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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"

23630 results found.

  1. REVISED LOCATION OF GRB010326A
  2. GRB 980326: Late-time HST/STIS observations
  3. GRB010324, field photometry
  4. GRB010326B, field photometry
  5. GRB010326, field photometry
  6. Further Optical Observations of GRB 010324
  7. GRB010324: BeppoSAX/GRBM data
  8. GRB010324, optical observations
  9. GRB010326B: Localization by HETE (2nd GRB for this date)
  10. GRB010326: Refined Localization by HETE
  11. GRB010326: Localization by HETE
  12. Duration, ECT, peak flux and fluence of GRB010324
  13. GRB010222, late-time optical observation
  14. Support extension to the BeppoSAX mission
  15. GRB010222: Sub-millimeter vanishing act
  16. Sub-millimeter Excess/GRB 010222
  17. GRB 010222
  18. GRB010222 further R-band photometry
  19. GRB 010222: Keck Spectroscopy
  20. GRB010222 further R-band photometry
  21. GRB010222, possible increase of optical decay slope
  22. GRB010220, Optical Observations
  23. GRB010222 R-BAND OBSERVATION
  24. GRB 010222: Near-IR Observations
  25. GRB010222, optical observations
  26. Redshift of the Optical Transient of GRB010222
  27. GRB010214B,Gamma Ray Observations
  28. GRB 010220, simultaneous optical observations
  29. GRB010220: BeppoSAX WFC and GRBM preliminary data
  30. GRB010214: BeppoSAX WFC and GRBM preliminary data
  31. GRB 010214: X-Ray afterglow
  32. J-Band Observation of GRB 010214.
  33. GRB010214, optical observations
  34. GRB010213, optical observations
  35. Possible InfraRed Transient of GRB 010214.
  36. GRB010214 Optical Observation
  37. GRB010213 detected by HETE
  38. IPN Status Report
  39. HETE Status
  40. GRB010126 opt. obs.
  41. GRB010126: CONCAM crude optical limits during GRB
  42. GRB010126, TNG R-band observations
  43. GRB010126 optical observations
  44. GRB010126: Optical observations
  45. IPN/RXTE TRIANGULATION OF GRB010126
  46. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  47. GRB 001212 Optical Observation
  48. GRB 001212 Optical Observation
  49. GRB 001212 optical observation
  50. GRB 001212 possible OA
  51. Confirmation of IPN position for GRB001204
  52. GRB 001105, R-band observation
  53. GRB 001025B, Optical obervations
  54. GRB 991208: HST Imaging of the Host Galaxy
  55. ASM Localization of GRB 001025
  56. GRB001018, Gamma Ray Observations
  57. V,R,I band observations of GRB000926
  58. HETE positions added to GCN
  59. GRB000926 - Amateur Optical Observations
  60. CONCAM null result on GRB001005
  61. GRB 000926 : the host galaxy
  62. GRB 000926 Chandra Observation
  63. Public availability of BeppoSAX data of GRB000926
  64. GRB000926 - Optical observations
  65. GRB000926 - Optical observations
  66. GRB000911: VLT infrared observation
  67. GRB000911: optical VLT observations
  68. GRB000926 K'-band Observation
  69. J and K band observations of GRB 000926
  70. IPN triangulation of GRB000911
  71. False GRB alarm from RXTE/ASM on 8 Sept 2000
  72. GRB000830: Optical observations
  73. GRB000830, TNG B-band observations
  74. IPN localization of GRB000820
  75. GRB000812, TNG R-band observations
  76. GRB000730, Gamma Ray Observations
  77. IPN localization of GRB000812
  78. IPN localization of GRB000811
  79. GRB000801, Gamma Ray Observations
  80. IPN localization of GRB000801
  81. IPN localization of GRB000801
  82. IPN localization of GRB000730B
  83. IPN localization of GRB000730B
  84. IPN localization of GRB000730
  85. GRB 990510: Possible detection of a host galaxy
  86. GRB 990510 Host Galaxy Discovery
  87. IPN localization of GRB000727
  88. GRB 990712: Late time HST/STIS Observations
  89. GRB 991216, HST/STIS observations
  90. GRB 000630: Detection of the Optical Afterglow
  91. GRB000630, Optical Observations
  92. GRB000630, optical observations
  93. GRB000418, HST/STIS Observations
  94. GRB990123: Late-time HST/STIS observations of the host
  95. GRB 990506, HST/STIS Observations of the Host Galaxy
  96. GRB000623
  97. GRB 000620: J-band observations
  98. GRB000620, optical observations
  99. GRB000607, optical observations
  100. GRB 990123: Late-time HST/STIS 50CCD observations of the host

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