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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"

31730 results found.

  1. GRB000630, optical observations
  2. GRB000630, optical observations
  3. GRB000630: Optical observations
  4. GRB000630, Radio Observations
  5. possible optical counterpart of GRB 000630
  6. GRB 000623, optical observations
  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. GRB 000620: J-band observations
  12. GRB000620, optical observations
  13. GRB000615: H-band observations
  14. GRB990308, HST/STIS observations of the host galaxy
  15. GRB000620 - Optical observations
  16. GRB000620 Optical observations
  17. IPN annulus for GRB000620
  18. GRB000615, Radio observations
  19. GRB000607, optical observations
  20. GRB 000615: NIR further observations
  21. GRB990123, HST/STIS observations of the host galaxy
  22. GRB000616 optical observations
  23. GRB 000615, near-infrared observations
  24. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  25. GRB000615, further R-band photometry
  26. GRB 000615: NIR observations
  27. GRB000615, R-band photometry
  28. GRB980425, HST/STIS observations of the host galaxy
  29. The Hosts of GRB 980703 and GRB 971214
  30. GRB 000301C: Further Late-Time HST/STIS observations
  31. GRB000528: follow-up X-ray measurements and update of IPN annulus
  32. Optical Follow-up of GRB000529 Error Box
  33. GRB000607, Radio Observations
  34. GRB000604 optical non-detection
  35. GRB000604 - Optical observations
  36. GRB000604, optical observations
  37. GRB000528, optical observations at ESO
  38. GRB 000604 optical observations
  39. GRB 000418: Detection of the Host Galaxy
  40. GRB000604, optical observations, comparison with DPOSS
  41. GRB000528, Radio Observations
  42. X-ray Afterglow of GRB 000529
  43. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  44. IPN localization and time history of GRB000528
  45. New IPN localization of GRB000529
  46. GRB000519: Optical observations
  47. IPN localization of GRB000529
  48. GRB 000528 - WFC measurements
  49. IPN triangulation of GRB000519
  50. Re: GRB000508B : Optical observations
  51. GRB 000418, Optical observation
  52. GRB000508B, optical photometry
  53. Possible GRB-related phenomenon
  54. GRB 000424 Optical Observations
  55. The redshift of GRB 000418
  56. GRB000424, optical observations
  57. GRB 000429, optical observation
  58. GRB000418, Radio detection
  59. GRB000418, K'-band photometry
  60. GRB 000418, Optical Observation
  61. GRB 000418, optical observation
  62. GRB000424 Optical Observations
  63. GRB 000418, Optical Observation
  64. GRB000424, optical observations
  65. GRB000424, optical observations
  66. GRB 000424, Optical Observations
  67. GRB 000418, Optical Observation
  68. GRB000418, near-infrared observations
  69. BeppoSAX GRB000424
  70. Correction to IPN error box for GRB000419
  71. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  72. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  73. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  74. GRB 000408, optical observations
  75. Refined IPN error box for GRB000408
  76. GRB000301c results
  77. GRB000408: Optical CCD Observations from MIRO
  78. GRB000408, lotis optical observations
  79. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  80. GRB000326 Optical Observations
  81. GRB000301C - Addendum to GCN 623
  82. GRB000326, Further VLA observations
  83. GRB 000323, optical observations
  84. GRB 000326: Optical Observations
  85. GRB000326, Radio observations
  86. GRB 000307 optical observations
  87. Single error box for GRB000315
  88. GRB000313, Radio observations
  89. GRB000301C - B and R photometry
  90. GRB 000307, Optical Observations
  91. GRB 000301C: Optical Spectrum and Redshift
  92. GRB 000301C: Optical Spectrum and Redshift
  93. GRB 000301C: A Precise Redshift Determination
  94. GRB 000301C, Optical Observation
  95. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  96. GRB 000301C: HST/STIS CCD Imaging of the field
  97. GRB000301C, optical R-band observations
  98. GRB000301c - R photometry and nearby faint source confirmation
  99. GRB 000301C, Optical Observation
  100. GRB 000301C Optical Observations

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