GRB 000418, Optical observation
  29. GRB000508B, optical photometry
  30. GRB000508B, BVR field photometry
  31. Possible GRB-related phenomenon
  32. RXTE/ASM and IPN localization of GRB 000508B
  33. GRB000424, UBVRI field photometry
  34. GRB 000424 Optical Observations
  35. GRB000418, UBVRI field photometry update
  36. The redshift of GRB 000418
  37. GRB 000429, optical observation
  38. GRB 000429, UBVRI field photometry
  39. IPN localization of GRB000429
  40. GRB 000418, UBVRI field photometry
  41. GRB000418, K'-band photometry
  42. GRB 000418, Optical Observation
  43. GRB 000418, optical observation
  44. GRB000424 Optical Observations
  45. GRB 000418, Optical Observation
  46. GRB 000424, Optical Observations
  47. GRB 000418, Optical Observation
  48. GRB000418, near-infrared observations
  49. Correction to IPN error box for GRB000419
  50. IPN error box for GRB000418
  51. GRB000419 [IPN Position]
  52. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  53. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  54. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  55. Budget cuts in BeppoSAX operations: impact on GRB observations
  56. GRB 000408, optical observations
  57. Refined IPN error box for GRB000408
  58. GRB 991208, UBVRI field photometry
  59. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  60. GRB000408 [IPN Position]
  61. GRB000326 Optical Observations
  62. GRB000301C - Addendum to GCN 623
  63. GRB000301C - R magnitude lower limit
  64. GRB 000323, optical observations
  65. GRB 000326: Optical Observations
  66. GRB000326, Radio observations
  67. GRB000326 [IPN Position]
  68. GRB 000307 optical observations
  69. GRB000323 [IPN Position]
  70. GRB000315 [IPN Positions]
  71. GRB 000313 - optical transient in the BATSE error box
  72. GRB000301C - B and R photometry
  73. GRB000301C - R photometry
  74. GRB 000307, Optical Observations
  75. GRB 000307, BVRI Field Photometry
  76. GRB 000301C: Optical Spectrum and Redshift
  77. GRB 000301C: Optical Spectrum and Redshift
  78. GRB 000301C: A Precise Redshift Determination
  79. GRB 000301C, Optical Observation
  80. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  81. GRB 000301C: HST/STIS CCD Imaging of the field
  82. IPN error box for GRB000307
  83. GRB 000301c: K' observations
  84. GRB000301C, optical R-band observations
  85. GRB000301c - R photometry and nearby faint source confirmation
  86. GRB 000301C, Optical Observation
  87. GRB 000301c: K' observations
  88. GRB 000301C Optical Observations
  89. GRB 000301C: K' Observations
  90. GRB000301C - Host galaxy not detected in R (?)
  91. GRB000301C optical observations
  92. GRB 000301c near-IR observations
  93. GRB 000301C, Optical Color
  94. GRB000301C, Optical Spectroscopy
  95. GRB 000301C, UBVRI field photometry
  96. GRB 000301C, Optical Observation
  97. GRB000301C 250 GHz detection
  98. GRB 000301C R-band observation
  99. GRB 000301C, Optical Observation
  100. GRB000301C, near-infrared observations (JHK' photometry)

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