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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"

37508 results found.

  1. Updated IPN coordinates for GRB000801
  2. IPN localization of GRB000801
  3. IPN localization of GRB000730B
  4. IPN localization of GRB000730B
  5. IPN localization of GRB000730
  6. GRB 990510: Possible detection of a host galaxy
  7. GRB 990510 Host Galaxy Discovery
  8. GRB 000727, optical observations
  9. IPN localization of GRB000727
  10. GRB 990705, HST/STIS observations of the host galaxy
  11. GRB 990712: Late time HST/STIS Observations
  12. GRB 991216, HST/STIS observations
  13. GRB981226, HST/STIS observations of the host galaxy
  14. GRB 000630: Detection of the Optical Afterglow
  15. GRB000630, Revised BVRI Field Photometry
  16. GRB000630, Optical Observations
  17. GRB000630, optical observations
  18. GRB000630, BVRI Field Photometry
  19. GRB000630, optical observations
  20. GRB000630: Optical observations
  21. possible optical counterpart of GRB 000630
  22. IPN triangulation of GRB000630
  23. GRB 000623, optical observations
  24. GRB 000620, optical observations
  25. GRB000418, HST/STIS Observations
  26. GRB990123: Late-time HST/STIS observations of the host
  27. GRB 990506, HST/STIS Observations of the Host Galaxy
  28. GRB000623
  29. GRB 000620: J-band observations
  30. GRB990308, HST/STIS observations of the host galaxy
  31. IPN annulus for GRB000620
  32. GRB000615, Radio observations
  33. GRB000607, optical observations
  34. GRB 000615: NIR further observations
  35. BeppoSAX ALERT: GRB000620
  36. GRB000620: BeppoSAX Alert
  37. GRB990123, HST/STIS observations of the host galaxy
  38. GRB 000615, near-infrared observations
  39. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  40. GRB000616 [IPN Position]
  41. GRB000615B [IPN Position]
  42. GRB000615, further R-band photometry
  43. GRB 000615: NIR observations
  44. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  45. GRB000615, R-band photometry
  46. GRB980425, HST/STIS observations of the host galaxy
  47. GRB000615: BeppoSAX GRB Alert
  48. The Hosts of GRB 980703 and GRB 971214
  49. GRB 000301C: Further Late-Time HST/STIS observations
  50. GRB000528: follow-up X-ray measurements and update of IPN annulus
  51. GRB980519, HST/STIS observations of the host galaxy
  52. GRB000607, Radio Observations
  53. GRB000604 - Optical observations
  54. GRB000607, A SHORT, HARD BURST
  55. GRB000604, optical observations
  56. GRB000528, optical observations at ESO
  57. GRB 000604 optical observations
  58. GRB 000418: Detection of the Host Galaxy
  59. GRB000604, optical observations, comparison with DPOSS
  60. GRB000604 [IPN Position]
  61. X-ray Afterglow of GRB 000529
  62. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  63. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  64. IPN localization and time history of GRB000528
  65. New IPN localization of GRB000529
  66. GRB 000528 - WFC measurements
  67. GRB000528: BeppoSAX GRBM observations
  68. GRB 000528 Optical Observations
  69. GRB000519, BVRI field photometry
  70. IPN triangulation of GRB000519
  71. IPN triangulation of GRB000516
  72. Re: GRB000508B : Optical observations
  73. GRB 000418, Optical observation
  74. GRB000508B, optical photometry
  75. GRB000508B, BVR field photometry
  76. Possible GRB-related phenomenon
  77. RXTE/ASM and IPN localization of GRB 000508B
  78. GRB000424, UBVRI field photometry
  79. GRB 000424 Optical Observations
  80. GRB000418, UBVRI field photometry update
  81. The redshift of GRB 000418
  82. GRB 000429, optical observation
  83. GRB 000429, UBVRI field photometry
  84. IPN localization of GRB000429
  85. GRB 000418, UBVRI field photometry
  86. GRB000418, K'-band photometry
  87. GRB 000418, Optical Observation
  88. GRB 000418, optical observation
  89. GRB000424 Optical Observations
  90. GRB 000418, Optical Observation
  91. GRB 000424, Optical Observations
  92. GRB 000418, Optical Observation
  93. GRB000418, near-infrared observations
  94. Correction to IPN error box for GRB000419
  95. IPN error box for GRB000418
  96. GRB000419 [IPN Position]
  97. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  98. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  99. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  100. Budget cuts in BeppoSAX operations: impact on GRB observations

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