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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"

18340 results found.

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

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