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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"

21801 results found.

  1. GRB041006: RTT150 Optical Observations
  2. GRB 041016:Optical limit during first minute
  3. GRB041016: MASTER: Optical observations
  4. GRB 041015: Optical Observations at Rikubetsu
  5. GRB041006: Near Infrared observations
  6. GRB 041015 R band observations
  7. GRB041015: MASTER: Optical observations
  8. GRB041006: Fading X-ray Afterglow Observed with Chandra
  9. GRB 041006 R observations in Loiano
  10. GRB041006: VLT observations of the afterglow and host galaxy
  11. GRB041006: Optical observations and Potential host galaxy
  12. GRB 040924: VLT spectroscopy
  13. GRB 041006: SARA afterglow observations
  14. Search for SN light in XRF 040912 with MEGACAM
  15. GRB 040916: Afterglow Color at Early Times
  16. GRB 041006 Optical afterglow observations
  17. IBAS GRB Alert # 2010
  18. GRB 041006: BR observations with VATT
  19. GRB 041006: Redshift confirmed
  20. GRB041006: Liverpool Telescope optical observations
  21. GRB 041006: Colour measurement
  22. GRB 041006: Radio Observations
  23. GRB041006, further submilllimetre observations
  24. GRB041006: Optical photometry and spectroscopy at TNG
  25. GRB041006 (= H3570): Chandra Observations In Progress
  26. GRB041006, optical I observation
  27. GRB041006 (=HETE3570): optical observations
  28. ROTSE-IIIa Observations of GRB 041006
  29. GRB041006, submillimetre observations
  30. GRB041006: MASTER optical observations
  31. GRB 041006: Optical decay
  32. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  33. XRF 020903: Observations of the Host Galaxy (authors)
  34. XRF 020903: Observations of the Host Galaxy
  35. SGR 1806-20 still active
  36. GRB 040924: Second Epoch WSRT Radio Observations
  37. radio observations, GRB 040924
  38. GRB040929: MASTER optical observations
  39. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  40. GRB040924,optical observation
  41. GRB040924, RTT150 optical observation
  42. GRB 040924: detection of possible host galaxy by Subaru
  43. GRB040924, RTT150 optical observation
  44. GRB040924: KAIT observations
  45. GRB 040924: WSRT Radio Observations
  46. GRB040924 : Optical candidate observations at Lulin observatory
  47. GRB040924 : Optical candidate observations at Lulin observatory
  48. GRB040924: Optical afterglow properties
  49. GRB 040924: RTT150 optical observations
  50. GRB040924: MASTER Optical observations
  51. GRB040924 (H3564): Optical afterglow candidate
  52. XRF 040912: Radio Observations
  53. XRF 040916: Radio Observations
  54. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  55. XRF040916: continuing decay of OT
  56. TAROT Observations of GRB 040916 (HETE #3558)
  57. XRF040916, optical observations
  58. XRF 040912, identification of CXO sources
  59. XRF040916, Ic observations
  60. XRF040916: optical follow-up observations
  61. GRB040916: Archival optical observations
  62. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  63. GRB040916: Optical observations
  64. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  65. GRB040912 (= H3557): Chandra Observations Scheduled
  66. GRB 040912: Optical Observations
  67. GRB/XRF040912,optical observations
  68. GRB 040912, BVRI observations
  69. Optical observations of GRB/XRF 040912 = HETE 3557
  70. Optical observations of field of GRB040912
  71. HETE 3557: Optical observations
  72. GRB040827: analysis of the XMM-Newton observation
  73. GRB 040827 - Radio Observations
  74. GRB040825A: Optical observations
  75. GRB040825A: Optical observations
  76. GRB 040827: optical and NIR observations at the VLT
  77. GRB 040827: 2nd epoch of Magellan K-band imaging
  78. GRB 040827: Possible detection of optical afterglow
  79. GRB 040827: RTT150 optical observations
  80. GRB 040825B: Optical observations
  81. GRB040827 optical observations
  82. GRB 040825A,optical observations
  83. GRB040825A: optical observations
  84. GRB040825B: optical observations
  85. GRB040825B (=H3510): An XRF Localized in Real Time by HETE
  86. GRB 040825A: Optical observations.
  87. GRB040825B: Correction to GCN 2657
  88. GRB 040825: Optical observations
  89. GRB 040812: Second epoch CXO Observations
  90. XRF040812: GMRT observations
  91. XRF 040812: optical observation at VLT
  92. GRB 040812: Optical counterparts of CXO sources
  93. GRB 040812: Keck and LCO optical observations
  94. GRB 040812: Keck and LCO observations
  95. GRB 040812: radio observations
  96. GRB040812, optical/IR observations
  97. GRB 040810: Optical observations of a limited region
  98. XRF040701: Optical Observations at ESO
  99. GRB 040730, infrared observations
  100. GRB 040730: Optical observations

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