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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"

41586 results found.

  1. possible optical counterpart of GRB 000630
  2. IPN triangulation of GRB000630
  3. GRB 000623, optical observations
  4. GRB 000620, optical observations
  5. GRB000418, HST/STIS Observations
  6. GRB990123: Late-time HST/STIS observations of the host
  7. GRB 990506, HST/STIS Observations of the Host Galaxy
  8. GRB000623
  9. GRB 000620: J-band observations
  10. GRB000620, optical observations
  11. GRB000615: H-band observations
  12. GRB990308, HST/STIS observations of the host galaxy
  13. GRB000620 Optical observations
  14. IPN annulus for GRB000620
  15. GRB000620: BeppoSAX WFC and GRBM detection
  16. GRB000615, Radio observations
  17. GRB000607, optical observations
  18. GRB 000615: NIR further observations
  19. BeppoSAX ALERT: GRB000620
  20. GRB000620: BeppoSAX Alert
  21. GRB990123, HST/STIS observations of the host galaxy
  22. GRB000616 optical observations
  23. GRB 000615, near-infrared observations
  24. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  25. GRB 000615: NIR observations
  26. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  27. GRB980425, HST/STIS observations of the host galaxy
  28. GRB000615: BeppoSAX GRB Alert
  29. The Hosts of GRB 980703 and GRB 971214
  30. GRB 000301C: Further Late-Time HST/STIS observations
  31. GRB000528: follow-up X-ray measurements and update of IPN annulus
  32. Optical Follow-up of GRB000529 Error Box
  33. GRB980519, HST/STIS observations of the host galaxy
  34. GRB000607, Radio Observations
  35. BeppoSAX X-ray transient/possible GRB000608
  36. GRB000604 optical non-detection
  37. GRB000604 - Optical observations
  38. GRB000607, A SHORT, HARD BURST
  39. GRB000604, optical observations
  40. GRB000528, optical observations at ESO
  41. GRB 000604 optical observations
  42. GRB 000418: Detection of the Host Galaxy
  43. GRB000604, optical observations, comparison with DPOSS
  44. GRB000604 [IPN Position]
  45. GRB000528, Radio Observations
  46. X-ray Afterglow of GRB 000529
  47. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  48. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  49. GRB000529: Optical Observations
  50. IPN localization and time history of GRB000528
  51. New IPN localization of GRB000529
  52. GRB000519: Optical observations
  53. GRB000529: BeppoSAX WFC position
  54. GRB000528: BeppoSAX GRBM observations
  55. GRB 000528 Optical Observations
  56. GRB000519, BVRI field photometry
  57. IPN triangulation of GRB000519
  58. IPN triangulation of GRB000516
  59. Re: GRB000508B : Optical observations
  60. GRB 000418, Optical observation
  61. GRB000508B, BVR field photometry
  62. Possible GRB-related phenomenon
  63. RXTE/ASM and IPN localization of GRB 000508B
  64. GRB000424, UBVRI field photometry
  65. GRB 000424 Optical Observations
  66. GRB000418, UBVRI field photometry update
  67. The redshift of GRB 000418
  68. GRB000424, optical observations
  69. GRB 000429, optical observation
  70. GRB 000429, UBVRI field photometry
  71. IPN localization of GRB000429
  72. GRB 000418, UBVRI field photometry
  73. GRB000418, Radio detection
  74. GRB000418, K'-band photometry
  75. GRB 000418, optical observation
  76. GRB000424 Optical Observations
  77. GRB 000418, Optical Observation
  78. GRB000424, optical observations
  79. GRB 000424, Optical Observations
  80. GRB 000418, Optical Observation
  81. GRB000418, near-infrared observations
  82. BeppoSAX GRB000424
  83. Correction to IPN error box for GRB000419
  84. IPN error box for GRB000418
  85. GRB000419 [IPN Position]
  86. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  87. GRB000416 BRJK observations
  88. 1SAXJ1715.0-7134 refined position
  89. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  90. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  91. Budget cuts in BeppoSAX operations: impact on GRB observations
  92. GRB 000408, optical observations
  93. Refined IPN error box for GRB000408
  94. GRB 991208, UBVRI field photometry
  95. GRB000301c results
  96. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  97. GRB000408 [IPN Position]
  98. GRB000326 Optical Observations
  99. GRB000301C - Addendum to GCN 623
  100. GRB000301C - R magnitude lower limit

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