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"

3616 results found.

  1. LIGO/Virgo S230608aw: Global MASTER-Net observations report
  2. LIGO/Virgo/KAGRA S230609u: Identification of a GW compact binary merger candidate
  3. LIGO/Virgo S230608as: Global MASTER-Net observations report
  4. LIGO/Virgo S230609a: Global MASTER-Net observations report
  5. LIGO/Virgo S230608ah: Global MASTER-Net observations report
  6. LIGO/Virgo S230608q: Global MASTER-Net observations report
  7. LIGO/Virgo/KAGRA S230608as: Identification of a GW compact binary merger candidate
  8. LIGO/Virgo/KAGRA S230602ap: Zwicky Transient Facility observations
  9. LIGO/Virgo S230606z: Global MASTER-Net observations report
  10. LIGO/Virgo S230606d: Global MASTER-Net observations report
  11. LIGO/Virgo/KAGRA S230606d: Identification of a GW compact binary merger candidate
  12. LIGO/Virgo/KAGRA S230605o: Updated Sky localization
  13. LIGO/Virgo/KAGRA S230601bf: Updated Sky localization
  14. LIGO/Virgo/KAGRA S230605o: Identification of a GW compact binary merger candidate
  15. LIGO/Virgo S230605o: Global MASTER-Net observations report
  16. LIGO/Virgo S230604z: Global MASTER-Net observations report
  17. LIGO/Virgo S230603aa: Global MASTER-Net observations report
  18. LIGO/Virgo S230602ap: Global MASTER-Net observations report
  19. LIGO/Virgo/KAGRA S230518h: Upper limits from a two-week IceCube neutrino search
  20. LIGO/Virgo S230601bf: Global MASTER-Net observations report
  21. LIGO/Virgo/KAGRA S230601bf: Identification of a GW compact binary merger candidate
  22. LIGO/Virgo S230531f: Global MASTER-Net observations report
  23. LIGO/Virgo/KAGRA S230529ay: Zwicky Transient Facility observations
  24. LIGO/Virgo/KAGRA S230528a: Zwicky Transient Facility observations
  25. LIGO/Virgo/KAGRA S230527ch: Zwicky Transient Facility observations
  26. LIGO/Virgo/KAGRA S230529ay: Upper limits from CALET observations.
  27. LIGO/Virgo/KAGRA S230529ay: AstroSat CZTI non-detection and upper limits
  28. LIGO/Virgo S230529ay: Global MASTER-Net observations report
  29. LIGO/Virgo/KAGRA S230529ay: upper limits from AGILE/MCAL
  30. LIGO/Virgo/KAGRA S230529ay: Coverage and upper limits from MAXI/GSC observations
  31. LIGO/Virgo/KAGRA S230529ay: Upper limits from Fermi-GBM Observations
  32. LIGO/Virgo/KAGRA S230529ay: Updated Sky localization and EM Bright Classification
  33. LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  34. LIGO/Virgo/KAGRA S230529ay: Identification of a GW compact binary merger candidate
  35. LIGO/Virgo S230529p: Global MASTER-Net observations report
  36. LIGO/Virgo S230525a: Global MASTER-Net observations report
  37. LIGO/Virgo/KAGRA S230518h: Updated Sky localization
  38. LIGO/Virgo/KAGRA S230520ae: Updated Sky localization
  39. LIGO/Virgo/KAGRA S230518h: Upper limits from Glowbug gamma-ray observations
  40. LIGO/Virgo/KAGRA S230518h: TESS observations of the localization region
  41. LIGO/Virgo/KAGRA S230518h: No transient candidates in CALET observations
  42. LIGO/Virgo/KAGRA S230524x: Retraction of GW compact binary merger candidate
  43. LIGO/Virgo S230524b: Global MASTER-Net observations report
  44. LIGO/Virgo/KAGRA S230521k: MASTER new OT discovery
  45. LIGO/Virgo/KAGRA S230521k: Additional candidates from Zwicky Transient Facility
  46. LIGO/Virgo S230522n: Global MASTER-Net observations report
  47. LIGO/Virgo S230522a: Global MASTER-Net observations report
  48. LIGO/Virgo/KAGRA S230522n: Upper limits from IceCube neutrino search
  49. LIGO/Virgo/KAGRA S230518h: Swift/UVOT Upper Limits for MeerLICHT candidates: AT2023ixg and AT2023iyb
  50. LIGO/Virgo/KAGRA S230522a: 2 counterpart neutrino candidates from IceCube neutrino searches
  51. LIGO/Virgo S230521k: Global MASTER-Net observations report
  52. LIGO/Virgo/KAGRA S230521k: Zwicky Transient Facility observations
  53. LIGO/Virgo S230520ae: Global MASTER-Net observations report
  54. LIGO/Virgo/KAGRA S230520ae: Identification of a GW compact binary merger candidate: End-to-End Test
  55. LIGO/Virgo/KAGRA S230520ae: Upper limits from IceCube neutrino search
  56. LIGO/Virgo/KAGRA S230518h: ATCA follow-up of candidate counterparts
  57. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  58. LIGO/Virgo/KAGRA S230518h: Swift/UVOT Upper Limits for Swope candidates: SSS23a, SSS23b and SSS23c
  59. LIGO/Virgo/KAGRA S230518h: ATLAS observations of the skymap
  60. LIGO/Virgo/KAGRA S230518h: Swope Search and Candidate Counterpart Identification
  61. LIGO/Virgo/KAGRA S230518h: Upper limits from Konus-Wind observations
  62. LIGO/Virgo S230518h: AGILE/MCAL observations
  63. LIGO/Virgo S230518h: Swift XRT observations, 8 X-ray sources
  64. LIGO/Virgo/KAGRA S230518h: Coverage and upper limits from MAXI/GSC observations
  65. LIGO/Virgo/Kagra S230518h: NED Galaxies in the Localization Volume
  66. LIGO/Virgo/KAGRA S230518h: AstroSat CZTI non-detection and upper limits
  67. LIGO/Virgo/KAGRA S230518h: Upper limits from Fermi-GBM Observations
  68. LIGO/Virgo S230518h: Global MASTER-Net observations report
  69. LIGO/Virgo/KAGRA S230518h: Updated Sky localization and EM Bright Classification
  70. LIGO/Virgo S230518h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  71. LIGO/Virgo S230518h: Upper limits from IceCube neutrino search
  72. LIGO/Virgo/KAGRA S230518h: Identification of a GW compact binary merger candidate
  73. LIGO-Virgo-KAGRA and GEO600 statement on GRB 221009A
  74. ZTF22aabjpxh/AT2022cva: NICER X-ray detection is consistent with a GRB afterglow
  75. ZTF22aaajecp/AT2022cmc: NICER X-ray detection
  76. LIGO/Virgo MS200618aq: Retraction of a test binary neutron star candidate
  77. LIGO/Virgo MS200619bf: Retraction of a test binary neutron star candidate
  78. LIGO/Virgo MS200618bx: Retraction of a test binary neutron star candidate
  79. LIGO/Virgo MS200618bq: Retraction of a test binary neutron star candidate
  80. LIGO/Virgo MS200614ct: Identification of a test binary black hole candidate
  81. LIGO/Virgo MS200615ce: Identification of a test binary black hole candidate
  82. LIGO/Virgo MS200614bz: Test Identification of a binary neutron star candidate
  83. LIGO/Virgo MS200615h: Retraction of a test binary neutron star candidate
  84. LIGO/Virgo S200225q: Swift XRT observations, 1 X-ray sources
  85. LIGO/Virgo S200224ca: Swift XRT observations, 8 X-ray sources
  86. LIGO/Virgo S200316bj: Upper limits from Konus-Wind observations
  87. LIGO/Virgo S200311bg: Upper limits from Konus-Wind observations
  88. LIGO/Virgo S200302c: Upper limits from Konus-Wind observations
  89. LIGO/Virgo S200225q: Upper limits from Konus-Wind observations
  90. LIGO/Virgo S200224ca: Upper limits from Konus-Wind observations
  91. LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC-F30 observations
  92. LIGO/Virgo S200316bj: Updated Sky Localization and EM Bright Classification
  93. LIGO/Virgo S200316bj : No significant candidates in TAROT - FRAM - GRANDMA observations.
  94. LIGO/Virgo S200316bj: Upper limits from Insight-HXMT/HE observations
  95. LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC observations
  96. LIGO/Virgo S200316bj: Upper limits from CALET observations
  97. LIGO/Virgo S200316bj: No neutrino candidates at Pierre Auger Observatory
  98. LIGO/Virgo S200316bj: No counterpart candidates in Fermi-LAT observations
  99. LIGO/Virgo S200316bj: No Counterparts in DDOTI/OAN Optical Observations
  100. LIGO/Virgo S200316bj: no counterpart candidates in the Swift/BAT observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov