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"

36144 results found.

  1. GRB 231117A: SOAR/Goodman imaging of the afterglow
  2. GRB 231118A: Swift detection of a burst
  3. GRB 231118A: Fermi GBM Final Real-time Localization
  4. GRB 231117A: Lowell Discovery Telescope Observations
  5. GRB 231117A: ePESSTO+ host galaxy redshift confirmation
  6. GRB 231117A: ATCA detection of a radio counterpart
  7. GRB 231117A: GRBAlpha detection
  8. GRB 231117A: Keck spectroscopy of afterglow candidate
  9. GRB 231115A: Wendelstein Optical/Infrared Observations
  10. GRB 231115A: JinShan optical upper limits
  11. GRB 231117A: GIT optical follow-up
  12. GRB 231117A: LT observations consistent with fading
  13. GRB 231117A: Keck observations indicate presence of optical afterglow in z~0.3-0.5 galaxy
  14. GRB 231117A: REM optical and NIR early-time observations
  15. GRB231117A: AGILE/MCAL analysis
  16. GRB 231117A: AKO Optical Upper Limit
  17. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  18. Swift GRB 231117A: Global MASTER-Net observations report
  19. GRB 231117A (short): Glowbug gamma-ray detection
  20. GRB 231117A: ATLAS non-detection of an optical counterpart
  21. Konus-Wind detection of GRB 231117A (short/hard)
  22. GRB 231115A : OHP/T120 optical upper limit
  23. GRB 231115A: optical observations from INAF observatories
  24. GRB 231117A : MITSuME Akeno optical upper limits
  25. GRB 231117A: AGILE detection of a bright short burst
  26. GRB 231117A: Enhanced Swift-XRT position
  27. GRB 231117A: GOTO optical upper limits
  28. GRB 231117A: AstroSat CZTI detection of a bright short burst
  29. GRB 231117A: Swift detection of a bright short burst
  30. GRB 231115A: Non-detection of radio emission with CHIME/FRB
  31. GRB 231111A: Swift/UVOT Detection
  32. MAGIC observation of GRB 231115A, a possible magnetar giant flare
  33. GRB231115A: Liverpool Telescope imaging
  34. GRB 231115A: NuSTAR Follow-Up Observations
  35. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  36. GRB 231115A: Swift-XRT and Swift-UVOT observations
  37. Fermi GRB 231116A: Global MASTER-Net observations report
  38. Konus-Wind detection of GRB 231115A (a probable Magnetar Giant Flare from M82)
  39. GRB 231115A: AGILE/MCAL upper limits
  40. GRB 231115A: Insight-HXMT/HE detection
  41. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  42. GRB 231116A: Fermi GBM Final Real-time Localization
  43. GRB 231115A : MITSuME Akeno and Okayama optical upper limits
  44. GRB 231115A: Gaoyazi/GOT follow-up and archival observations
  45. GRB 231115A / AT2023xvj: Updated GIT analysis
  46. GRB 231115A: archival Chandra X-ray observations
  47. GRB 231115A: Upper limits from a neutrino search with IceCube
  48. GRB 231115A: Kinder observations with Lulin observatory
  49. GRB231115A: GRANDMA Observations
  50. GRB 231115A: GOTO pre-burst limits of AT2023xvj
  51. GRB 231115A: Non-detection in low-latency of gravitational waves with LIGO/Virgo/KAGRA
  52. GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
  53. GRB 231106A: TESS identification of candidate optical counterpart
  54. GRB 231115A: MASTER optical observations
  55. GRB 231115A (short): Glowbug gamma-ray detection
  56. GRB 231115A: Fermi Observations of a probable Magnetar Giant Flare from M82
  57. GRB 231115A: archival HST observations
  58. GRB 231115A: GROWTH-India discovery of a potential optical counterpart
  59. GRB 231115A: Swift ToO observations
  60. Fermi GRB 231115A: Global MASTER-Net observations report
  61. GRB 231115A: significance of INTEGRAL localization alignment with M82
  62. GRB 231115A: a short hard GRB detected by IBAS, poistionally coincident with M82
  63. GRB 231115A position consistent with M 82 galaxy
  64. GRB 231115A: Fermi GBM Final Real-time Localization
  65. GRB 231111A: Swift-BAT refined analysis
  66. Fermi GRB 231114A: Global MASTER-Net observations report
  67. GRB 231113A (short): Glowbug gamma-ray detection
  68. GRB 231114A (short): Glowbug gamma-ray detection
  69. GRB 231114A: Fermi GBM Final Localization
  70. SGRJ1555-5402: Swift/BAT-GUANO arcminute localization of a SGR flare
  71. LIGO/Virgo/KAGRA S231113bw: Upper limits from Fermi-GBM Observations
  72. GRB 231110A: CALET Gamma-Ray Burst Monitor detection
  73. GRB 231110A: Swift-BAT refined analysis
  74. GRB231111A: MDM 2.4m Hiltner Telescope Observation
  75. GRB 231106A: Glowbug gamma-ray detection
  76. GRB 231111A: Xinglong-2.16m optical observations
  77. GRB 231110A: Swift-UVOT Upper Limits
  78. GRB 231111A: Afterglow redshift from OSIRIS+/GTC
  79. GRB 231104A: VZLUSAT-2 detection
  80. GRB 231111A: TNG tentative redshift
  81. GRB 231110A: Glowbug gamma-ray detection
  82. GRB 231110A: AstroSat CZTI detection
  83. GRB 231111A NUTTelA-TAO / BSTI Early Measurements
  84. GRB 231111A: Leavitt Observatory optical observations
  85. GRB231111A: Optical follow-up observations with Mephisto
  86. GRB 231111A: GMG observation (correction)
  87. GRB 231111A: GMG observation upper limit
  88. GRB 231106B: GRBAlpha detection
  89. GRB 231111A: Osservatorio Astronomico "Nastro Verde" optical observations with detection of an optical counterpart
  90. GRB 231110A: Terskol Zeiss-2000 optical upper limit
  91. GRB 231111A: Swift-XRT refined Analysis
  92. GRB 231111A: Mondy optical observations
  93. GRB 231111A: GECAM-C detection of a long burst (correction)
  94. GRB 231110A: GECAM-B detection (correction)
  95. GRB 231111A: Enhanced Swift-XRT position
  96. GRB 231111A: GECAM-C detection of a long burst
  97. GRB 231110A: GECAM detection
  98. GRB 231110A: GOTO optical upper limits
  99. GRB 231110A: SAO RAS optical observations
  100. GRB 231110A: Swift-XRT afterglow detection

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