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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"

17643 results found.

  1. GRB000926 - Optical observations
  2. GRB 000926, Optical Observations
  3. GRB000926 K'-band Observation
  4. J and K band observations of GRB 000926
  5. CONCAM crude optical limits before and after GRB000926
  6. GRB 000926: Optical candidate
  7. Optical candidate for GRB000926
  8. GRB 000911, BVRI field photometry
  9. GRB000911, Radio and Optical observations
  10. GRB000911: Optical observations
  11. False GRB alarm from RXTE/ASM on 8 Sept 2000
  12. GRB000830, BVRI field photometry
  13. GRB000830: Optical observations
  14. IPN localization of GRB000820
  15. IPN localization of GRB000812
  16. GRB000801, VLT-Antu R-band observations
  17. GRB 991208 Host Galaxy Imaging
  18. IPN localization of GRB000730B
  19. IPN localization of GRB000730B
  20. GRB 990510: Possible detection of a host galaxy
  21. GRB 990510 Host Galaxy Discovery
  22. GRB 990712: Late time HST/STIS Observations
  23. GRB 991216, HST/STIS observations
  24. GRB000630, optical observations
  25. GRB000630, Revised BVRI Field Photometry
  26. GRB000630, Optical Observations
  27. GRB000630, optical observations
  28. GRB000630, optical observations
  29. GRB000630, BVRI Field Photometry
  30. GRB000630, optical observations
  31. GRB000630, optical observations
  32. GRB000630: Optical observations
  33. possible optical counterpart of GRB 000630
  34. IPN triangulation of GRB000630
  35. GRB 000620, optical observations
  36. GRB000418, HST/STIS Observations
  37. GRB990123: Late-time HST/STIS observations of the host
  38. GRB000620, optical observations
  39. GRB000620 - Optical observations
  40. GRB000620 Optical observations
  41. GRB000620: BeppoSAX WFC and GRBM detection
  42. GRB000607, optical observations
  43. GRB 000615: NIR further observations
  44. GRB000616 optical observations
  45. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  46. GRB000615, further R-band photometry
  47. GRB 000615: NIR observations
  48. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  49. GRB000615, R-band photometry
  50. GRB 000301C: Further Late-Time HST/STIS observations
  51. GRB000528: follow-up X-ray measurements and update of IPN annulus
  52. BeppoSAX X-ray transient/possible GRB000608
  53. GRB000604 - Optical observations
  54. GRB000607, A SHORT, HARD BURST
  55. GRB000604, optical observations
  56. GRB000528, optical observations at ESO
  57. GRB 000418: Detection of the Host Galaxy
  58. GRB000604, optical observations, comparison with DPOSS
  59. GRB000528, Radio Observations
  60. X-ray Afterglow of GRB 000529
  61. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  62. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  63. GRB 000528 - WFC measurements
  64. GRB000519, BVRI field photometry
  65. GRB000508B, optical photometry
  66. GRB000508B, BVR field photometry
  67. Possible GRB-related phenomenon
  68. RXTE/ASM and IPN localization of GRB 000508B
  69. GRB000424, UBVRI field photometry
  70. GRB000418, UBVRI field photometry update
  71. GRB000424, optical observations
  72. GRB 000429, optical observation
  73. GRB 000429, UBVRI field photometry
  74. GRB 000418, UBVRI field photometry
  75. GRB 000418, optical observation
  76. GRB 000418, Optical Observation
  77. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  78. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  79. Budget cuts in BeppoSAX operations: impact on GRB observations
  80. GRB 000408, optical observations
  81. Refined IPN error box for GRB000408
  82. GRB 991208, UBVRI field photometry
  83. GRB000408, lotis optical observations
  84. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  85. GRB000326 Optical Observations
  86. GRB000301C - Addendum to GCN 623
  87. GRB 000326: Optical Observations
  88. GRB000326, Radio observations
  89. GRB000326 [IPN Position]
  90. GRB000313, Radio observations
  91. GRB 000313 - optical transient in the BATSE error box
  92. GRB 000307, BVRI Field Photometry
  93. GRB 000301C: HST/STIS CCD Imaging of the field
  94. IPN error box for GRB000307
  95. GRB000301C, optical R-band observations
  96. GRB 000301C Optical Observations
  97. GRB 000301C: K' Observations
  98. GRB000301C - Host galaxy not detected in R (?)
  99. Optical observations of GRB000301c
  100. GRB000301C, Radio observations

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