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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"

35992 results found.

  1. GRB000630, optical observations
  2. GRB000630, BVRI Field Photometry
  3. GRB000630, optical observations
  4. GRB000630: Optical observations
  5. possible optical counterpart of GRB 000630
  6. IPN triangulation of GRB000630
  7. GRB 000623, optical observations
  8. GRB 000620, optical observations
  9. GRB000418, HST/STIS Observations
  10. GRB990123: Late-time HST/STIS observations of the host
  11. GRB 990506, HST/STIS Observations of the Host Galaxy
  12. GRB000623
  13. GRB 000620: J-band observations
  14. GRB990308, HST/STIS observations of the host galaxy
  15. IPN annulus for GRB000620
  16. GRB000615, Radio observations
  17. GRB000607, optical observations
  18. GRB 000615: NIR further observations
  19. BeppoSAX ALERT: GRB000620
  20. GRB000620: BeppoSAX Alert
  21. GRB990123, HST/STIS observations of the host galaxy
  22. GRB 000615, near-infrared observations
  23. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  24. GRB000616 [IPN Position]
  25. GRB000615B [IPN Position]
  26. GRB000615, further R-band photometry
  27. GRB 000615: NIR observations
  28. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  29. GRB000615, R-band photometry
  30. GRB980425, HST/STIS observations of the host galaxy
  31. GRB000615: BeppoSAX GRB Alert
  32. The Hosts of GRB 980703 and GRB 971214
  33. GRB 000301C: Further Late-Time HST/STIS observations
  34. GRB000528: follow-up X-ray measurements and update of IPN annulus
  35. GRB980519, HST/STIS observations of the host galaxy
  36. GRB000607, Radio Observations
  37. GRB000604 - Optical observations
  38. GRB000607, A SHORT, HARD BURST
  39. GRB000604, optical observations
  40. GRB000528, optical observations at ESO
  41. GRB 000604 optical observations
  42. GRB 000418: Detection of the Host Galaxy
  43. GRB000604, optical observations, comparison with DPOSS
  44. GRB000604 [IPN Position]
  45. X-ray Afterglow of GRB 000529
  46. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  47. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  48. IPN localization and time history of GRB000528
  49. New IPN localization of GRB000529
  50. GRB 000528 - WFC measurements
  51. GRB000528: BeppoSAX GRBM observations
  52. GRB 000528 Optical Observations
  53. GRB000519, BVRI field photometry
  54. IPN triangulation of GRB000519
  55. IPN triangulation of GRB000516
  56. Re: GRB000508B : Optical observations
  57. GRB 000418, Optical observation
  58. GRB000508B, optical photometry
  59. GRB000508B, BVR field photometry
  60. Possible GRB-related phenomenon
  61. RXTE/ASM and IPN localization of GRB 000508B
  62. GRB000424, UBVRI field photometry
  63. GRB 000424 Optical Observations
  64. GRB000418, UBVRI field photometry update
  65. The redshift of GRB 000418
  66. GRB 000429, optical observation
  67. GRB 000429, UBVRI field photometry
  68. IPN localization of GRB000429
  69. GRB 000418, UBVRI field photometry
  70. GRB000418, K'-band photometry
  71. GRB 000418, Optical Observation
  72. GRB 000418, optical observation
  73. GRB000424 Optical Observations
  74. GRB 000418, Optical Observation
  75. GRB 000424, Optical Observations
  76. GRB 000418, Optical Observation
  77. GRB000418, near-infrared observations
  78. Correction to IPN error box for GRB000419
  79. IPN error box for GRB000418
  80. GRB000419 [IPN Position]
  81. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  82. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  83. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  84. Budget cuts in BeppoSAX operations: impact on GRB observations
  85. GRB 000408, optical observations
  86. Refined IPN error box for GRB000408
  87. GRB 991208, UBVRI field photometry
  88. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  89. GRB000408 [IPN Position]
  90. GRB000326 Optical Observations
  91. GRB000301C - Addendum to GCN 623
  92. GRB000301C - R magnitude lower limit
  93. GRB 000323, optical observations
  94. GRB 000326: Optical Observations
  95. GRB000326, Radio observations
  96. GRB000326 [IPN Position]
  97. GRB 000307 optical observations
  98. GRB000323 [IPN Position]
  99. GRB000315 [IPN Positions]
  100. GRB 000313 - optical transient in the BATSE error box

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