Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. See news and announcements

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"
  1. GRB 070328: Suzaku WAM observation of the prompt emission
  2. INTEGRAL ToO Observation of SGR1806-20
  3. UVOT observations of GRB070330
  4. GRB 070330, Swift-BAT refined analysis
  5. GRB 070330, SMARTS optical/IR observations
  6. GRB 070330: TAROT La Silla observatory optical observations
  7. GRB 070330: Swift-XRT refined analysis
  8. GRB 070330 - Watcher Observations
  9. GRB 070330: Swift detection of a burst
  10. GRB 070328: pseudo-z~2.75 from spectral parameters of the prompt
  11. Konus-Wind observation of GRB 070328
  12. GRB 070328: Swift/UVOT Upper Limits
  13. long burst from SGR 1806-20 detected on March 26
  14. GRB 070328: Swift/XRT Refined Analysis
  15. GRB 070328 : Suzaku ToO follow up starts
  16. GRB 070328, Swift-BAT refined analysis
  17. GRB 070328: Swift detection of a burst
  18. GRB070220: optical observations
  19. GRB070208: optical observations
  20. GRB070223: confirmation of nIR and optical afterglow
  21. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  22. GRB 070311, deep optical photometry
  23. Short-Hard GRB 070209: PROMPT Observations
  24. GRB 070318: Gemini + Magellan spectra
  25. GRB 070318: absorption-line redshift
  26. GRB070318: Swift UVOT continuing observations
  27. GRB070318: Swift-XRT refined analysis
  28. GRB 070318: Swift/UVOT Continued Observations
  29. GRB 070318, Swift-BAT refined analysis
  30. IBAS Alert n. 4176: not a GRB
  31. GRB 070318: Swift detection of a burst with an optical afterglow
  32. GRB 070311: Late Central Engine Activity Optical Flare??
  33. GRB 070311: MDM Optical Monitoring
  34. VLA observation of GRB 070311
  35. GRB 070311: Tautenburg sees afterglow fading
  36. IBAS Alert n. 4169: not a GRB
  37. GRB 070311: Optical observation.
  38. GRB 070311: Optical Brightening
  39. GRB 070306: possible emission-line redshift
  40. GRB 070311: SARA upper limit
  41. GRB 070309: variability of the XRT afterglow candidate
  42. GRB 070311: MDM Optical Follow-up
  43. GRB 070311: RAPTOR Detection of Optical Emission
  44. GRB070311: FRAM early follow-up limit
  45. GRB 070311: P60 Observations
  46. GRB 070311: MDM Optical Detection
  47. GRB 070311: Swift/UVOT Upper Limits
  48. GRB 070311: MITSuME Okayama Optical Observation
  49. GRB 070311: Swift-XRT refined analysis
  50. GRB 070311: PAIRITEL confirmation of variability of REM candidate
  51. GRB 070311: REM candidate afterglow
  52. GRB 070311: a long GRB detected by INTEGRAL
  53. GRB060901: Candidate optical afterglow
  54. GRB070309: Swift/XRT possible afterglow detection
  55. GRB 070125: Chandra X-ray Confirmation of Jet Break
  56. GRB 070309: Swift/UVOT Upper Limits
  57. GRB 070306, optical observation
  58. Swift UVOT Finding Charts for GRB 070309
  59. GRB 070309: A long GRB detected by INTEGRAL
  60. GRB 070125: X-ray light curve analysis
  61. VLA observation of GRB 070306
  62. IBAS Alert 4162: Not a GRB
  63. GRB 070306: NOT observations
  64. GRB 070306 Swift/UVOT refined analysis
  65. GRB070306: confirmation of near infrared afterglow
  66. GRB 070306: ART-3 early optical and near infrared constraints
  67. GRB 070306: IR observations and candidate afterglow
  68. GRB 070306, Swift-BAT refined analysis
  69. GRB 070306: XRT Team Refined Analysis
  70. GRB 070306: Optical and IR observations with KANATA
  71. GRB070306 - SDSS Pre-burst Observations
  72. GRB 070306: Swift detection of a burst
  73. GRB 070223: NIR observations at WHT
  74. GRB070227: Swift-XRT refined analysis
  75. GRB 060605 new redshift
  76. GRB 070125, deep late-time optical observation
  77. VLA observation of GRB 070224
  78. GRB 070227: optical observations
  79. GRB 070223: Optical Observations
  80. GRB 070227: optical observations
  81. GRB 070227: Swift/UVOT Upper Limits
  82. GRB 070227: TAROT La Silla observatory optical observations
  83. GRB 070227, Swift-BAT refined analysis
  84. GRB070227: possible X-ray afterglow detection
  85. GRB 070227: Swift detection of a burst in ground analysis
  86. GRB 920925C: optical afterglow candidate
  87. GRB 070224: Optical afterglow confirmation
  88. IBAS Alert n. 4144: not a GRB
  89. GRB 070224: Swift/UVOT Upper Limits
  90. GRB070224: Swift-XRT Astrometrically Corrected Position
  91. VLA observation of GRB 070223
  92. VLA observation of GRB 070220
  93. GRB070224: Magellan Imaging Observations
  94. GRB 070224: WHT K-band imaging
  95. GRB 070224: MDM Observations
  96. GRB070224: Gemini Imaging Observations
  97. GRB 070224: SARA upper limit
  98. GRB070224: Swift-XRT Refined Analysis
  99. GRB 070224: optical afterglow candidate
  100. GRB 070224, Swift-BAT refined analysis

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov