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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"

42589 results found.

  1. GRB000615: H-band observations
  2. GRB990308, HST/STIS observations of the host galaxy
  3. GRB000620 Optical observations
  4. IPN annulus for GRB000620
  5. GRB000620: BeppoSAX WFC and GRBM detection
  6. GRB000615, Radio observations
  7. GRB000607, optical observations
  8. GRB 000615: NIR further observations
  9. GRB000620: refined BeppoSAX/WFC coordinates
  10. BeppoSAX ALERT: GRB000620
  11. GRB000620: BeppoSAX Alert
  12. GRB990123, HST/STIS observations of the host galaxy
  13. GRB000616 optical observations
  14. GRB 000615, near-infrared observations
  15. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  16. GRB000615, further R-band photometry
  17. GRB 000615: NIR observations
  18. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  19. GRB000615: BeppoSAX refined coordinates
  20. GRB980425, HST/STIS observations of the host galaxy
  21. GRB000615: BeppoSAX GRB Alert
  22. The Hosts of GRB 980703 and GRB 971214
  23. GRB 000301C: Further Late-Time HST/STIS observations
  24. GRB000528: follow-up X-ray measurements and update of IPN annulus
  25. Optical Follow-up of GRB000529 Error Box
  26. GRB980519, HST/STIS observations of the host galaxy
  27. GRB000607, Radio Observations
  28. BeppoSAX X-ray transient/possible GRB000608
  29. GRB000604 optical non-detection
  30. GRB000604 - Optical observations
  31. GRB000607, A SHORT, HARD BURST
  32. GRB000604, optical observations
  33. GRB000528, optical observations at ESO
  34. GRB 000604 optical observations
  35. GRB 000418: Detection of the Host Galaxy
  36. GRB000604, optical observations, comparison with DPOSS
  37. GRB000604 [IPN Position]
  38. GRB000528, Radio Observations
  39. X-ray Afterglow of GRB 000529
  40. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  41. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  42. GRB000529: Optical Observations
  43. IPN localization and time history of GRB000528
  44. New IPN localization of GRB000529
  45. GRB000519: Optical observations
  46. GRB000529: BeppoSAX WFC position
  47. GRB000528: BeppoSAX GRBM observations
  48. GRB 000528 Optical Observations
  49. GRB000519, BVRI field photometry
  50. IPN triangulation of GRB000519
  51. IPN triangulation of GRB000516
  52. Re: GRB000508B : Optical observations
  53. GRB 000418, Optical observation
  54. GRB000508B, optical photometry
  55. GRB000508B, BVR field photometry
  56. Possible GRB-related phenomenon
  57. RXTE/ASM and IPN localization of GRB 000508B
  58. GRB000424, UBVRI field photometry
  59. GRB 000424 Optical Observations
  60. GRB000418, UBVRI field photometry update
  61. The redshift of GRB 000418
  62. GRB000424, optical observations
  63. GRB 000429, optical observation
  64. GRB 000429, UBVRI field photometry
  65. IPN localization of GRB000429
  66. GRB 000418, UBVRI field photometry
  67. GRB000418, Radio detection
  68. GRB000418, K'-band photometry
  69. GRB 000418, Optical Observation
  70. GRB 000418, optical observation
  71. GRB000424 Optical Observations
  72. GRB 000418, Optical Observation
  73. GRB000424, optical observations
  74. GRB 000424, Optical Observations
  75. GRB 000418, Optical Observation
  76. GRB000418, near-infrared observations
  77. BeppoSAX GRB000424
  78. Correction to IPN error box for GRB000419
  79. IPN error box for GRB000418
  80. GRB000419 [IPN Position]
  81. GRB000416 Optical Observations
  82. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  83. GRB000416 BRJK observations
  84. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  85. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  86. Budget cuts in BeppoSAX operations: impact on GRB observations
  87. GRB 000408, optical observations
  88. Refined IPN error box for GRB000408
  89. GRB 991208, UBVRI field photometry
  90. GRB000301c results
  91. GRB000408: Optical CCD Observations from MIRO
  92. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  93. GRB000408 [IPN Position]
  94. GRB000326 Optical Observations
  95. GRB000301C - Addendum to GCN 623
  96. GRB000301C - R magnitude lower limit
  97. GRB000326, Further VLA observations
  98. GRB 000323, optical observations
  99. GRB 000326: Optical Observations
  100. GRB000326, Radio observations

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