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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"

27478 results found.

  1. GRB 020705: Optical observations
  2. GRB 020625, optical observations
  3. GRB 020625: Optical observations
  4. GRB 020531: optical photometry of Chandra sources
  5. HETE #2081: Optical observations
  6. GRB/XRF 020427, detection of an underlying system with the VLT
  7. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  8. AXP 1E2259+586: quasi-simultaneous optical observation
  9. AXP 1E2259+586 optical observations
  10. GRB 020531, simultaneous optical observations
  11. GRB 020604, optical observations
  12. GRB 020531/Candidate Redshift
  13. GRB020531: Detection of Candidate Host Galaxy
  14. GRB 020418, optical/near-IR observations
  15. GRB020531: Upper Limit for Detection of Two TAROT Sources
  16. GRB 020603: Optical observations
  17. IPN detection of possible bursts from SGR1806-20
  18. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  19. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  20. HST detection of the likely host galaxy of GRB 020124
  21. XRF020427: Chandra Observations and Candidate X-ray Counterparts
  22. GRB(XRF) 020427: X-ray afterglow with BeppoSAX
  23. GRB020321 : Optical observations.
  24. GRB020331: Third Epoch and Revised Second Epoch Optical
  25. The end of BSAX GRB activities
  26. GRB 020418: Optical observations
  27. GRB 020124: Optical observations
  28. GRB 020418: Optical observations
  29. GRB020410: BeppoSAX NFI observations refined analysis
  30. Mars Odyssey joins the IPN
  31. GRB020405: predicted break
  32. GRB 020409: Optical observations
  33. GRB 020409, No Optical Detection to R = 22
  34. GRB 020409: No Evidence for an Optical Afterglow
  35. GRB 020409, 2nd epoch optical observations
  36. GRB 020331 Kyoto observation on March 31
  37. GRB 020409
  38. GRB 020409, No Optical Detection to R = 20
  39. GRB020406(?), optical observations
  40. X-ray afterglow of GRB020321
  41. GRB020331: Confirmation of Afterglow Candidate with Magellan
  42. ASM GRB candidate 020406 refined error box
  43. GRB 020405: Moderate-resolution spectroscopy
  44. GRB020331: Optical Observations of Afterglow Candidate
  45. GRB020406(?), optical observations
  46. Revised Photometry of the Optical Afterglow of GRB 020405
  47. GRB 020331: Candidate Optical Afterglow
  48. GRB 020405: Decay index
  49. GRB020405, Radio Observations
  50. GRB020405: VLT spectroscopy
  51. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  52. GRB 020405, U-band observations
  53. GRB 020405: Optical afterglow candidate
  54. GRB011212: Optical Observations
  55. GRB 020331: NIR Observations
  56. GRB 020331: NIR Observations
  57. GRB020331 NIR observation at KPNO (re-submission)
  58. GRB02033 NIR observation at KPNO
  59. GRB020331 field photometry
  60. GRB 020331, NIR observations
  61. GRB 020331: Optical observations
  62. GRB 020322: BeppoSAX observations of the X-ray afterglow
  63. GRB011211: HST Observations of Optical Afterglow and Host Galaxy
  64. GRB 020322, Radio observations
  65. Near-Infrared Observations of GRB020322 at TIRGO
  66. GRB 020321, Radio Observations
  67. GRB 020322: Optical Observations
  68. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  69. GRB 020321: Optical observations
  70. GRB020317 BVRI field photometry
  71. GRB 020322 optical observations
  72. GRB020322: Candidate Optical Afterglow
  73. GRB 020322 optical observation
  74. GRB020322, optical observations
  75. GRB 020322: Optical candidate
  76. GRB 020321: Optical observations
  77. GRB 011121: Fourth Epoch of HST Imaging
  78. GRB020321: BeppoSAX/NFI Observations
  79. GRB020321: a faint BeppoSAX detection
  80. GRB020305: NIR observations
  81. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  82. GRB 020305: Optical Observations
  83. GRB020317, optical observations
  84. GRB 020317: Optical observations
  85. GRB 011121: Third HST Epoch
  86. GRB020305: Properties of the Candidate Optical Afterglow
  87. GRB 011121: HST Observations reveal an intermediate-time multicolor
  88. GRB011121, possible supernova association
  89. GRB020305: Subaru Optical Observations
  90. GRB 020305: Optical observations
  91. XRF/GRB 011030: Detection of the Probable Host Galaxy
  92. GRB 020305: Candidate optical afterglow
  93. GRB020305 (=H1939): Localization of a GRB by HETE
  94. HST Imaging of the afterglow and host of GRB 011121
  95. GRB 010921: HST Observations
  96. IPN detection and localization of Cygnus X-1 flares
  97. GRB020127: Further VLA Observations of Possible Counterparts
  98. IPN detection of further SGR1900+14 activity
  99. IPN/HETE Detection of Bursts from SGR1900+14
  100. GRB020127: Palomar and VLA Observations of Possible Counterparts

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