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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"

25841 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 000620, optical observations
  8. GRB000418, HST/STIS Observations
  9. GRB990123: Late-time HST/STIS observations of the host
  10. GRB 990506, HST/STIS Observations of the Host Galaxy
  11. GRB000623
  12. GRB 000620: J-band observations
  13. GRB000620, optical observations
  14. GRB990308, HST/STIS observations of the host galaxy
  15. GRB000620 - Optical observations
  16. GRB000620 Optical observations
  17. GRB000620: BeppoSAX WFC and GRBM detection
  18. GRB000607, optical observations
  19. GRB 000615: NIR further observations
  20. GRB990123, HST/STIS observations of the host galaxy
  21. GRB000616 optical observations
  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. GRB000615: BeppoSAX refined coordinates
  31. GRB980425, HST/STIS observations of the host galaxy
  32. GRB 000301C: Further Late-Time HST/STIS observations
  33. GRB000528: follow-up X-ray measurements and update of IPN annulus
  34. BeppoSAX X-ray transient/possible GRB000608
  35. GRB000604 - Optical observations
  36. GRB000607, A SHORT, HARD BURST
  37. GRB000604, optical observations
  38. GRB000528, optical observations at ESO
  39. GRB 000418: Detection of the Host Galaxy
  40. GRB000604, optical observations, comparison with DPOSS
  41. GRB000604 [IPN Position]
  42. GRB000528, Radio Observations
  43. X-ray Afterglow of GRB 000529
  44. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  45. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  46. GRB 000528 - WFC measurements
  47. GRB000529: BeppoSAX WFC position
  48. GRB000528: BeppoSAX GRBM observations
  49. GRB 000528 Optical Observations
  50. GRB000519, BVRI field photometry
  51. IPN triangulation of GRB000519
  52. IPN triangulation of GRB000516
  53. GRB000508B, optical photometry
  54. GRB000508B, BVR field photometry
  55. Possible GRB-related phenomenon
  56. RXTE/ASM and IPN localization of GRB 000508B
  57. GRB000424, UBVRI field photometry
  58. GRB000418, UBVRI field photometry update
  59. The redshift of GRB 000418
  60. GRB000424, optical observations
  61. GRB 000429, optical observation
  62. GRB 000429, UBVRI field photometry
  63. IPN localization of GRB000429
  64. GRB 000418, UBVRI field photometry
  65. GRB 000418, optical observation
  66. GRB 000418, Optical Observation
  67. BeppoSAX GRB000424
  68. Correction to IPN error box for GRB000419
  69. IPN error box for GRB000418
  70. GRB000419 [IPN Position]
  71. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  72. GRB000416 BRJK observations
  73. 1SAXJ1715.0-7134 refined position
  74. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  75. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  76. Budget cuts in BeppoSAX operations: impact on GRB observations
  77. GRB 000408, optical observations
  78. GRB 991208, UBVRI field photometry
  79. GRB000301c results
  80. GRB000408, lotis optical observations
  81. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  82. GRB000408 [IPN Position]
  83. GRB000301C - Addendum to GCN 623
  84. GRB000326, Further VLA observations
  85. GRB 000326: Optical Observations
  86. GRB000326, Radio observations
  87. GRB000326 [IPN Position]
  88. GRB 000307 optical observations
  89. GRB000323 [IPN Position]
  90. GRB000315 [IPN Positions]
  91. GRB000313, Radio observations
  92. GRB 000313 - optical transient in the BATSE error box
  93. GRB 000307, Optical Observations
  94. GRB 000307, BVRI Field Photometry
  95. GRB 000301C: Optical Spectrum and Redshift
  96. GRB 000301C: Optical Spectrum and Redshift
  97. GRB 000301C: HST/STIS CCD Imaging of the field
  98. IPN error box for GRB000307
  99. GRB000301C, optical R-band observations
  100. GRB 000301C Optical Observations

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