Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

43612 results found.

  1. GRB 050814: Swift detection of a burst
  2. GRB 050813: Magellan detection of a high redshift galaxy cluster
  3. GRB050813: RTT150 optical observations
  4. GRB 050813: I-band observations
  5. GRB050813, SDSS pre-burst observations
  6. GRB 050813: KAIT optical limit
  7. GRB 050813: Swift-BAT refined analysis
  8. GRB 050813: Photometry of object in XRT error circle
  9. GRB050813: SWIFT/UVOT observation
  10. GRB 050813: Swift XRT afterglow localization
  11. RBO GRB 050714A and GRB 050716 observations
  12. GRB 050813: Possible Short Swift-BAT GRB
  13. GRB050813 (Swift 150139): P60 Observations
  14. Swift-BAT trigger 150131 is not a GRB
  15. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  16. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  17. GRB050803: CrAO optical observations, no OT candidate
  18. Detection of an intermediate burst from SGR 1806-20 on August 8
  19. GRB 050730: WSRT Radio Observations
  20. GRB 050803: PROMPT BVRcIc Observations
  21. GRB 050807: ROTSE-III Optical Limits
  22. GRB 050730, optical observation
  23. GRB050805b: CrAO optical limit
  24. GRB050805a : Null detection report
  25. GRB050730, optical observations
  26. GRB050803, optical observations
  27. Swift-BAT trigger 149118 is very likely not a GRB
  28. Retraction of Swift Trigger 149131 (GRB 050805B)
  29. GRB 050805b: OHP optical limits
  30. GRB 050805b: TAROT optical limits
  31. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  32. Swift-BAT trigger 149118 is probably not a GRB
  33. GRB050802: TNG optical observations
  34. GRB050803: Radio Observation
  35. GRB 050803: RTT150 optical observations
  36. GRB050801: Radio Observation
  37. GRB050730: Radio Detection
  38. GRB050803: CrAO optical observations, possible OT candidate
  39. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  40. GRB 050803: Keck Observations
  41. GRB 050803: Swift-BAT refined analysis
  42. GRB 050802.422: Fading of the afterglow and detection of the host
  43. GRB 050803: Magellan Observations
  44. GRB 050803: early Swift XRT analysis results
  45. GRB 050803: TAROT optical limits
  46. GRB050802: Tentative absorption redshift
  47. GRB050803: Swift-BAT detection of a very long burst
  48. GCN GRB observation 050713A
  49. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  50. GRB 050802: Swift/UVOT optical and UV detections
  51. GRB050802: CrAO optical observations
  52. GRB050801: Unchanged decay slope
  53. GRB050802 radio non-detection
  54. GRB 050730: OHP optical observations
  55. GRB 050802: early Swift XRT analysis results
  56. GRB 050802: Swift/UVOT observations
  57. GRB 050802 : Lulin Optical follow-up observation
  58. GRB 050802: Swift-BAT refined analysis
  59. GRB050801: Optical photometry and decay index
  60. GRB 050802: XRT position
  61. GRB 050802: Swift Gamma-ray Burst
  62. GRB050801: Swift/UVOT Optical and UV detections
  63. GRB 050730: Preliminary Analysis of MIKE Spectrum
  64. GCN 050801: early Swift XRT analysis results
  65. GRB 050801: Swift-BAT refined analysis
  66. GRB 050801, SMARTS optical/IR afterglow observations
  67. GRB 050801, afterglow observations
  68. GRB 050730, corrected photometry and break?
  69. GRB 050801: ROTSE-III Early Afterglow Break
  70. GRB050801: Swift-BAT detection of a burst
  71. GRB050801: GCN XRT position is incorrect
  72. GRB 050801: ROTSE-III Detection of Possible Counterpart
  73. GRB 050730: XRT refined analysis
  74. Correction to GCN Circ 3476 on GRB050525A
  75. GRB 050730: early TAROT optical observations
  76. GRB 050730: RTT150 optical observations
  77. Swift/UVOT photometry of GRB050730
  78. GRB 050730, spectra and optical photometry
  79. GRB050730: Refined BAT analysis of the Swift-BAT burst
  80. GRB 050730: Swift XRT afterglow observations
  81. GRB 050730 XMM-Newton observation
  82. GRB 050730: PROMPT VRcIc Observations
  83. GRB050730, afterglow observations
  84. GRB050730: confirmation of redshift
  85. GRB 050730: Redshift Measurement based on Magellan/MIKE Observations
  86. GRB 050730, SMARTS optical/IR afterglow observations
  87. GRB050730: Liverpool Telescope optical observations
  88. GRB 050730, optical candidate
  89. GRB050730: Swift-BAT detection of a weak burst
  90. GRB 050713A: Swift XRT extended light curve
  91. GRB 050709: PROMPT Rc Observations
  92. GRB 050724: Secure Host Redshift from Keck
  93. GRB 050724: WHT optical observations
  94. GRB050726: Swift UVOT observations
  95. GRB 050724: Chandra Observations of the X-ray Afterglow
  96. GRB050724: Refined Radio Position
  97. GRB050713: analysis of the XMM-Newton observation
  98. GRB 050724, SMARTS optical/IR afterglow observations
  99. GRB 050726, SMARTS optical/IR observations
  100. Swift-BAT trigger 147918 is not a real GRB

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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