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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

32546 results found.

  1. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  2. ZTF23aaoohpy/AT2023lc: Mondy optical observations
  3. IPN triangulation of GRB 230616A (short)
  4. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  5. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  6. AT2023lcr: Pan-STARRS & ATLAS Observations
  7. ZTF23aaoohpy/AT2023lcr: Keck/LRIS spectroscopy and redshift
  8. ZTF23aaoohpy/AT2023lcr: Xinglong-2.16m optical observations
  9. LIGO/Virgo/KAGRA S230615az: Wendelstein observations of DESI galaxies and GIT candidates
  10. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  11. ZTF23aaoohpy/AT2023lcr: OHP/T193 and OHP/T120 optical follow-up observations
  12. ZTF23aaoohpy/AT2023lcr: GROWTH-India Telescope follow-up observations
  13. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  14. ZTF23aaoohpy/AT2023lcr: GOTO early optical observations and constraint
  15. LIGO/Virgo/KAGRA S230615az: GRANDMA observations of GOTO and GIT candidates
  16. GRB 230618A: Swift/UVOT Upper Limits
  17. GRB 230618A: KAIT Optical Observations
  18. Swift GRB 230618A: Global MASTER-Net observations report
  19. GRB230618A: LCOGT Optical Observations
  20. GRB 230616A: Swift ToO observations
  21. LIGO/Virgo/KAGRA S230615az: Non-Detections of GROWTH-India Candidates from GECKO Optical Observations
  22. GRB 230614C: GRBAlpha detection
  23. GRB 230616A: AstroSat CZTI detection
  24. LIGO/Virgo/KAGRA S230615az: Xinglong-2.16m photometric observations of GIT candidates
  25. GRB 230614C: AstroSat CZTI detection
  26. GRB 230614B: Fermi GBM Observation
  27. GRB 230614B: Swift/BAT-GUANO detection outside the coded FOV
  28. GRB 230606A: LCOGT Optical Observations
  29. LIGO/Virgo/KAGRA S230608as: Updated Sky localization
  30. LIGO/Virgo/KAGRA S230606d: Updated Sky localization
  31. LIGO/Virgo/KAGRA S230609u: Updated Sky localization
  32. GRB 230608A: CALET Gamma-Ray Burst Monitor detection
  33. GRB 230608A: AstroSat CZTI detection
  34. LIGO/Virgo/KAGRA S230609u: Identification of a GW compact binary merger candidate
  35. ZTF23aamxeqf/AT2023jxk: 1.3m DFOT Optical upper limit
  36. LIGO/Virgo/KAGRA S230608as: Identification of a GW compact binary merger candidate
  37. Fermi GRB 230603A: Global MASTER-Net observations report
  38. GRB 230506B: Chandra localization of the X-ray afterglow
  39. GRB 230606A: Swift-BAT refined analysis
  40. GRB 230606A: Gaoyazi/GOT optical upper limit
  41. GRB 230606A: Fermi GBM Observation
  42. GRB 230604A: GRBAlpha detection
  43. GRB 230606A: Swift/UVOT Upper Limits
  44. LIGO/Virgo/KAGRA S230606d: Identification of a GW compact binary merger candidate
  45. Fermi-LAT gamma-ray observations of IceCube-230603A
  46. LIGO/Virgo/KAGRA S230605o: Updated Sky localization
  47. IceCube-230603A: Upper limits from a search for additional neutrino events in IceCube
  48. LIGO/Virgo/KAGRA S230601bf: Updated Sky localization
  49. LIGO/Virgo/KAGRA S230605o: Identification of a GW compact binary merger candidate
  50. LIGO/Virgo/KAGRA S230601bf: Identification of a GW compact binary merger candidate
  51. GRB 230525A: CALET Gamma-Ray Burst Monitor detection
  52. LIGO/Virgo/KAGRA S230529ay: Upper limits from CALET observations.
  53. LIGO/Virgo/KAGRA S230529ay: Coverage and upper limits from MAXI/GSC observations
  54. LIGO/Virgo/KAGRA S230529ay: Upper limits from Fermi-GBM Observations
  55. LIGO/Virgo/KAGRA S230529ay: Updated Sky localization and EM Bright Classification
  56. LIGO/Virgo/KAGRA S230529ay: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  57. LIGO/Virgo/KAGRA S230529ay: Identification of a GW compact binary merger candidate
  58. LIGO/Virgo/KAGRA S230518h: Updated Sky localization
  59. LIGO/Virgo/KAGRA S230520ae: Updated Sky localization
  60. Fermi-LAT gamma-ray observations of IceCube-230524A
  61. LIGO/Virgo/KAGRA S230518h: Upper limits from Glowbug gamma-ray observations
  62. GRB 230510A: Swift-BAT refined analysis
  63. GRB 230525A: Fermi GBM Detection
  64. LIGO/Virgo/KAGRA S230518h: TESS observations of the localization region
  65. GRB 230523B: GRBAlpha detection
  66. GRB 230524A: Fermi GBM Observation
  67. GRB 230524A: AstroSat CZTI detection
  68. GRB 230524A: AGILE detection
  69. LIGO/Virgo/KAGRA S230521k: MASTER new OT discovery
  70. GRB 230523B: Name correction from GCN Circular 33859
  71. LIGO/Virgo/KAGRA S230521k: Additional candidates from Zwicky Transient Facility
  72. LIGO/Virgo/KAGRA S230518h: Swift/UVOT Upper Limits for MeerLICHT candidates: AT2023ixg and AT2023iyb
  73. GRB 230518B: VZLUSAT-2 detection
  74. Fermi Gamma-ray Burst Monitor trigger 706338208/230521211 is not a GRB
  75. IPN triangulation of GRB 230518A (short)
  76. GRB 230520A: CALET Gamma-Ray Burst Monitor detection
  77. LIGO/Virgo/KAGRA S230520ae: Identification of a GW compact binary merger candidate: End-to-End Test
  78. GRB 230520B is not a GRB
  79. LIGO/Virgo/KAGRA S230518h: ATCA follow-up of candidate counterparts
  80. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  81. LIGO/Virgo/KAGRA S230518h: Swift/UVOT Upper Limits for Swope candidates: SSS23a, SSS23b and SSS23c
  82. LIGO/Virgo/KAGRA S230518h: ATLAS observations of the skymap
  83. LIGO/Virgo/KAGRA S230518h: Swope Search and Candidate Counterpart Identification
  84. GRB 230518A: Fermi GBM Observation
  85. LIGO/Virgo/KAGRA S230518h: Upper limits from Konus-Wind observations
  86. GRB 230518A: Swift/BAT-GUANO detection
  87. LIGO/Virgo/KAGRA S230518h: Coverage and upper limits from MAXI/GSC observations
  88. LIGO/Virgo/KAGRA S230518h: AstroSat CZTI non-detection and upper limits
  89. LIGO/Virgo/KAGRA S230518h: Upper limits from Fermi-GBM Observations
  90. LIGO/Virgo/KAGRA S230518h: Updated Sky localization and EM Bright Classification
  91. LIGO/Virgo S230518h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  92. LIGO/Virgo/KAGRA S230518h: Identification of a GW compact binary merger candidate
  93. GRB 230513A: Zwicky Transient Facility continuous observations of a Fermi Short GRB (Trigger 705709044)
  94. GRB 230510B: GRBAlpha detection
  95. Improved IPN triangulation of GRB 230512A
  96. GRB 230510B: Fermi GBM detection
  97. IPN triangulation of GRB 230511D (short)
  98. IPN triangulation of GRB 230512A
  99. GRB 230513A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  100. GRB 230512A: Nanshan/NEXT non-detection of GRB afterglow candidate

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