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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"

35277 results found.

  1. GRB000615, Radio observations
  2. GRB000607, optical observations
  3. GRB 000615: NIR further observations
  4. BeppoSAX ALERT: GRB000620
  5. GRB000620: BeppoSAX Alert
  6. GRB990123, HST/STIS observations of the host galaxy
  7. GRB 000615, near-infrared observations
  8. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  9. GRB000616 [IPN Position]
  10. GRB000615B [IPN Position]
  11. GRB000615, further R-band photometry
  12. GRB 000615: NIR observations
  13. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  14. GRB000615, R-band photometry
  15. GRB980425, HST/STIS observations of the host galaxy
  16. GRB000615: BeppoSAX GRB Alert
  17. The Hosts of GRB 980703 and GRB 971214
  18. GRB 000301C: Further Late-Time HST/STIS observations
  19. GRB000528: follow-up X-ray measurements and update of IPN annulus
  20. GRB980519, HST/STIS observations of the host galaxy
  21. GRB000607, Radio Observations
  22. GRB000604 - Optical observations
  23. GRB000607, A SHORT, HARD BURST
  24. GRB000604, optical observations
  25. GRB000528, optical observations at ESO
  26. GRB 000604 optical observations
  27. GRB 000418: Detection of the Host Galaxy
  28. GRB000604, optical observations, comparison with DPOSS
  29. GRB000604 [IPN Position]
  30. X-ray Afterglow of GRB 000529
  31. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  32. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  33. IPN localization and time history of GRB000528
  34. New IPN localization of GRB000529
  35. GRB 000528 - WFC measurements
  36. GRB000528: BeppoSAX GRBM observations
  37. GRB 000528 Optical Observations
  38. GRB000519, BVRI field photometry
  39. IPN triangulation of GRB000519
  40. IPN triangulation of GRB000516
  41. Re: GRB000508B : Optical observations
  42. GRB 000418, Optical observation
  43. GRB000508B, optical photometry
  44. GRB000508B, BVR field photometry
  45. Possible GRB-related phenomenon
  46. RXTE/ASM and IPN localization of GRB 000508B
  47. GRB000424, UBVRI field photometry
  48. GRB 000424 Optical Observations
  49. GRB000418, UBVRI field photometry update
  50. The redshift of GRB 000418
  51. GRB 000429, optical observation
  52. GRB 000429, UBVRI field photometry
  53. IPN localization of GRB000429
  54. GRB 000418, UBVRI field photometry
  55. GRB000418, K'-band photometry
  56. GRB 000418, Optical Observation
  57. GRB 000418, optical observation
  58. GRB000424 Optical Observations
  59. GRB 000418, Optical Observation
  60. GRB 000424, Optical Observations
  61. GRB 000418, Optical Observation
  62. GRB000418, near-infrared observations
  63. Correction to IPN error box for GRB000419
  64. IPN error box for GRB000418
  65. GRB000419 [IPN Position]
  66. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  67. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  68. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  69. Budget cuts in BeppoSAX operations: impact on GRB observations
  70. GRB 000408, optical observations
  71. Refined IPN error box for GRB000408
  72. GRB 991208, UBVRI field photometry
  73. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  74. GRB000408 [IPN Position]
  75. GRB000326 Optical Observations
  76. GRB000301C - Addendum to GCN 623
  77. GRB000301C - R magnitude lower limit
  78. GRB 000323, optical observations
  79. GRB 000326: Optical Observations
  80. GRB000326, Radio observations
  81. GRB000326 [IPN Position]
  82. GRB 000307 optical observations
  83. GRB000323 [IPN Position]
  84. GRB000315 [IPN Positions]
  85. GRB 000313 - optical transient in the BATSE error box
  86. GRB000301C - B and R photometry
  87. GRB000301C - R photometry
  88. GRB 000307, Optical Observations
  89. GRB 000307, BVRI Field Photometry
  90. GRB 000301C: Optical Spectrum and Redshift
  91. GRB 000301C: Optical Spectrum and Redshift
  92. GRB 000301C: A Precise Redshift Determination
  93. GRB 000301C, Optical Observation
  94. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  95. GRB 000301C: HST/STIS CCD Imaging of the field
  96. IPN error box for GRB000307
  97. GRB 000301c: K' observations
  98. GRB000301C, optical R-band observations
  99. GRB000301c - R photometry and nearby faint source confirmation
  100. GRB 000301C, Optical Observation

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