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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"

3992 results found.

  1. IPN Triangulation of GRB 150127A
  2. IPN triangulation of GRB 150118C (short/hard)
  3. IPN Triangulation of GRB 141215A (long/intense)
  4. IPN Triangulation of GRB 141202A (short/hard)
  5. GRB 141121A: three epochs of SAO RAS optical observations
  6. IPN Triangulation of GRB 140901A (short/hard/very intense)
  7. IPN triangulation of GRB 140801A (Fermi trigger 428612396)
  8. GRB 140610A: Swift detection of a burst
  9. IPN Triangulation of GRB 131209A
  10. IPN Triangulation of GRB 131126A (short/hard)
  11. IPN Triangulation of GRB 131125A (short/hard)
  12. GRB 131108A: AGILE/GRID observation
  13. Swift Operations in the event of a US Government shutdown
  14. US Government shutdown may impact GRB operation of GCN
  15. GRB 130822A: nearby galaxy redshifts
  16. IPN Triangulation of long GRB 120916A
  17. Corrections to the Fermi-LAT upper limits for GRB 120807A, 120908A, 120909A, and 120911A
  18. Swift starts a new program to find fainter transients
  19. IPN Triangulation of GRB 120328B (long/intense)
  20. GRB 120316A: Fermi-GBM and Fermi-LAT Observations
  21. IPN Triangulation of GRB 120226A
  22. All GCN Circulars available in a tarfile for data mining
  23. IPN triangulation of GRB110825A (very intense, long-duration)
  24. Fermi-GBM data processing and delivery
  25. GRB 100805A: Xinglong TNT optical observation
  26. Swift-BAT trigger 421695 is likely not astrophysical
  27. IPN triangulation of GRB100324B
  28. GRB 081203B: Naming correction for burst detected in Swift-BAT slew data
  29. Soft Gamma Repeater SGR 0501+4516: GBM Detection of multiple bursts
  30. First GLAST Burst Monitor GRB Circulars
  31. Reactivation of SGR 1627-41
  32. procesure for GRB Circular
  33. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  34. Swift-XRT improved positions, and new redshift limits.
  35. GRB 080121 position was incorrect
  36. Disregard the "GRB 071126" position
  37. Swift autonomous slewing re-enabled
  38. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  39. GRB 071003: Possible rebrightening
  40. Update on Swift Status
  41. Swift Status and XRT Calibration Uncertainties
  42. GCN Swift XRT update position notices and enhanced position circulars
  43. Keck Laser Guide Star Adaptive Optics Imaging of GRB 070621
  44. GRB 070125: Break in Optical Decay
  45. GRB 060929: Further XRT Refined Analysis
  46. test of new software, grb
  47. GRB 060927: Early color
  48. GRB 060526: Break in X-ray light curve
  49. GRB 051221: Improved astrometry of the IR counterpart
  50. GRB051105: optical observations
  51. GRB 051105a: MDM Observations
  52. Swift-BAT trigger 147918 is not a real GRB
  53. GRB 050721A: Swift-BAT refined analysis
  54. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  55. Retraction of three Swift GRB triggers
  56. GRB 050319: ROTSE-III Refined Analysis
  57. SGR 1806-20: Low frequency GMRT results; submission to GCN circulars
  58. GRB041006: MASTER optical observations
  59. IBAS GRB Alerts 1978-1980
  60. IPN Summary of SGR1806-20 Activity in 2004
  61. GRB and XRF on April 27, 2004. Detection by Konus-Wind and Helicon (Coronas-F)
  62. On Line Availability of Archival HETE Fregate Data and Lightcurves
  63. GRB 040223 XMM-Newton observation ...
  64. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  65. XRF030723 (=H2777): Second Epoch Magellan Observations
  66. GRBlog: Compilation of all GCN Circ. data
  67. GRB 030329 and SN 2003dh
  68. GRB030329: multiple re-brightening phases
  69. GRB: Non-Referencing of GCN Circulars.
  70. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  71. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  72. Distribution of INTEGRAL SPI-ACS triggers
  73. GRB021016(=H2397): A Long GRB Localized by HETE
  74. GRB 021004: Optical observations, AUDE network
  75. IPN GCN Circulars now to be issued without restriction
  76. GRB/XRF 020427, detection of an underlying system with the VLT
  77. HETE Fully-Automated GCN Notices
  78. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  79. HETE Status
  80. HETE positions added to GCN
  81. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  82. GRB000301c results
  83. Optical observations of GRB000301c
  84. GCN resumes full operations
  85. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  86. BeppoSAX: A new fast X-ray transient
  87. GRB 990506, Optical Observations
  88. GRB 990123: near-infrared observations.
  89. GRB981226, BeppoSAX Christmas GRB
  90. GRB980515, BeppoSAX IAUC to be submitted
  91. IPN web site of GRBs
  92. GRB980329, Fading IR counterpart to radio source

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