Skip to main content
New! BOOM Notices and Schema v7.0.0. 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 071028: SARA observations of variable source
  2. Swift UVOT upper limits to GRB071028
  3. GRB071028: Xinglong EST V-band upper limit
  4. GRB 071028: Swift-XRT Team refined analysis
  5. GRB 071028, Swift-BAT refined analysis
  6. GRB 071028: Swift detection of a burst
  7. GRB 071025: Kuiper Telescope Optical Observations
  8. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  9. GRB 071018: Revised BAT position
  10. GRB 071025A: RAPTOR Observations of Complex Early Optical Behavior
  11. GRB071021: MARGE Optical Limits
  12. GRB071020, optical upper limit
  13. GRB 071025: SARA VRI upper limits
  14. GRB 071025 Milagro GeV/TeV Observations
  15. GRB 071025: SQIID JHK photometry
  16. GRB 071025A: Complex Early-Time IR Behavior, Simultaneous with Gamma- and X-rays
  17. GRB071025: Optical Pre-imaging from Palomar
  18. Swift UVOT upper limits
  19. GRB071025: Xinglong TNT I-band upper limit
  20. GRB 071025: Swift-XRT Team refined analysis
  21. GRB 060602A: host redshift
  22. GRB 071025, Swift-BAT refined analysis
  23. GRB 071025: Early Super-LOTIS Observations
  24. GRB 071025: R/I-band update
  25. GRB071021 : CFHT Ks-band observation
  26. GRB 071025: ROTSE-III Refined Analysis
  27. GRB 071025: I-detection, R-dropout?
  28. GRB 071025: Swift XRT refined position
  29. GRB 071025a: PAIRITEL observations
  30. GRB071025: REM NIR afterglow
  31. GRB 071025: ROTSE-III Detection of Optical Counterpart
  32. GRB 071025: Swift detection of a burst
  33. GRB 071021: R-band detection and analysis
  34. GRB 071020: BTA spectroscopy
  35. GRB071021: Optical+NIR observations
  36. Possible radio detection of GRB 071021 with the VLA
  37. Optical observations of GRB 071020
  38. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  39. GRB 071020: SARA observations
  40. Radio detection of GRB 071020 with the VLA
  41. GRB071010b: optical observation
  42. GRB 071021: Subaru NIR observation
  43. GRB071021: MITSuME Okayama Optical Upper Limits
  44. GRB 071021: Magellan i-band observation
  45. GRB 071021: Magellan R-band observation
  46. GRB 071021: Z-band detection
  47. GRB 071021: correction to GCNC 6968
  48. GRB 071020: Fading slowly?
  49. GRB 071010B: Fading quickly
  50. GRB 071021: optical and NIR observations
  51. GRB 071021: possible high-z burst
  52. GRB 071021, Swift-BAT refined analysis
  53. GRB071018: 2nd epoch obsevations of Xinglong TNT
  54. GRB 071021: retraction of Faulkes Telescope South candidate
  55. GRB 071021: Swift-XRT Team refined analysis
  56. GRB 071021: Xinglong TNT optical Upper Limit
  57. GRB 071021 : Lulin R-band limit
  58. Konus-Wind observation of GRB 071020
  59. GRB 071021: Faulkes Telescope South optical candidate
  60. GRB 071021: Swift detection of a burst
  61. GRB 071010B: Independent Confirmation of Break
  62. GRB071020A: Xinglong TNT Optical afterglow observations
  63. GRB 071020: Swift-XRT refined analysis
  64. GRB 071020, Swift-BAT refined analysis
  65. GRB 071020A: IR Imaging with PAIRITEL
  66. GRB 071020: VLT spectroscopy
  67. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  68. GRB071020 - SDSS Pre-burst Observations
  69. GRB 071020: Swift detection of a bright burst
  70. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  71. GRB 071018: Mercator Telescope optical observations
  72. Swift autonomous slewing re-enabled
  73. GRB071010b: optical observations
  74. GRB 071018: SARA observations
  75. GRB 071018: Swift-XRT observation
  76. GRB 071017 - Swift XRT observations
  77. VLA radio observation of GRB 071018
  78. GRB071018: Correction to the GCN 6936
  79. GRB071018: Correction to the GCN 6936
  80. GRB071018: Correction to the GCN 6936
  81. GRB071018: Correction to the title of the GCN 6936
  82. GRB 071018: Possible OT from Xinglong TNT observation
  83. GRB 071010B: Light Curve Break Confirmed
  84. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  85. GRB 071018, Swift-BAT refined analysis
  86. GRB 071018?: Swift detection of a possible burst
  87. GRB 071010B: Suzaku WAM observation of the prompt emission
  88. GRB 071013: 3rd TLS Epoch - constraints on variability
  89. GRB 071013: TNT optical data refined analysis
  90. GRB 071010B: Keck/DEIMOS emission-line redshift
  91. GRB 071017: a SHORT GRB detected by INTEGRAL
  92. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  93. GRB071013: optical observations
  94. GRB 071010B: Optical observations of EST
  95. GRB 071010B: TLS 3rd Epoch - finally a break??
  96. GRB 071011: MITSuME Optical Observations
  97. GRB 070920A: deep optical observations at the NOT
  98. GRB 071010B: Photometry after 1.6 days
  99. GRB 071010B: Keck/LRIS Photometry
  100. GRB 071010B: TLS 2nd Epoch, 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