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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"
  1. GRB000615: H-band observations
  2. GRB990308, HST/STIS observations of the host galaxy
  3. GRB000620 - Optical observations
  4. GRB000620 Optical observations
  5. IPN annulus for GRB000620
  6. GRB000620: BeppoSAX WFC and GRBM detection
  7. GRB000615, Radio observations
  8. GRB000607, optical observations
  9. GRB 000615: NIR further observations
  10. GRB000620: refined BeppoSAX/WFC coordinates
  11. BeppoSAX ALERT: GRB000620
  12. GRB000620: BeppoSAX Alert
  13. GRB990123, HST/STIS observations of the host galaxy
  14. GRB000616 optical observations
  15. GRB 000615, near-infrared observations
  16. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  17. GRB000616 [IPN Position]
  18. GRB000615B [IPN Position]
  19. GRB000615, further R-band photometry
  20. GRB 000615: NIR observations
  21. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  22. GRB000615, R-band photometry
  23. GRB000615: BeppoSAX refined coordinates
  24. GRB980425, HST/STIS observations of the host galaxy
  25. GRB000615: BeppoSAX GRB Alert
  26. The Hosts of GRB 980703 and GRB 971214
  27. GRB 000301C: Further Late-Time HST/STIS observations
  28. GRB000528: follow-up X-ray measurements and update of IPN annulus
  29. Optical Follow-up of GRB000529 Error Box
  30. GRB980519, HST/STIS observations of the host galaxy
  31. GRB000607, Radio Observations
  32. BeppoSAX X-ray transient/possible GRB000608
  33. GRB000604 optical non-detection
  34. GRB000604 - Optical observations
  35. GRB000607, A SHORT, HARD BURST
  36. GRB000604, optical observations
  37. GRB000528, optical observations at ESO
  38. GRB 000604 optical observations
  39. GRB 000418: Detection of the Host Galaxy
  40. GRB000604, optical observations, comparison with DPOSS
  41. GRB000604 [IPN Position]
  42. GRB000528, Radio Observations
  43. X-ray Afterglow of GRB 000529
  44. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  45. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  46. GRB000529: Optical Observations
  47. IPN localization and time history of GRB000528
  48. New IPN localization of GRB000529
  49. GRB000519: Optical observations
  50. IPN localization of GRB000529
  51. GRB 000528 - WFC measurements
  52. GRB000529: BeppoSAX WFC position
  53. GRB000528: BeppoSAX GRBM observations
  54. GRB 000528 Optical Observations
  55. GRB000519, BVRI field photometry
  56. IPN triangulation of GRB000519
  57. IPN triangulation of GRB000516
  58. Re: GRB000508B : Optical observations
  59. GRB 000418, Optical observation
  60. GRB000508B, optical photometry
  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. GRB 000418, optical observation
  77. GRB000424 Optical Observations
  78. GRB 000418, Optical Observation
  79. GRB000424, optical observations
  80. GRB000424, optical observations
  81. GRB 000424, Optical Observations
  82. GRB 000418, Optical Observation
  83. GRB000418, near-infrared observations
  84. BeppoSAX GRB000424
  85. Correction to IPN error box for GRB000419
  86. IPN error box for GRB000418
  87. GRB000419 [IPN Position]
  88. GRB000416 Optical Observations
  89. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  90. GRB000416 BRJK observations
  91. 1SAXJ1715.0-7134 refined position
  92. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  93. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  94. Budget cuts in BeppoSAX operations: impact on GRB observations
  95. GRB 000408, optical observations
  96. Refined IPN error box for GRB000408
  97. GRB 991208, UBVRI field photometry
  98. GRB000301c results
  99. GRB000408: Optical CCD Observations from MIRO
  100. GRB000408, lotis optical observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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